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Re: [beam] Re: OT: 555IC LED Fader/Pulser thinger.

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  • Chris McGuire
    Thank you for looking at this! You re totally right, it isn t the most elegant solution for what I m doing. I really need all 9v to be handy, it s to be used
    Message 1 of 11 , Mar 1, 2009
      Thank you for looking at this! You're totally right, it isn't the most elegant solution for what I'm doing. I really need all 9v to be handy, it's to be used on a 13 LED array. This circuit is just a messy way of doing it. I think I'll be a lot happier with it when I simply wait for the assortment of AVR chips I have on order to arrive, and program the PWM to be exactly how I'll want it. 

      Basically, what I've made, is a heart-shaped LED array, and I am wanting it to pulse like a human's heartbeat. It's an upgrade to a valentine's day gift I gave. I bought a small painting canvas, 4x4 inches, and removed the canvas from the frame, and wired my array through it, after painting the canvas a solid matte black. The canvas is about 1.5 inches deep, with a hole in the back- which works nicely to hold the battery + a little extra space for a PCB+IC. I dremel'd a little slot for the PCB and a larger one for the 9v battery, and made a clean little lid for it with some balsa. Then, I re-assembled the canvas, making it all nice and tight, so the LED's (mostly big 10mm red and frosted blues) stand up straight. Then, for a switch, I took a simple pressure switch, fastened it to the bottom back edge, and got a wooden easel to set it on. When the frame is on the easel, it's on, when it's off, it's off. Fits nice and works well. 

      So, I think the best solution for this one is to do it right- I'll take 4 or so of my own heart's pulse rates, make an average, then program the AVR thusly. This would look much better than using a 555 for it. I'm just being impatient :)

      Thanks, all!

      Chris


      On Feb 28, 2009, at 1:51 PM, wilf_nv wrote:



      I asume the circuit is meant to alternately fade the LEDs on and then 
      fade the LEDs off. 

      I see how this would work but there is a missing connection that 
      should connect 555 pin 2, pin 6 and the (+) side of the cap together 
      and pin 7 must be left unconnected. This is why the circuit is not 
      working.

      This 555 astable circuit was designed to generate a slow changing 
      triangular voltage waveform at the base of the transistor which 
      controls the current through the LEDs. The 100k resistor connected 
      between the output pin 3 and the 100uf cap, discharges and charges 
      the cap between 3V and 6v (with a 9V supply). 

      Even when made fully fuctional, the LEDs are not very bright and the 
      circuit is not an elegant solution for what it is supposed to do. 

      I you have two 555 timers or a 556 dual timer you can make a much 
      nicer design.

      wilf

      -- In beam@yahoogroups. com, Chris McGuire <cmcguire@.. .> wrote:
      >
      > Oh, yeah! Duh. The only difference here, is that he's got 4 LED's 
      > down, and I'm trying to use this on a LED array, to make them all 
      go 
      > at once. Here it is..
      > 
      > http://www.instruct ables.com/ file/F4J70N0FRAA PMYY/
      > 
      > Thanks!!
      > 
      > 
      > On Feb 28, 2009, at 12:18 PM, m3lt79 wrote:
      > 
      > > It would help if you provide the schematic you are using.
      > >
      > > --- In beam@yahoogroups. com, Chris McGuire <cmcguire@> wrote:
      > > >
      > > > Hello all!
      > > >
      > > > I am looking for a way to use a 555 timer to fade a LED array 
      in and
      > > > out, not blinky. I've found a schematic for it, but there's 
      > > something
      > > > up with it- either I or it's is wrong. Does anyone have such 
      info 
      > > handy?
      > > >
      > > > Thank you!
      > > >
      > > > Chris
      > > >
      > >
      > >
      > >
      >


    • wilf_nv
      With some small mods the circuit should work fine for your application. I posted the schematic in the file section. By adding Q2 to drive Q1 a quasi darlington
      Message 2 of 11 , Mar 1, 2009
        With some small mods the circuit should work fine for your
        application. I posted the schematic in the file section.

        By adding Q2 to drive Q1 a quasi darlington is created with high
        input resistance to decrease the loading of the capacitor node. With
        R2=33ohm, the LED current will be 130mA which can drive 13 paralell
        LEDs to high brightenss. The LEDs should be from one batch and
        matched for equal brightness.

        Resistor R2 was put on the emitter of output transistor Q1 to make
        the driver a voltage controlled current source, less sensitive to
        power supply variations. Adjust R1 value or replace with 100K pot
        for frequency control. Adjust R2 value between 33 ohm and 100ohm
        for brightness control.

        By adding a light dependent resistor (LDR nominal 10K in light) from
        555 pin 5 to 0V, the LED brightness is decreased and off time is
        increased. When shaded by an onlooker, the heart grows brighter.

