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Using Photoflasher... "Rovore"...coming this year!

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  • Harold
    Hi group! I m just wondering, maybe we could use a photoflash/er from a disposable camera, to make a photovore or some sort. My idea is to attach a solar cell
    Message 1 of 12 , Jul 1, 2006
      Hi group! I'm just wondering, maybe we could use a photoflash/er
      from a disposable camera, to make a photovore or some sort. My idea
      is to attach a solar cell and a little modification on the circuit
      to make it phototropic orphotophobic. And maybe that's it! We could
      have a nice little bot that charges it's capacitor by the solar cell
      and dumps more power to a load, like a motor. Also, instead of a
      normal switch from the photoflash, we could use some sort of a
      switching method. What do you think Sir Wilf?

      I thought about this idea for quite some time. Maybe this is the
      time to work this out and a little help from you guys.

      And by the way, I'm working on my next bot and I got its name
      already, "Ro-vore" or "Rovore" or "Mars Rovore". It will be a BEAM
      photovore that seeks out any source of light especially the sun or a
      high wattage light bulb which will stop on the spot and charges its
      batteries or a capacitor for a few minutes then off it goes to
      wander around. Well, that's just a plan and hopefully it would be
      easy or possible for me to work with. I like challenges! Happy
      BEAMing everyone! ;)

      ....Harold.
    • Harold
      Well, think of it.... the photoflasher I m experimenting with, uses a 1F cap. When you apply power to it and switch it ON, a small light bulb lights up which
      Message 2 of 12 , Jul 3, 2006
        Well, think of it.... the photoflasher I'm experimenting with, uses
        a 1F cap. When you apply power to it and switch it ON, a small light
        bulb lights up which means it's time to trigger the switch, to make
        a quick flash, just like taking pics. The point is, if we could use
        this thing to charge up a capacitor that fast. The cap will be
        charged within 3 to 4 secs when you switch it ON. :)

        Well, it's nice thing to experiment with isn't it? The circuit is
        very small and uses just 3 volts or could be a solar cell or even a
        solar engine. Go and find one in your junk box and have fun. But
        remember, don't touch some components/parts in the circuit, you can
        be electricuted because of its high voltage/small transformer. Small
        is terrible! Be cautious and wear plastic or non conductive gloves
        whatsoever. Just a reminder. Take care and goodluck to all! Have fun
        guys! :D

        ...Harold.


        --- In beam@yahoogroups.com, "Harold" <harold.ilano@...> wrote:
        >
        > Hi group! I'm just wondering, maybe we could use a photoflash/er
        > from a disposable camera, to make a photovore or some sort. My
        idea
        > is to attach a solar cell and a little modification on the circuit
        > to make it phototropic orphotophobic. And maybe that's it! We
        could
        > have a nice little bot that charges it's capacitor by the solar
        cell
        > and dumps more power to a load, like a motor. Also, instead of a
        > normal switch from the photoflash, we could use some sort of a
        > switching method. What do you think Sir Wilf?
        >
        > I thought about this idea for quite some time. Maybe this is the
        > time to work this out and a little help from you guys.
        >
        > And by the way, I'm working on my next bot and I got its name
        > already, "Ro-vore" or "Rovore" or "Mars Rovore". It will be a BEAM
        > photovore that seeks out any source of light especially the sun or
        a
        > high wattage light bulb which will stop on the spot and charges
        its
        > batteries or a capacitor for a few minutes then off it goes to
        > wander around. Well, that's just a plan and hopefully it would be
        > easy or possible for me to work with. I like challenges! Happy
        > BEAMing everyone! ;)
        >
        > ....Harold.
        >
      • Harold
        Well, think of it.... the photoflasher I m experimenting with, uses a 1F cap. When you apply power to it and switch it ON, a small light bulb lights up which
        Message 3 of 12 , Jul 3, 2006
          Well, think of it.... the photoflasher I'm experimenting with, uses
          a 1F cap. When you apply power to it and switch it ON, a small light
          bulb lights up which means it's time to trigger the switch, to make
          a quick flash, just like taking pics. The point is, if we could use
          this thing to charge up a capacitor that fast. The cap will be
          charged within 3 to 4 secs when you switch it ON. :)