        wilf



        --- In beam@yahoogroups.com, Chris McGuire <cmcguire@...> wrote:
        >
        > Thank you for looking at this! You're totally right, it isn't the
        > most elegant solution for what I'm doing. I really need all 9v to
        be
        > handy, it's to be used on a 13 LED array. This circuit is just a
        > messy way of doing it. I think I'll be a lot happier with it when
        I
        > simply wait for the assortment of AVR chips I have on order to
        > arrive, and program the PWM to be exactly how I'll want it.
        >
        > Basically, what I've made, is a heart-shaped LED array, and I am
        > wanting it to pulse like a human's heartbeat. It's an upgrade to a
        > valentine's day gift I gave. I bought a small painting canvas, 4x4
        > inches, and removed the canvas from the frame, and wired my array
        > through it, after painting the canvas a solid matte black. The
        canvas
        > is about 1.5 inches deep, with a hole in the back- which works
        nicely
        > to hold the battery + a little extra space for a PCB+IC. I dremel'd
        a
        > little slot for the PCB and a larger one for the 9v battery, and
        made
        > a clean little lid for it with some balsa. Then, I re-assembled
        the
        > canvas, making it all nice and tight, so the LED's (mostly big
        10mm
        > red and frosted blues) stand up straight. Then, for a switch, I
        took
        > a simple pressure switch, fastened it to the bottom back edge, and
        > got a wooden easel to set it on. When the frame is on the easel,
        it's
        > on, when it's off, it's off. Fits nice and works well.
        >
        > So, I think the best solution for this one is to do it right- I'll
        > take 4 or so of my own heart's pulse rates, make an average, then
        > program the AVR thusly. This would look much better than using a
        555
        > for it. I'm just being impatient :)
        >
        > Thanks, all!
        >
        > Chris
        >
        >
        > On Feb 28, 2009, at 1:51 PM, wilf_nv wrote:
        >
        > >
        > >
        > > I asume the circuit is meant to alternately fade the LEDs on and
        then
        > > fade the LEDs off.
        > >
        > > I see how this would work but there is a missing connection that
        > > should connect 555 pin 2, pin 6 and the (+) side of the cap
        together
        > > and pin 7 must be left unconnected. This is why the circuit is not
        > > working.
        > >
        > > This 555 astable circuit was designed to generate a slow changing
        > > triangular voltage waveform at the base of the transistor which
        > > controls the current through the LEDs. The 100k resistor connected
        > > between the output pin 3 and the 100uf cap, discharges and charges
        > > the cap between 3V and 6v (with a 9V supply).
        > >
        > > Even when made fully fuctional, the LEDs are not very bright and
        the
        > > circuit is not an elegant solution for what it is supposed to do.
        > >
        > > I you have two 555 timers or a 556 dual timer you can make a much
        > > nicer design.
        > >
        > > wilf
        > >
        > > -- In beam@yahoogroups.com, Chris McGuire <cmcguire@> wrote:
        > > >
        > > > Oh, yeah! Duh. The only difference here, is that he's got 4
        LED's
        > > > down, and I'm trying to use this on a LED array, to make them
        all
        > > go
        > > > at once. Here it is..
        > > >
        > > > http://www.instructables.com/file/F4J70N0FRAAPMYY/
        > > >
        > > > Thanks!!
        > > >
        > > >
        > > > On Feb 28, 2009, at 12:18 PM, m3lt79 wrote:
        > > >
        > > > > It would help if you provide the schematic you are using.
        > > > >
        > > > > --- In beam@yahoogroups.com, Chris McGuire <cmcguire@> wrote:
        > > > > >
        > > > > > Hello all!
        > > > > >
        > > > > > I am looking for a way to use a 555 timer to fade a LED
        array
        > > in and
        > > > > > out, not blinky. I've found a schematic for it, but there's
        > > > > something
        > > > > > up with it- either I or it's is wrong. Does anyone have such
        > > info
        > > > > handy?
        > > > > >
        > > > > > Thank you!
        > > > > >
        > > > > > Chris
        > > > > >
        > > > >
        > > > >
        > > > >
        > > >
        > >
        > >
        > >
        >
      • Chris McGuire
        Wow, thank you, Wilf!! That s way above and beyond.. I think I will have to make another one! The first one I made is 4 groups of 3, with the extra hanging out
        Message 3 of 11 , Mar 1, 2009
          Wow, thank you, Wilf!!

          That's way above and beyond.. I think I will have to make another one! The first one I made is 4 groups of 3, with the extra hanging out with a bigger resistor. But your design is so great, especially with the LDR adding some interactivity to it- that's just brilliant! I will certainly post a video of this one when it's done. Thank you so much!

          Chris


          On Mar 1, 2009, at 2:18 PM, wilf_nv wrote:

          With some small mods the circuit should work fine for your 
          application. I posted the schematic in the file section.

          By adding Q2 to drive Q1 a quasi darlington is created with high 
          input resistance to decrease the loading of the capacitor node. With 
          R2=33ohm, the LED current will be 130mA which can drive 13 paralell 
          LEDs to high brightenss. The LEDs should be from one batch and 
          matched for equal brightness.

          Resistor R2 was put on the emitter of output transistor Q1 to make 
          the driver a voltage controlled current source, less sensitive to 
          power supply variations. Adjust R1 value or replace with 100K pot 
          for frequency control. Adjust R2 value between 33 ohm and 100ohm 
          for brightness control. 

          By adding a light dependent resistor (LDR nominal 10K in light) from 
          555 pin 5 to 0V, the LED brightness is decreased and off time is 
          increased. When shaded by an onlooker, the heart grows brighter. 

          wilf

          --- In beam@yahoogroups. com, Chris McGuire <cmcguire@.. .> wrote:
          >
          > Thank you for looking at this! You're totally right, it isn't the 
          > most elegant solution for what I'm doing. I really need all 9v to 
          be 
          > handy, it's to be used on a 13 LED array. This circuit is just a 
          > messy way of doing it. I think I'll be a lot happier with it when 
          I 
          > simply wait for the assortment of AVR chips I have on order to 
          > arrive, and program the PWM to be exactly how I'll want it.
          > 
          > Basically, what I've made, is a heart-shaped LED array, and I am 
          > wanting it to pulse like a human's heartbeat. It's an upgrade to a 
          > valentine's day gift I gave. I bought a small painting canvas, 4x4 
          > inches, and removed the canvas from the frame, and wired my array 
          > through it, after painting the canvas a solid matte black. The 
          canvas 
          > is about 1.5 inches deep, with a hole in the back- which works 
          nicely 
          > to hold the battery + a little extra space for a PCB+IC. I dremel'd 
          a 
          > little slot for the PCB and a larger one for the 9v battery, and 
          made 
          > a clean little lid for it with some balsa. Then, I re-assembled 
          the 
          > canvas, making it all nice and tight, so the LED's (mostly big 
          10mm 
          > red and frosted blues) stand up straight. Then, for a switch, I 
          took 
          > a simple pressure switch, fastened it to the bottom back edge, and 
          > got a wooden easel to set it on. When the frame is on the easel, 
          it's 
          > on, when it's off, it's off. Fits nice and works well.
          > 
          > So, I think the best solution for this one is to do it right- I'll 
          > take 4 or so of my own heart's pulse rates, make an average, then 
          > program the AVR thusly. This would look much better than using a 
          555 
          > for it. I'm just being impatient :)
          > 
          > Thanks, all!
          > 
          > Chris
          > 
          > 
          > On Feb 28, 2009, at 1:51 PM, wilf_nv wrote:
          > 
          > >
          > >
          > > I asume the circuit is meant to alternately fade the LEDs on and 
          then
          > > fade the LEDs off.
          > >
          > > I see how this would work but there is a missing connection that
          > > should connect 555 pin 2, pin 6 and the (+) side of the cap 
          together
          > > and pin 7 must be left unconnected. This is why the circuit is not
          > > working.
          > >
          > > This 555 astable circuit was designed to generate a slow changing
          > > triangular voltage waveform at the base of the transistor which
          > > controls the current through the LEDs. The 100k resistor connected
          > > between the output pin 3 and the 100uf cap, discharges and charges
          > > the cap between 3V and 6v (with a 9V supply).
          > >
          > > Even when made fully fuctional, the LEDs are not very bright and 
          the
          > > circuit is not an elegant solution for what it is supposed to do.
          > >
          > > I you have two 555 timers or a 556 dual timer you can make a much
          > > nicer design.
          > >
          > > wilf
          > >
          > > -- In beam@yahoogroups. com, Chris McGuire <cmcguire@> wrote:
          > > >
          > > > Oh, yeah! Duh. The only difference here, is that he's got 4 
          LED's
          > > > down, and I'm trying to use this on a LED array, to make them 
          all
          > > go
          > > > at once. Here it is..
          > > >
          > > > http://www.instruct ables.com/ file/F4J70N0FRAA PMYY/
          > > >
          > > > Thanks!!
          > > >
          > > >
          > > > On Feb 28, 2009, at 12:18 PM, m3lt79 wrote:
          > > >
          > > > > It would help if you provide the schematic you are using.
          > > > >
          > > > > --- In beam@yahoogroups. com, Chris McGuire <cmcguire@> wrote:
          > > > > >
          > > > > > Hello all!
          > > > > >
          > > > > > I am looking for a way to use a 555 timer to fade a LED 
          array
          > > in and
          > > > > > out, not blinky. I've found a schematic for it, but there's
          > > > > something
          > > > > > up with it- either I or it's is wrong. Does anyone have such
          > > info
          > > > > handy?
          > > > > >
          > > > > > Thank you!
          > > > > >
          > > > > > Chris
          > > > > >
          > > > >
          > > > >
          > > > >
          > > >
          > >
          > >
          > >
          >


        • wilf_nv
          Hi Chris, My pleasure. Sounds like you already build one version. How did you wire the 4 groups of 3 plus 1 LEDs? How many resistors did you use? wilf ...
          Message 4 of 11 , Mar 1, 2009
            Hi Chris,

            My pleasure. Sounds like you already build one version. How did you
            wire the 4 groups of 3 plus 1 LEDs? How many resistors did you use?

            wilf


            --- In beam@yahoogroups.com, Chris McGuire <cmcguire@...> wrote:
            >
            > Wow, thank you, Wilf!!
            >
            > That's way above and beyond.. I think I will have to make another
            > one! The first one I made is 4 groups of 3, with the extra hanging
            > out with a bigger resistor. But your design is so great,
            especially
            > with the LDR adding some interactivity to it- that's just
            brilliant!
            > I will certainly post a video of this one when it's done. Thank
            you
            > so much!
            >
            > Chris
            >
            >
            > On Mar 1, 2009, at 2:18 PM, wilf_nv wrote:
            >
            > > With some small mods the circuit should work fine for your
            > > application. I posted the schematic in the file section.
            > >
            > > By adding Q2 to drive Q1 a quasi darlington is created with high
            > > input resistance to decrease the loading of the capacitor node.
            With
            > > R2=33ohm, the LED current will be 130mA which can drive 13
            paralell
            > > LEDs to high brightenss. The LEDs should be from one batch and
            > > matched for equal brightness.
            > >
            > > Resistor R2 was put on the emitter of output transistor Q1 to make
            > > the driver a voltage controlled current source, less sensitive to
            > > power supply variations. Adjust R1 value or replace with 100K pot
            > > for frequency control. Adjust R2 value between 33 ohm and 100ohm
            > > for brightness control.
            > >
            > > By adding a light dependent resistor (LDR nominal 10K in light)
            from
            > > 555 pin 5 to 0V, the LED brightness is decreased and off time is
            > > increased. When shaded by an onlooker, the heart grows brighter.
            > >
            > > wilf
            > >
            > > --- In beam@yahoogroups.com, Chris McGuire <cmcguire@> wrote:
            > > >
            > > > Thank you for looking at this! You're totally right, it isn't
            the
            > > > most elegant solution for what I'm doing. I really need all 9v
            to
            > > be
            > > > handy, it's to be used on a 13 LED array. This circuit is just a
            > > > messy way of doing it. I think I'll be a lot happier with it
            when
            > > I
            > > > simply wait for the assortment of AVR chips I have on order to
            > > > arrive, and program the PWM to be exactly how I'll want it.
            > > >
            > > > Basically, what I've made, is a heart-shaped LED array, and I am
            > > > wanting it to pulse like a human's heartbeat. It's an upgrade
            to a
            > > > valentine's day gift I gave. I bought a small painting canvas,
            4x4
            > > > inches, and removed the canvas from the frame, and wired my
            array
            > > > through it, after painting the canvas a solid matte black. The
            > > canvas
            > > > is about 1.5 inches deep, with a hole in the back- which works
            > > nicely
            > > > to hold the battery + a little extra space for a PCB+IC. I
            dremel'd
            > > a
            > > > little slot for the PCB and a larger one for the 9v battery, and
            > > made
            > > > a clean little lid for it with some balsa. Then, I re-assembled
            > > the
            > > > canvas, making it all nice and tight, so the LED's (mostly big
            > > 10mm
            > > > red and frosted blues) stand up straight. Then, for a switch, I
            > > took
            > > > a simple pressure switch, fastened it to the bottom back edge,
            and
            > > > got a wooden easel to set it on. When the frame is on the easel,
            > > it's
            > > > on, when it's off, it's off. Fits nice and works well.
            > > >
            > > > So, I think the best solution for this one is to do it right-
            I'll
            > > > take 4 or so of my own heart's pulse rates, make an average,
            then
            > > > program the AVR thusly. This would look much better than using a
            > > 555
            > > > for it. I'm just being impatient :)
            > > >
            > > > Thanks, all!
            > > >
            > > > Chris
            > > >
            > > >
            > > > On Feb 28, 2009, at 1:51 PM, wilf_nv wrote:
            > > >
            > > > >
            > > > >
            > > > > I asume the circuit is meant to alternately fade the LEDs on
            and
            > > then
            > > > > fade the LEDs off.
            > > > >
            > > > > I see how this would work but there is a missing connection
            that
            > > > > should connect 555 pin 2, pin 6 and the (+) side of the cap
            > > together
            > > > > and pin 7 must be left unconnected. This is why the circuit
            is not
            > > > > working.
            > > > >
            > > > > This 555 astable circuit was designed to generate a slow
            changing
            > > > > triangular voltage waveform at the base of the transistor
            which
            > > > > controls the current through the LEDs. The 100k resistor
            connected
            > > > > between the output pin 3 and the 100uf cap, discharges and
            charges
            > > > > the cap between 3V and 6v (with a 9V supply).
            > > > >
            > > > > Even when made fully fuctional, the LEDs are not very bright
            and
            > > the
            > > > > circuit is not an elegant solution for what it is supposed to
            do.
            > > > >
            > > > > I you have two 555 timers or a 556 dual timer you can make a
            much
            > > > > nicer design.
            > > > >
            > > > > wilf
            > > > >
            > > > > -- In beam@yahoogroups.com, Chris McGuire <cmcguire@> wrote:
            > > > > >
            > > > > > Oh, yeah! Duh. The only difference here, is that he's got 4
            > > LED's
            > > > > > down, and I'm trying to use this on a LED array, to make
            them
            > > all
            > > > > go
            > > > > > at once. Here it is..
            > > > > >
            > > > > > http://www.instructables.com/file/F4J70N0FRAAPMYY/
            > > > > >
            > > > > > Thanks!!
            > > > > >
            > > > > >
            > > > > > On Feb 28, 2009, at 12:18 PM, m3lt79 wrote:
            > > > > >
            > > > > > > It would help if you provide the schematic you are using.
            > > > > > >
            > > > > > > --- In beam@yahoogroups.com, Chris McGuire <cmcguire@>
            wrote:
            > > > > > > >
            > > > > > > > Hello all!
            > > > > > > >
            > > > > > > > I am looking for a way to use a 555 timer to fade a LED
            > > array
            > > > > in and
            > > > > > > > out, not blinky. I've found a schematic for it, but
            there's
            > > > > > > something
            > > > > > > > up with it- either I or it's is wrong. Does anyone have
            such
            > > > > info
            > > > > > > handy?
            > > > > > > >
            > > > > > > > Thank you!
            > > > > > > >
            > > > > > > > Chris
            > > > > > > >
            > > > > > >
            > > > > > >
            > > > > > >
            > > > > >
            > > > >
            > > > >
            > > > >
            > > >
            > >
            > >
            > >
            >
          • Chris McGuire
            Hello Wilf, Yes, I ve already made and given one. I just didn t have time to work out the pulsing part of it, and had to place a mouser.com order, which
            Message 5 of 11 , Mar 1, 2009
              Hello Wilf, 