          Well, it's nice thing to experiment with isn't it? The circuit is
          very small and uses just 3 volts or could be a solar cell or even a
          solar engine. Go and find one in your junk box and have fun. But
          remember, don't touch some components/parts in the circuit, you can
          be electricuted because of its high voltage/small transformer. Small
          is terrible! Be cautious and wear plastic or non conductive gloves
          whatsoever. Just a reminder. Take care and goodluck to all! Have fun
          guys! :D

          ...Harold.


          --- In beam@yahoogroups.com, "Harold" <harold.ilano@...> wrote:
          >
          > Hi group! I'm just wondering, maybe we could use a photoflash/er
          > from a disposable camera, to make a photovore or some sort. My
          idea
          > is to attach a solar cell and a little modification on the circuit
          > to make it phototropic orphotophobic. And maybe that's it! We
          could
          > have a nice little bot that charges it's capacitor by the solar
          cell
          > and dumps more power to a load, like a motor. Also, instead of a
          > normal switch from the photoflash, we could use some sort of a
          > switching method. What do you think Sir Wilf?
          >
          > I thought about this idea for quite some time. Maybe this is the
          > time to work this out and a little help from you guys.
          >
          > And by the way, I'm working on my next bot and I got its name
          > already, "Ro-vore" or "Rovore" or "Mars Rovore". It will be a BEAM
          > photovore that seeks out any source of light especially the sun or
          a
          > high wattage light bulb which will stop on the spot and charges
          its
          > batteries or a capacitor for a few minutes then off it goes to
          > wander around. Well, that's just a plan and hopefully it would be
          > easy or possible for me to work with. I like challenges! Happy
          > BEAMing everyone! ;)
          >
          > ....Harold.
          >
        • Harold
          Well, think of it.... the photoflasher I m experimenting with, uses a 1F cap. When you apply power to it and switch it ON, a small light bulb lights up which
          Message 4 of 12 , Jul 3, 2006
            Well, think of it.... the photoflasher I'm experimenting with, uses
            a 1F cap. When you apply power to it and switch it ON, a small light
            bulb lights up which means it's time to trigger the switch, to make
            a quick flash, just like taking pics. The point is, if we could use
            this thing to charge up a capacitor that fast. The cap will be
            charged within 3 to 4 secs when you switch it ON. :)

            Well, it's nice thing to experiment with isn't it? The circuit is
            very small and uses just 3 volts or could be a solar cell or even a
            solar engine. Go and find one in your junk box and have fun. But
            remember, don't touch some components/parts in the circuit, you can
            be electricuted because of its high voltage/small transformer. Small
            is terrible! Be cautious and wear plastic or non conductive gloves
            whatsoever. Just a reminder. Take care and goodluck to all! Have fun
            guys! :D

            ...Harold.


            --- In beam@yahoogroups.com, "Harold" <harold.ilano@...> wrote:
            >
            > Hi group! I'm just wondering, maybe we could use a photoflash/er
            > from a disposable camera, to make a photovore or some sort. My
            idea
            > is to attach a solar cell and a little modification on the circuit
            > to make it phototropic orphotophobic. And maybe that's it! We
            could
            > have a nice little bot that charges it's capacitor by the solar
            cell
            > and dumps more power to a load, like a motor. Also, instead of a
            > normal switch from the photoflash, we could use some sort of a
            > switching method. What do you think Sir Wilf?
            >
            > I thought about this idea for quite some time. Maybe this is the
            > time to work this out and a little help from you guys.
            >
            > And by the way, I'm working on my next bot and I got its name
            > already, "Ro-vore" or "Rovore" or "Mars Rovore". It will be a BEAM
            > photovore that seeks out any source of light especially the sun or
            a
            > high wattage light bulb which will stop on the spot and charges
            its
            > batteries or a capacitor for a few minutes then off it goes to
            > wander around. Well, that's just a plan and hopefully it would be
            > easy or possible for me to work with. I like challenges! Happy
            > BEAMing everyone! ;)
            >
            > ....Harold.
            >
          • wilf
            Remember that the flash unit charges the 100uF high voltage capacitor up to 300V. Since the energy is 0.5C x V xV, that is a lot of stored energy which can
            Message 5 of 12 , Jul 3, 2006
              Remember that the flash unit charges the 100uF high voltage capacitor up to 300V. Since the energy is 0.5C x V xV, that is a lot of stored energy which can hurt you, weld metal, start a fire, etc.
               