              Yes, I've already made and given one. I just didn't have time to work out the pulsing part of it, and had to place a mouser.com order, which usually takes me a while.. I usually need so many little things that I just compile a parts list, and buy at once. Otherwise, I would have just used a MCU for it, and will for the first one. But for the schematic you made, I will make a second one- I still have a few of those lovely frosted blue 10mm LED's, and some 5mm amber ones I'd like to get rid of. So, I think my newborn niece would like one wired into a star for her. I'll wire that one parallel and use your circuit, especially with the LDR, which is a fantastic touch. 

              The wiring on the LED array is very simple. I cut a heart out of paper, and made pencil marks where an LED will go. Then, I used a tack to punch holes for the anode and cathode, and pushed the LED through. Then, on the back, I made more marks to indicate the LED groups, and the positive and negative sides. Then, I simply twisted the right anodes & cathodes for each grouping together, added a little solder.. I put the resistors on the negative side, slid a little shrink-tubing on it, and soldered up wires to each side. Then, using a dime-sized circular PCB from radio shack, I combined the wires neatly. There was a single 1 ohm resistor used on each of the groups of 3, and a 330 resistor used on the single LED. It's all powered with a 9v battery, and works very well. I used the calculator at http://led.linear1.org/1led.wiz to come up with the numbers for everything. I also used liberal amounts of shrink-tube and tape to prevent any shorts when I fastened it back onto the canvas. Luckily, on the canvas I used ( http://www.dickblick.com/products/blick-studio-gallery-profile-canvas/ ) has a little indentation on the top, so the wiring fit nicely. Very simple project overall. 

              And actually, may I ask for some advice? I am self-taught at electronics. I've learned a lot, and I knew C going into this, but I really need to learn numbers and the math behind everything. Do you know of any online tutorials, or perhaps a college class or three I can take? I'm seeking a degree in another field, but I want to get good at this! But, my school is a trade school for mortuary science- no fun electives there, just a good online degree for a guy who's pushing 30 and needs to work (when there's work..)

              Thank you very much! 

              Chris

              On Mar 1, 2009, at 8:16 PM, wilf_nv wrote:



              Hi Chris,

              My pleasure. Sounds like you already build one version. How did you 
              wire the 4 groups of 3 plus 1 LEDs? How many resistors did you use? 

              wilf

              --- In beam@yahoogroups. com, Chris McGuire <cmcguire@.. .> wrote:
              >
              > Wow, thank you, Wilf!!
              > 
              > That's way above and beyond.. I think I will have to make another 
              > one! The first one I made is 4 groups of 3, with the extra hanging 
              > out with a bigger resistor. But your design is so great, 
              especially 
              > with the LDR adding some interactivity to it- that's just 
              brilliant! 
              > I will certainly post a video of this one when it's done. Thank 
              you 
              > so much!
              > 
              > Chris
              > 
              > 
              > On Mar 1, 2009, at 2:18 PM, wilf_nv wrote:
              > 
              > > With some small mods the circuit should work fine for your
              > > application. I posted the schematic in the file section.
              > >
              > > By adding Q2 to drive Q1 a quasi darlington is created with high
              > > input resistance to decrease the loading of the capacitor node. 
              With
              > > R2=33ohm, the LED current will be 130mA which can drive 13 
              paralell
              > > LEDs to high brightenss. The LEDs should be from one batch and
              > > matched for equal brightness.
              > >
              > > Resistor R2 was put on the emitter of output transistor Q1 to make
              > > the driver a voltage controlled current source, less sensitive to
              > > power supply variations. Adjust R1 value or replace with 100K pot
              > > for frequency control. Adjust R2 value between 33 ohm and 100ohm
              > > for brightness control.
              > >
              > > By adding a light dependent resistor (LDR nominal 10K in light) 
              from
              > > 555 pin 5 to 0V, the LED brightness is decreased and off time is
              > > increased. When shaded by an onlooker, the heart grows brighter.
              > >
              > > wilf
              > >
              > > --- In beam@yahoogroups. com, Chris McGuire <cmcguire@> wrote:
              > > >
              > > > Thank you for looking at this! You're totally right, it isn't 
              the
              > > > most elegant solution for what I'm doing. I really need all 9v 
              to
              > > be
              > > > handy, it's to be used on a 13 LED array. This circuit is just a
              > > > messy way of doing it. I think I'll be a lot happier with it 
              when
              > > I
              > > > simply wait for the assortment of AVR chips I have on order to
              > > > arrive, and program the PWM to be exactly how I'll want it.
              > > >
              > > > Basically, what I've made, is a heart-shaped LED array, and I am
              > > > wanting it to pulse like a human's heartbeat. It's an upgrade 
              to a
              > > > valentine's day gift I gave. I bought a small painting canvas, 
              4x4
              > > > inches, and removed the canvas from the frame, and wired my 
              array
              > > > through it, after painting the canvas a solid matte black. The
              > > canvas
              > > > is about 1.5 inches deep, with a hole in the back- which works
              > > nicely
              > > > to hold the battery + a little extra space for a PCB+IC. I 
              dremel'd
              > > a
              > > > little slot for the PCB and a larger one for the 9v battery, and
              > > made
              > > > a clean little lid for it with some balsa. Then, I re-assembled
              > > the
              > > > canvas, making it all nice and tight, so the LED's (mostly big
              > > 10mm
              > > > red and frosted blues) stand up straight. Then, for a switch, I
              > > took
              > > > a simple pressure switch, fastened it to the bottom back edge, 
              and
              > > > got a wooden easel to set it on. When the frame is on the easel,
              > > it's
              > > > on, when it's off, it's off. Fits nice and works well.
              > > >
              > > > So, I think the best solution for this one is to do it right- 
              I'll
              > > > take 4 or so of my own heart's pulse rates, make an average, 
              then
              > > > program the AVR thusly. This would look much better than using a
              > > 555
              > > > for it. I'm just being impatient :)
              > > >
              > > > Thanks, all!
              > > >
              > > > Chris
              > > >
              > > >
              > > > On Feb 28, 2009, at 1:51 PM, wilf_nv wrote:
              > > >
              > > > >
              > > > >
              > > > > I asume the circuit is meant to alternately fade the LEDs on 
              and
              > > then
              > > > > fade the LEDs off.
              > > > >
              > > > > I see how this would work but there is a missing connection 
              that
              > > > > should connect 555 pin 2, pin 6 and the (+) side of the cap
              > > together
              > > > > and pin 7 must be left unconnected. This is why the circuit 
              is not
              > > > > working.
              > > > >
              > > > > This 555 astable circuit was designed to generate a slow 
              changing
              > > > > triangular voltage waveform at the base of the transistor 
              which
              > > > > controls the current through the LEDs. The 100k resistor 
              connected
              > > > > between the output pin 3 and the 100uf cap, discharges and 
              charges
              > > > > the cap between 3V and 6v (with a 9V supply).
              > > > >
              > > > > Even when made fully fuctional, the LEDs are not very bright 
              and
              > > the
              > > > > circuit is not an elegant solution for what it is supposed to 
              do.
              > > > >
              > > > > I you have two 555 timers or a 556 dual timer you can make a 
              much
              > > > > nicer design.
              > > > >
              > > > > wilf
              > > > >
              > > > > -- In beam@yahoogroups. com, Chris McGuire <cmcguire@> wrote:
              > > > > >
              > > > > > Oh, yeah! Duh. The only difference here, is that he's got 4
              > > LED's
              > > > > > down, and I'm trying to use this on a LED array, to make 
              them
              > > all
              > > > > go
              > > > > > at once. Here it is..
              > > > > >
              > > > > > http://www.instruct ables.com/ file/F4J70N0FRAA PMYY/
              > > > > >
              > > > > > Thanks!!
              > > > > >
              > > > > >
              > > > > > On Feb 28, 2009, at 12:18 PM, m3lt79 wrote:
              > > > > >
              > > > > > > It would help if you provide the schematic you are using.
              > > > > > >
              > > > > > > --- In beam@yahoogroups. com, Chris McGuire <cmcguire@> 
              wrote:
              > > > > > > >
              > > > > > > > Hello all!
              > > > > > > >
              > > > > > > > I am looking for a way to use a 555 timer to fade a LED
              > > array
              > > > > in and
              > > > > > > > out, not blinky. I've found a schematic for it, but 
              there's
              > > > > > > something
              > > > > > > > up with it- either I or it's is wrong. Does anyone have 
              such
              > > > > info
              > > > > > > handy?
              > > > > > > >
              > > > > > > > Thank you!
              > > > > > > >
              > > > > > > > Chris
              > > > > > > >
              > > > > > >
              > > > > > >
              > > > > > >
              > > > > >
              > > > >
              > > > >
              > > > >
              > > >
              > >
              > >
              > >
              >


            • wilf_nv
              I mentioned matching LEDs but it sounds like you may be using a variety of LEDs in different groups. For better control of each LED brightness use individual
              Message 6 of 11 , Mar 1, 2009
                I mentioned matching LEDs but it sounds like you may be using a
                variety of LEDs in different groups. For better control of each LED
                brightness use individual series resistors for each LED and then wire
                these LED/resistor pairs all in parallel. That requires a change in
                the circuit to a variable voltage output but it still operates the
                same way. I posted this alternate circuit in the file sction.

                wilf


                --- In beam@yahoogroups.com, Chris McGuire <cmcguire@...> wrote:
                >
                > Hello Wilf,
                >
                > Yes, I've already made and given one. I just didn't have time
                to
                > work out the pulsing part of it, and had to place a mouser.com
                order,
                > which usually takes me a while.. I usually need so many little
                things
                > that I just compile a parts list, and buy at once. Otherwise, I
                would
                > have just used a MCU for it, and will for the first one. But for
                the
                > schematic you made, I will make a second one- I still have a few
                of
                > those lovely frosted blue 10mm LED's, and some 5mm amber ones I'd
                > like to get rid of. So, I think my newborn niece would like one
                wired
                > into a star for her. I'll wire that one parallel and use your
                > circuit, especially with the LDR, which is a fantastic touch.
                >
                > The wiring on the LED array is very simple. I cut a heart out
                of
                > paper, and made pencil marks where an LED will go. Then, I used a
                > tack to punch holes for the anode and cathode, and pushed the LED
                > through. Then, on the back, I made more marks to indicate the LED
                > groups, and the positive and negative sides. Then, I simply
                twisted
                > the right anodes & cathodes for each grouping together, added a
                > little solder.. I put the resistors on the negative side, slid a
                > little shrink-tubing on it, and soldered up wires to each side.
                Then,
                > using a dime-sized circular PCB from radio shack, I combined the
                > wires neatly. There was a single 1 ohm resistor used on each of
                the
                > groups of 3, and a 330 resistor used on the single LED. It's all
                > powered with a 9v battery, and works very well. I used the
                calculator
                > at http://led.linear1.org/1led.wiz to come up with the numbers for
                > everything. I also used liberal amounts of shrink-tube and tape to
                > prevent any shorts when I fastened it back onto the canvas.
                Luckily,
                > on the canvas I used ( http://www.dickblick.com/products/blick-
                studio-
                > gallery-profile-canvas/ ) has a little indentation on the top, so
                the
                > wiring fit nicely. Very simple project overall.
                >
                > And actually, may I ask for some advice? I am self-taught at
                > electronics. I've learned a lot, and I knew C going into this, but
                I
                > really need to learn numbers and the math behind everything. Do
                you
                > know of any online tutorials, or perhaps a college class or three
                I
                > can take? I'm seeking a degree in another field, but I want to get
                > good at this! But, my school is a trade school for mortuary science-