              It would also be good to zap bugs!
               
              The reason the neon light comes on so quick is that the 3V battery supplies several amps of current.  So you need to have some heavy duty storage eg a 1F / 5V  cap for one or two flashes or a rechargable battery to run at night. 
               
              Use it like a nocturnal pummer or if used as a bug triggered flasher (add a motion detector?)
               
              Anyway,  projects using high voltage are for experienced builders who know how to take the necesary safety precautions.
               
              enjoy   
               
              wilf
               
               
              ----- Original Message -----
              From: Harold
              Sent: Monday, July 03, 2006 7:08 AM
              Subject: [beam] Re: Using Photoflasher... "Rovore"...coming this year!

              Well, think of it.... the photoflasher I'm experimenting with, uses
              a 1F cap. When you apply power to it and switch it ON, a small light
              bulb lights up which means it's time to trigger the switch, to make
              a quick flash, just like taking pics. The point is, if we could use
              this thing to charge up a capacitor that fast. The cap will be
              charged within 3 to 4 secs when you switch it ON. :)

              Well, it's nice thing to experiment with isn't it? The circuit is
              very small and uses just 3 volts or could be a solar cell or even a
              solar engine. Go and find one in your junk box and have fun. But
              remember, don't touch some components/parts in the circuit, you can
              be electricuted because of its high voltage/small transformer. Small
              is terrible! Be cautious and wear plastic or non conductive gloves
              whatsoever. Just a reminder. Take care and goodluck to all! Have fun
              guys! :D

              ...Harold.

              --- In beam@yahoogroups. com, "Harold" <harold.ilano@ ...> wrote:
              >
              > Hi group! I'm just wondering, maybe we could use a photoflash/er
              > from a disposable camera, to make a photovore or some sort. My
              idea
              > is to attach a solar cell and a little modification on the circuit
              > to make it phototropic orphotophobic. And maybe that's it! We
              could
              > have a nice little bot that charges it's capacitor by the solar
              cell
              > and dumps more power to a load, like a motor. Also, instead of a
              > normal switch from the photoflash, we could use some sort of a
              > switching method. What do you think Sir Wilf?
              >
              > I thought about this idea for quite some time. Maybe this is the
              > time to work this out and a little help from you guys.
              >
              > And by the way, I'm working on my next bot and I got its name
              > already, "Ro-vore" or "Rovore" or "Mars Rovore". It will be a BEAM
              > photovore that seeks out any source of light especially the sun or
              a
              > high wattage light bulb which will stop on the spot and charges
              its
              > batteries or a capacitor for a few minutes then off it goes to
              > wander around. Well, that's just a plan and hopefully it would be
              > easy or possible for me to work with. I like challenges! Happy
              > BEAMing everyone! ;)
              >
              > ....Harold.
              >

            • Harold
              Hi Wilf, thanks for the reply! Yeah, you re absolutely right. Well, my cap (in the photoflasher) indicates that it s a 1F cap but no voltage labeled. I ll
              Message 6 of 12 , Jul 3, 2006
                Hi Wilf, thanks for the reply! Yeah, you're absolutely right. Well,
                my cap (in the photoflasher) indicates that it's a "1F" cap but no
                voltage labeled. I'll have to check the voltage reading first on my
                multimeter. Safety precautions is mandatory with this thing. ;)

                Bug zapper was also what I thought about. I've also built 2 years
                ago, a jacob's ladder, which is also an interesting project. I guess
                I have to make a page for that one day. The spark gap is about an
                inch, but if i put it in a sealed container, it may reach up to 2
                inches. No air should be present during the process to achieve good
                results. Quite cool though! :)

                Anyways, I'm still thinking of the best of use with this
                photoflasher. I'm just interested in the fast charging process of
                the capacitor. I'm also collecting circuits of phtot sensors, just
                like what you've said...motion sensors or even a shadow sensor.
                Still planning and documenting the idea. I'll keep in touch though.
                Thanks again Wilf and 'hope to hear more comments or topic for this
                little (and shocking) project. Take care.