                > no fun electives there, just a good online degree for a guy who's
                > pushing 30 and needs to work (when there's work..)
                >
                > Thank you very much!
                >
                > Chris
                >
                > On Mar 1, 2009, at 8:16 PM, wilf_nv wrote:
                >
                >
                > >
                > > Hi Chris,
                > >
                > > My pleasure. Sounds like you already build one version. How did
                you
                > > wire the 4 groups of 3 plus 1 LEDs? How many resistors did you
                use?
                > >
                > > wilf
                > >
                > > --- In beam@yahoogroups.com, Chris McGuire <cmcguire@> wrote:
                > > >
                > > > Wow, thank you, Wilf!!
                > > >
                > > > That's way above and beyond.. I think I will have to make
                another
                > > > one! The first one I made is 4 groups of 3, with the extra
                hanging
                > > > out with a bigger resistor. But your design is so great,
                > > especially
                > > > with the LDR adding some interactivity to it- that's just
                > > brilliant!
                > > > I will certainly post a video of this one when it's done. Thank
                > > you
                > > > so much!
                > > >
                > > > Chris
                > > >
                > > >
                > > > On Mar 1, 2009, at 2:18 PM, wilf_nv wrote:
                > > >
                > > > > With some small mods the circuit should work fine for your
                > > > > application. I posted the schematic in the file section.
                > > > >
                > > > > By adding Q2 to drive Q1 a quasi darlington is created with
                high
                > > > > input resistance to decrease the loading of the capacitor
                node.
                > > With
                > > > > R2=33ohm, the LED current will be 130mA which can drive 13
                > > paralell
                > > > > LEDs to high brightenss. The LEDs should be from one batch and
                > > > > matched for equal brightness.
                > > > >
                > > > > Resistor R2 was put on the emitter of output transistor Q1 to
                make
                > > > > the driver a voltage controlled current source, less
                sensitive to
                > > > > power supply variations. Adjust R1 value or replace with 100K
                pot
                > > > > for frequency control. Adjust R2 value between 33 ohm and
                100ohm
                > > > > for brightness control.
                > > > >
                > > > > By adding a light dependent resistor (LDR nominal 10K in
                light)
                > > from
                > > > > 555 pin 5 to 0V, the LED brightness is decreased and off time
                is
                > > > > increased. When shaded by an onlooker, the heart grows
                brighter.
                > > > >
                > > > > wilf
                > > > >
                > > > > --- In beam@yahoogroups.com, Chris McGuire <cmcguire@> wrote:
                > > > > >
                > > > > > Thank you for looking at this! You're totally right, it
                isn't
                > > the
                > > > > > most elegant solution for what I'm doing. I really need all
                9v
                > > to
                > > > > be
                > > > > > handy, it's to be used on a 13 LED array. This circuit is
                just a
                > > > > > messy way of doing it. I think I'll be a lot happier with it
                > > when
                > > > > I
                > > > > > simply wait for the assortment of AVR chips I have on order
                to
                > > > > > arrive, and program the PWM to be exactly how I'll want it.
                > > > > >
                > > > > > Basically, what I've made, is a heart-shaped LED array, and
                I am
                > > > > > wanting it to pulse like a human's heartbeat. It's an
                upgrade
                > > to a
                > > > > > valentine's day gift I gave. I bought a small painting
                canvas,
                > > 4x4
                > > > > > inches, and removed the canvas from the frame, and wired my
                > > array
                > > > > > through it, after painting the canvas a solid matte black.
                The
                > > > > canvas
                > > > > > is about 1.5 inches deep, with a hole in the back- which
                works
                > > > > nicely
                > > > > > to hold the battery + a little extra space for a PCB+IC. I
                > > dremel'd
                > > > > a
                > > > > > little slot for the PCB and a larger one for the 9v
                battery, and
                > > > > made
                > > > > > a clean little lid for it with some balsa. Then, I re-
                assembled
                > > > > the
                > > > > > canvas, making it all nice and tight, so the LED's (mostly
                big
                > > > > 10mm
                > > > > > red and frosted blues) stand up straight. Then, for a
                switch, I
                > > > > took
                > > > > > a simple pressure switch, fastened it to the bottom back
                edge,
                > > and
                > > > > > got a wooden easel to set it on. When the frame is on the
                easel,
                > > > > it's
                > > > > > on, when it's off, it's off. Fits nice and works well.
                > > > > >
                > > > > > So, I think the best solution for this one is to do it
                right-
                > > I'll
                > > > > > take 4 or so of my own heart's pulse rates, make an average,
                > > then
                > > > > > program the AVR thusly. This would look much better than
                using a
                > > > > 555
                > > > > > for it. I'm just being impatient :)
                > > > > >
                > > > > > Thanks, all!
                > > > > >
                > > > > > Chris
                > > > > >
                > > > > >
                > > > > > On Feb 28, 2009, at 1:51 PM, wilf_nv wrote:
                > > > > >
                > > > > > >
                > > > > > >
                > > > > > > I asume the circuit is meant to alternately fade the LEDs
                on
                > > and
                > > > > then
                > > > > > > fade the LEDs off.
                > > > > > >
                > > > > > > I see how this would work but there is a missing
                connection
                > > that
                > > > > > > should connect 555 pin 2, pin 6 and the (+) side of the
                cap
                > > > > together
                > > > > > > and pin 7 must be left unconnected. This is why the
                circuit
                > > is not
                > > > > > > working.
                > > > > > >
                > > > > > > This 555 astable circuit was designed to generate a slow
                > > changing
                > > > > > > triangular voltage waveform at the base of the transistor
                > > which
                > > > > > > controls the current through the LEDs. The 100k resistor
                > > connected
                > > > > > > between the output pin 3 and the 100uf cap, discharges and
                > > charges
                > > > > > > the cap between 3V and 6v (with a 9V supply).
                > > > > > >
                > > > > > > Even when made fully fuctional, the LEDs are not very
                bright
                > > and
                > > > > the
                > > > > > > circuit is not an elegant solution for what it is
                supposed to
                > > do.
                > > > > > >
                > > > > > > I you have two 555 timers or a 556 dual timer you can
                make a
                > > much
                > > > > > > nicer design.
                > > > > > >
                > > > > > > wilf
                > > > > > >
                > > > > > > -- In beam@yahoogroups.com, Chris McGuire <cmcguire@>
                wrote:
                > > > > > > >
                > > > > > > > Oh, yeah! Duh. The only difference here, is that he's
                got 4
                > > > > LED's
                > > > > > > > down, and I'm trying to use this on a LED array, to make
                > > them
                > > > > all
                > > > > > > go
                > > > > > > > at once. Here it is..
                > > > > > > >
                > > > > > > > http://www.instructables.com/file/F4J70N0FRAAPMYY/
                > > > > > > >
                > > > > > > > Thanks!!
                > > > > > > >
                > > > > > > >
                > > > > > > > On Feb 28, 2009, at 12:18 PM, m3lt79 wrote:
                > > > > > > >
                > > > > > > > > It would help if you provide the schematic you are
                using.
                > > > > > > > >
                > > > > > > > > --- In beam@yahoogroups.com, Chris McGuire <cmcguire@>
                > > wrote:
                > > > > > > > > >
                > > > > > > > > > Hello all!
                > > > > > > > > >
                > > > > > > > > > I am looking for a way to use a 555 timer to fade a
                LED
                > > > > array
                > > > > > > in and
                > > > > > > > > > out, not blinky. I've found a schematic for it, but
                > > there's
                > > > > > > > > something
                > > > > > > > > > up with it- either I or it's is wrong. Does anyone
                have
                > > such
                > > > > > > info
                > > > > > > > > handy?
                > > > > > > > > >
                > > > > > > > > > Thank you!
                > > > > > > > > >
                > > > > > > > > > Chris
                > > > > > > > > >
                > > > > > > > >
                > > > > > > > >
                > > > > > > > >
                > > > > > > >
                > > > > > >
                > > > > > >
                > > > > > >
                > > > > >
                > > > >
                > > > >
                > > > >
                > > >
                > >
                > >
                > >
                >
              • Chris McGuire
                Yes, it s red and blue 10mm LED s. I ll keep this in mind for the future project! Thank you for the custom schematic.. that s super handy! I m going to have to
                Message 7 of 11 , Mar 2, 2009
                  Yes, it's red and blue 10mm LED's. I'll keep this in mind for the future project! Thank you for the custom schematic.. that's super handy! I'm going to have to order more LED's- I think I can get some great bulk deals from these guys: http://evilmadscience.com/partsmenu/89-led
                  I also find their minimal avr target boards make a great development kit for certain AVR's, too, plus, there's some great toys on there- meggy jr! DIY handheld gaming. 