                ...Harold.



                --- In beam@yahoogroups.com, "wilf" <wrigter@...> wrote:
                >
                > Remember that the flash unit charges the 100uF high voltage
                capacitor up to 300V. Since the energy is 0.5C x V xV, that is a lot
                of stored energy which can hurt you, weld metal, start a fire, etc.
                >
                > It would also be good to zap bugs!
                >
                > The reason the neon light comes on so quick is that the 3V battery
                supplies several amps of current. So you need to have some heavy
                duty storage eg a 1F / 5V cap for one or two flashes or a
                rechargable battery to run at night.
                >
                > Use it like a nocturnal pummer or if used as a bug triggered
                flasher (add a motion detector?)
                >
                > Anyway, projects using high voltage are for experienced builders
                who know how to take the necesary safety precautions.
                >
                > enjoy
                >
                > wilf
                >
                >
                > ----- Original Message -----
                > From: Harold
                > To: beam@yahoogroups.com
                > Sent: Monday, July 03, 2006 7:08 AM
                > Subject: [beam] Re: Using Photoflasher... "Rovore"...coming this
                year!
                >
                >
                > Well, think of it.... the photoflasher I'm experimenting with,
                uses
                > a 1F cap. When you apply power to it and switch it ON, a small
                light
                > bulb lights up which means it's time to trigger the switch, to
                make
                > a quick flash, just like taking pics. The point is, if we could
                use
                > this thing to charge up a capacitor that fast. The cap will be
                > charged within 3 to 4 secs when you switch it ON. :)
                >
                > Well, it's nice thing to experiment with isn't it? The circuit
                is
                > very small and uses just 3 volts or could be a solar cell or
                even a
                > solar engine. Go and find one in your junk box and have fun. But
                > remember, don't touch some components/parts in the circuit, you
                can
                > be electricuted because of its high voltage/small transformer.
                Small
                > is terrible! Be cautious and wear plastic or non conductive
                gloves
                > whatsoever. Just a reminder. Take care and goodluck to all! Have
                fun
                > guys! :D
                >
                > ...Harold.
                >
                > --- In beam@yahoogroups.com, "Harold" <harold.ilano@> wrote:
                > >
                > > Hi group! I'm just wondering, maybe we could use a
                photoflash/er
                > > from a disposable camera, to make a photovore or some sort. My
                > idea
                > > is to attach a solar cell and a little modification on the
                circuit
                > > to make it phototropic orphotophobic. And maybe that's it! We
                > could
                > > have a nice little bot that charges it's capacitor by the
                solar
                > cell
                > > and dumps more power to a load, like a motor. Also, instead of
                a
                > > normal switch from the photoflash, we could use some sort of a
                > > switching method. What do you think Sir Wilf?
                > >
                > > I thought about this idea for quite some time. Maybe this is
                the
                > > time to work this out and a little help from you guys.
                > >
                > > And by the way, I'm working on my next bot and I got its name
                > > already, "Ro-vore" or "Rovore" or "Mars Rovore". It will be a
                BEAM
                > > photovore that seeks out any source of light especially the
                sun or
                > a
                > > high wattage light bulb which will stop on the spot and
                charges
                > its
                > > batteries or a capacitor for a few minutes then off it goes to
                > > wander around. Well, that's just a plan and hopefully it would
                be
                > > easy or possible for me to work with. I like challenges! Happy
                > > BEAMing everyone! ;)
                > >
                > > ....Harold.
                > >
                >
              • Harold
                Hello again Wilf! Oops, I was wrong. The cap in my photoflasher says 160uF 330V. I didn t notice, hehehe! My bad. :) Well, it s my free time today, I should do
                Message 7 of 12 , Jul 3, 2006
                  Hello again Wilf!

                  Oops, I was wrong. The cap in my photoflasher says 160uF 330V. I
                  didn't notice, hehehe! My bad. :)

                  Well, it's my free time today, I should do something about it
                  anyhow. Thanks again Wilf and more power! ;)

                  ...Harold.



                  --- In beam@yahoogroups.com, "wilf" <wrigter@...> wrote:
                  >
                  > Remember that the flash unit charges the 100uF high voltage
                  capacitor up to 300V. Since the energy is 0.5C x V xV, that is a lot
                  of stored energy which can hurt you, weld metal, start a fire, etc.
                  >
                  > It would also be good to zap bugs!
                  >
                  > The reason the neon light comes on so quick is that the 3V battery
                  supplies several amps of current. So you need to have some heavy
                  duty storage eg a 1F / 5V cap for one or two flashes or a
                  rechargable battery to run at night.
                  >
                  > Use it like a nocturnal pummer or if used as a bug triggered
                  flasher (add a motion detector?)
                  >
                  > Anyway, projects using high voltage are for experienced builders
                  who know how to take the necesary safety precautions.
                  >
                  > enjoy
                  >
                  > wilf
                  >
                  >
                  > ----- Original Message -----
                  > From: Harold
                  > To: beam@yahoogroups.com
                  > Sent: Monday, July 03, 2006 7:08 AM
                  > Subject: [beam] Re: Using Photoflasher... "Rovore"...coming this
                  year!
                  >
                  >
                  > Well, think of it.... the photoflasher I'm experimenting with,
                  uses
                  > a 1F cap. When you apply power to it and switch it ON, a small
                  light
                  > bulb lights up which means it's time to trigger the switch, to
                  make
                  > a quick flash, just like taking pics. The point is, if we could
                  use
                  > this thing to charge up a capacitor that fast. The cap will be
                  > charged within 3 to 4 secs when you switch it ON. :)
                  >
                  > Well, it's nice thing to experiment with isn't it? The circuit
                  is
                  > very small and uses just 3 volts or could be a solar cell or
                  even a
                  > solar engine. Go and find one in your junk box and have fun. But
                  > remember, don't touch some components/parts in the circuit, you
                  can
                  > be electricuted because of its high voltage/small transformer.
                  Small
                  > is terrible! Be cautious and wear plastic or non conductive
                  gloves
                  > whatsoever. Just a reminder. Take care and goodluck to all! Have
                  fun
                  > guys! :D
                  >
                  > ...Harold.
                  >
                  > --- In beam@yahoogroups.com, "Harold" <harold.ilano@> wrote:
                  > >
                  > > Hi group! I'm just wondering, maybe we could use a
                  photoflash/er
                  > > from a disposable camera, to make a photovore or some sort. My
                  > idea
                  > > is to attach a solar cell and a little modification on the
                  circuit
                  > > to make it phototropic orphotophobic. And maybe that's it! We
                  > could
                  > > have a nice little bot that charges it's capacitor by the
                  solar
                  > cell
                  > > and dumps more power to a load, like a motor. Also, instead of
                  a
                  > > normal switch from the photoflash, we could use some sort of a
                  > > switching method. What do you think Sir Wilf?
                  > >
                  > > I thought about this idea for quite some time. Maybe this is
                  the
                  > > time to work this out and a little help from you guys.
                  > >
                  > > And by the way, I'm working on my next bot and I got its name
                  > > already, "Ro-vore" or "Rovore" or "Mars Rovore". It will be a
                  BEAM
                  > > photovore that seeks out any source of light especially the
                  sun or
                  > a
                  > > high wattage light bulb which will stop on the spot and
                  charges
                  > its
                  > > batteries or a capacitor for a few minutes then off it goes to
                  > > wander around. Well, that's just a plan and hopefully it would
                  be
                  > > easy or possible for me to work with. I like challenges! Happy
                  > > BEAMing everyone! ;)
                  > >
                  > > ....Harold.
                  > >
                  >
                • chrisvaughan02
                  ... supplies several amps of current. So you need to have some heavy duty storage eg a 1F / 5V cap for one or two flashes or a rechargable battery to run at
                  Message 8 of 12 , Jul 3, 2006
                    --- In beam@yahoogroups.com, "wilf" <wrigter@...> wrote:
                    > The reason the neon light comes on so quick is that the 3V battery
                    supplies several amps of current. So you need to have some heavy duty
                    storage eg a 1F / 5V cap for one or two flashes or a rechargable
                    battery to run at night.