                  Anyhow! Off to picking out LED's for me- those 200 cheap blue LEDs for 16 bucks sounds too good to refuse. I can build a huge array with a couple of those, just punch them through some black corkboard & figure out how to put Conway's game of life on there- that would make a swanky wall hanging, no?\

                  Thanks, Wilf!! 


                  On Mar 2, 2009, at 12:52 AM, wilf_nv wrote:

                  I mentioned matching LEDs but it sounds like you may be using a 
                  variety of LEDs in different groups. For better control of each LED 
                  brightness use individual series resistors for each LED and then wire 
                  these LED/resistor pairs all in parallel. That requires a change in 
                  the circuit to a variable voltage output but it still operates the 
                  same way. I posted this alternate circuit in the file sction.

                  wilf 

                  --- In beam@yahoogroups. com, Chris McGuire <cmcguire@.. .> wrote:
                  >
                  > Hello Wilf,
                  > 
                  > Yes, I've already made and given one. I just didn't have time 
                  to 
                  > work out the pulsing part of it, and had to place a mouser.com 
                  order, 
                  > which usually takes me a while.. I usually need so many little 
                  things 
                  > that I just compile a parts list, and buy at once. Otherwise, I 
                  would 
                  > have just used a MCU for it, and will for the first one. But for 
                  the 
                  > schematic you made, I will make a second one- I still have a few 
                  of 
                  > those lovely frosted blue 10mm LED's, and some 5mm amber ones I'd 
                  > like to get rid of. So, I think my newborn niece would like one 
                  wired 
                  > into a star for her. I'll wire that one parallel and use your 
                  > circuit, especially with the LDR, which is a fantastic touch.
                  > 
                  > The wiring on the LED array is very simple. I cut a heart out 
                  of 
                  > paper, and made pencil marks where an LED will go. Then, I used a 
                  > tack to punch holes for the anode and cathode, and pushed the LED 
                  > through. Then, on the back, I made more marks to indicate the LED 
                  > groups, and the positive and negative sides. Then, I simply 
                  twisted 
                  > the right anodes & cathodes for each grouping together, added a 
                  > little solder.. I put the resistors on the negative side, slid a 
                  > little shrink-tubing on it, and soldered up wires to each side. 
                  Then, 
                  > using a dime-sized circular PCB from radio shack, I combined the 
                  > wires neatly. There was a single 1 ohm resistor used on each of 
                  the 
                  > groups of 3, and a 330 resistor used on the single LED. It's all 
                  > powered with a 9v battery, and works very well. I used the 
                  calculator 
                  > at http://led.linear1. org/1led. wiz to come up with the numbers for 
                  > everything. I also used liberal amounts of shrink-tube and tape to 
                  > prevent any shorts when I fastened it back onto the canvas. 
                  Luckily, 
                  > on the canvas I used ( http://www.dickblic k.com/products/ blick-
                  studio- 
                  > gallery-profile- canvas/ ) has a little indentation on the top, so 
                  the 
                  > wiring fit nicely. Very simple project overall.
                  > 
                  > And actually, may I ask for some advice? I am self-taught at 
                  > electronics. I've learned a lot, and I knew C going into this, but 
                  I 
                  > really need to learn numbers and the math behind everything. Do 
                  you 
                  > know of any online tutorials, or perhaps a college class or three 
                  I 
                  > can take? I'm seeking a degree in another field, but I want to get 
                  > good at this! But, my school is a trade school for mortuary science-