                    Wilf,

                    Just curious, how can a 3v batterry charge a cap to 300v? when the cap
                    reaches 3v how does it continue to accept voltage from a 3v source.
                    seems like anything over 3v would treat the 3v batterry as a ground. I
                    could be wrong, I'm still very new, and this may be a stupid question
                    but you never learn if you dont ask.

                    God Bless,
                    Chris
                  • Damian Stewart
                    ... as i understood it this was just how photopoppers work - you pour charge into a large capacitor and once it hits a certain voltage (significantly higher
                    Message 9 of 12 , Jul 3, 2006
                      chrisvaughan02 wrote:
                      > Just curious, how can a 3v batterry charge a cap to 300v? when the cap
                      > reaches 3v how does it continue to accept voltage from a 3v source.
                      > seems like anything over 3v would treat the 3v batterry as a ground. I
                      > could be wrong, I'm still very new, and this may be a stupid question
                      > but you never learn if you dont ask.

                      as i understood it this was just how photopoppers work - you pour charge
                      into a large capacitor and once it hits a certain voltage (significantly
                      higher than your solar panel is putting out), something else (like a FLED,
                      which as I understand it take quite a high voltage to trigger) opens up and
                      so allows your capacitor to discharge.

                      i could be very wrong, i'm still learning this electronics malarky myself :-)

                      --
                      f r e y
                      live music with computers
                      http://www.frey.co.nz
                    • WilliamChops Westfield
                      ... A typical photoflash takes about 5 to 10s to charge up the 100uF cap to 300V or so from 3V. One reason some flash units seem to charge the cap quickly
                      Message 10 of 12 , Jul 4, 2006
                        On Jul 3, 2006, at 3:40 PM, Harold wrote:

                        > I'm just interested in the fast charging process of the capacitor.

                        A "typical" photoflash takes about 5 to 10s to charge up the
                        100uF cap to 300V or so from 3V. One reason some flash units
                        seem to charge the cap quickly is that they never discharged
                        it from the last time the camera was on, so the cap still has
                        a partial charge...

                        BillW
                      • wilf
                        Good question Chris! The photoflash works similarly to an car ignition system which uses a ignition coil (transformer) with a 12V primary winding and a high
                        Message 11 of 12 , Jul 4, 2006
                          Good question Chris!
                           
                          The photoflash works similarly to an car ignition system which uses a ignition coil (transformer) with a 12V primary winding and a high voltage secondary winding to generate a 20,000V spark.
                           
                          The photoflash circuit generates 300V pulses and then uses a rectifier to charge the high voltage cap from these high voltage pulses. 
                           
                          One type circuit that can convert a  3V source to a high voltage pulse works as follows:
                           
                          1. Turn on a transistor which switches to ground one side of an inductor, connected on the other side to the  3V source.
                           
                          2. This allows current to build up in the inductor winding, which stores energy in an increasingly intense magnetic field.
                           
                          3. When the current reaches a preset value, rapidly switch off the transistor.
                           
                          4. The collapsing magnetic field holds up the current by rapidly driving the transistor collector voltage positive up to >300V. (This requires the use of a high volatge transistor)
                           
                          5. When the rising  voltage on the transistor collector is slightly higher than the voltage on the high voltage capcitor, the rectifier turns on and the current from the inductor is discharged into the capacitor. 
                           