                  > no fun electives there, just a good online degree for a guy who's 
                  > pushing 30 and needs to work (when there's work..)
                  > 
                  > Thank you very much!
                  > 
                  > Chris
                  > 
                  > On Mar 1, 2009, at 8:16 PM, wilf_nv wrote:
                  > 
                  > 
                  > >
                  > > Hi Chris,
                  > >
                  > > My pleasure. Sounds like you already build one version. How did 
                  you
                  > > wire the 4 groups of 3 plus 1 LEDs? How many resistors did you 
                  use?
                  > >
                  > > wilf
                  > >
                  > > --- In beam@yahoogroups. com, Chris McGuire <cmcguire@> wrote:
                  > > >
                  > > > Wow, thank you, Wilf!!
                  > > >
                  > > > That's way above and beyond.. I think I will have to make 
                  another
                  > > > one! The first one I made is 4 groups of 3, with the extra 
                  hanging
                  > > > out with a bigger resistor. But your design is so great,
                  > > especially
                  > > > with the LDR adding some interactivity to it- that's just
                  > > brilliant!
                  > > > I will certainly post a video of this one when it's done. Thank
                  > > you
                  > > > so much!
                  > > >
                  > > > Chris
                  > > >
                  > > >
                  > > > On Mar 1, 2009, at 2:18 PM, wilf_nv wrote:
                  > > >
                  > > > > With some small mods the circuit should work fine for your
                  > > > > application. I posted the schematic in the file section.
                  > > > >
                  > > > > By adding Q2 to drive Q1 a quasi darlington is created with 
                  high
                  > > > > input resistance to decrease the loading of the capacitor 
                  node.
                  > > With
                  > > > > R2=33ohm, the LED current will be 130mA which can drive 13
                  > > paralell
                  > > > > LEDs to high brightenss. The LEDs should be from one batch and
                  > > > > matched for equal brightness.
                  > > > >
                  > > > > Resistor R2 was put on the emitter of output transistor Q1 to 
                  make
                  > > > > the driver a voltage controlled current source, less 
                  sensitive to
                  > > > > power supply variations. Adjust R1 value or replace with 100K 
                  pot
                  > > > > for frequency control. Adjust R2 value between 33 ohm and 
                  100ohm
                  > > > > for brightness control.
                  > > > >
                  > > > > By adding a light dependent resistor (LDR nominal 10K in 
                  light)
                  > > from
                  > > > > 555 pin 5 to 0V, the LED brightness is decreased and off time 
                  is
                  > > > > increased. When shaded by an onlooker, the heart grows 
                  brighter.
                  > > > >
                  > > > > wilf
                  > > > >
                  > > > > --- In beam@yahoogroups. com, Chris McGuire <cmcguire@> wrote:
                  > > > > >
                  > > > > > Thank you for looking at this! You're totally right, it 
                  isn't
                  > > the
                  > > > > > most elegant solution for what I'm doing. I really need all 
                  9v
                  > > to
                  > > > > be
                  > > > > > handy, it's to be used on a 13 LED array. This circuit is 
                  just a
                  > > > > > messy way of doing it. I think I'll be a lot happier with it
                  > > when
                  > > > > I
                  > > > > > simply wait for the assortment of AVR chips I have on order 
                  to
                  > > > > > arrive, and program the PWM to be exactly how I'll want it.
                  > > > > >
                  > > > > > Basically, what I've made, is a heart-shaped LED array, and 
                  I am
                  > > > > > wanting it to pulse like a human's heartbeat. It's an 
                  upgrade
                  > > to a
                  > > > > > valentine's day gift I gave. I bought a small painting 
                  canvas,
                  > > 4x4
                  > > > > > inches, and removed the canvas from the frame, and wired my
                  > > array
                  > > > > > through it, after painting the canvas a solid matte black. 
                  The
                  > > > > canvas
                  > > > > > is about 1.5 inches deep, with a hole in the back- which 
                  works
                  > > > > nicely
                  > > > > > to hold the battery + a little extra space for a PCB+IC. I
                  > > dremel'd
                  > > > > a
                  > > > > > little slot for the PCB and a larger one for the 9v 
                  battery, and
                  > > > > made
                  > > > > > a clean little lid for it with some balsa. Then, I re-
                  assembled
                  > > > > the
                  > > > > > canvas, making it all nice and tight, so the LED's (mostly 
                  big
                  > > > > 10mm
                  > > > > > red and frosted blues) stand up straight. Then, for a 
                  switch, I
                  > > > > took
                  > > > > > a simple pressure switch, fastened it to the bottom back 
                  edge,
                  > > and
                  > > > > > got a wooden easel to set it on. When the frame is on the 
                  easel,
                  > > > > it's
                  > > > > > on, when it's off, it's off. Fits nice and works well.
                  > > > > >
                  > > > > > So, I think the best solution for this one is to do it 
                  right-
                  > > I'll
                  > > > > > take 4 or so of my own heart's pulse rates, make an average,
                  > > then
                  > > > > > program the AVR thusly. This would look much better than 
                  using a
                  > > > > 555
                  > > > > > for it. I'm just being impatient :)
                  > > > > >
                  > > > > > Thanks, all!
                  > > > > >
                  > > > > > Chris
                  > > > > >
                  > > > > >
                  > > > > > On Feb 28, 2009, at 1:51 PM, wilf_nv wrote:
                  > > > > >
                  > > > > > >
                  > > > > > >
                  > > > > > > I asume the circuit is meant to alternately fade the LEDs 
                  on
                  > > and
                  > > > > then
                  > > > > > > fade the LEDs off.
                  > > > > > >
                  > > > > > > I see how this would work but there is a missing 
                  connection
                  > > that
                  > > > > > > should connect 555 pin 2, pin 6 and the (+) side of the 
                  cap
                  > > > > together
                  > > > > > > and pin 7 must be left unconnected. This is why the 
                  circuit
                  > > is not
                  > > > > > > working.
                  > > > > > >
                  > > > > > > This 555 astable circuit was designed to generate a slow
                  > > changing
                  > > > > > > triangular voltage waveform at the base of the transistor
                  > > which
                  > > > > > > controls the current through the LEDs. The 100k resistor
                  > > connected
                  > > > > > > between the output pin 3 and the 100uf cap, discharges and
                  > > charges
                  > > > > > > the cap between 3V and 6v (with a 9V supply).
                  > > > > > >
                  > > > > > > Even when made fully fuctional, the LEDs are not very 
                  bright
                  > > and
                  > > > > the
                  > > > > > > circuit is not an elegant solution for what it is 
                  supposed to
                  > > do.
                  > > > > > >
                  > > > > > > I you have two 555 timers or a 556 dual timer you can 
                  make a
                  > > much
                  > > > > > > nicer design.
                  > > > > > >
                  > > > > > > wilf
                  > > > > > >
                  > > > > > > -- In beam@yahoogroups. com, Chris McGuire <cmcguire@> 
                  wrote:
                  > > > > > > >
                  > > > > > > > Oh, yeah! Duh. The only difference here, is that he's 
                  got 4
                  > > > > LED's
                  > > > > > > > down, and I'm trying to use this on a LED array, to make
                  > > them
                  > > > > all
                  > > > > > > go
                  > > > > > > > at once. Here it is..
                  > > > > > > >
                  > > > > > > > http://www.instruct ables.com/ file/F4J70N0FRAA PMYY/
                  > > > > > > >
                  > > > > > > > Thanks!!
                  > > > > > > >
                  > > > > > > >
                  > > > > > > > On Feb 28, 2009, at 12:18 PM, m3lt79 wrote:
                  > > > > > > >
                  > > > > > > > > It would help if you provide the schematic you are 
                  using.
                  > > > > > > > >
                  > > > > > > > > --- In beam@yahoogroups. com, Chris McGuire <cmcguire@>
                  > > wrote:
                  > > > > > > > > >
                  > > > > > > > > > Hello all!
                  > > > > > > > > >
                  > > > > > > > > > I am looking for a way to use a 555 timer to fade a 
                  LED
                  > > > > array
                  > > > > > > in and
                  > > > > > > > > > out, not blinky. I've found a schematic for it, but
                  > > there's
                  > > > > > > > > something
                  > > > > > > > > > up with it- either I or it's is wrong. Does anyone 
                  have
                  > > such
                  > > > > > > info
                  > > > > > > > > handy?
                  > > > > > > > > >
                  > > > > > > > > > Thank you!
                  > > > > > > > > >
                  > > > > > > > > > Chris
                  > > > > > > > > >
                  > > > > > > > >
                  > > > > > > > >
                  > > > > > > > >
                  > > > > > > >
                  > > > > > >
                  > > > > > >
                  > > > > > >
                  > > > > >
                  > > > >
                  > > > >
                  > > > >
                  > > >
                  > >
                  > >
                  > >
                  >


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