                          6. Each high voltage pulse is rectified and increases the voltage on the cap by a small step. For example, if the initial voltage on the capacitor is 2.4V (the battery voltage minus a diode drop), then the collector voltage rises only to about 4V for the first pulse, then to 5V for the second pulse then to 6V for the next pulse and so on.     
                           
                          7. A voltage sensor (neon bulb) turns on when the voltage reaches 300V and the current through the neon bulb is used to shut of the high voltage capacitor charging circuit.
                           
                          8. When the flash is fired, the high voltage cap is discharged through a flash lamp filled with Xenon/Krypton/Argon gases which produces an intense white light..
                           
                          9. When the high voltage cap voltage drops below the neon bulb turnoff voltage ( <200V), the HV charging circuit starts switching again and the charge cyle repeats.
                           
                          More popular photo flash circuits use this circuit with a transformer instead of an inductor. The low voltage winding uses a few turns or wire on the magnetic core, The high voltage winding uses many turns on the same core. That way the voltage pulse on the low voltage side of the transformer is multiplied by the turns ratio (typically 1:30). This allows the use of low voltage switching transistor since the voltage on the collector on the low voltage winding may rise to 10V while the high voltage winding voltage rises to >300V to charge the cap.
                           
                          Hope that description helps answer your question.
                           
                          wilf  
                           
                          ----- Original Message -----
                          Sent: Monday, July 03, 2006 7:18 PM
                          Subject: [beam] Re: Using Photoflasher... "Rovore"...coming this year! - THIS IS OFF TOPIC!

                          --- In beam@yahoogroups. com, "wilf" <wrigter@... > wrote:
                          > The reason the neon light comes on so quick is that the 3V battery
                          supplies several amps of current. So you need to have some heavy duty
                          storage eg a 1F / 5V cap for one or two flashes or a rechargable
                          battery to run at night.

                          Wilf,

                          Just curious, how can a 3v batterry charge a cap to 300v? when the cap
                          reaches 3v how does it continue to accept voltage from a 3v source.
                          seems like anything over 3v would treat the 3v batterry as a ground. I
                          could be wrong, I'm still very new, and this may be a stupid question
                          but you never learn if you dont ask.

                          God Bless,
                          Chris

                        • chrisvaughan02
                          Thanks a lot wilf. I think I understand how it works. would it be prudent for me to build a test circuit and try to demonstrate this? or would it be
                          Message 12 of 12 , Jul 5, 2006
                            Thanks a lot wilf. I think I understand how it works. would it be
                            prudent for me to build a test circuit and try to demonstrate this?
                            or would it be dangerous to experiemnt with that much power, given my
                            novice status?

                            God Bless,
                            Christopher L. Vaughan

                            --- In beam@yahoogroups.com, "wilf" <wrigter@...> wrote:
                            >
                            > Good question Chris!
                            >
                            > The photoflash works similarly to an car ignition system which uses
                            a ignition coil (transformer) with a 12V primary winding and a high
                            voltage secondary winding to generate a 20,000V spark.
                            >
                            > The photoflash circuit generates 300V pulses and then uses a
                            rectifier to charge the high voltage cap from these high voltage
                            pulses.
                            >
                            > One type circuit that can convert a 3V source to a high voltage
                            pulse works as follows:
                            >
                            > 1. Turn on a transistor which switches to ground one side of an
                            inductor, connected on the other side to the 3V source.
                            >
                            > 2. This allows current to build up in the inductor winding, which
                            stores energy in an increasingly intense magnetic field.
                            >
                            > 3. When the current reaches a preset value, rapidly switch off the
                            transistor.
                            >
                            > 4. The collapsing magnetic field holds up the current by rapidly
                            driving the transistor collector voltage positive up to >300V. (This
                            requires the use of a high volatge transistor)
                            >
                            > 5. When the rising voltage on the transistor collector is slightly
                            higher than the voltage on the high voltage capcitor, the rectifier
                            turns on and the current from the inductor is discharged into the
                            capacitor.
                            >
                            > 6. Each high voltage pulse is rectified and increases the voltage
                            on the cap by a small step. For example, if the initial voltage on
                            the capacitor is 2.4V (the battery voltage minus a diode drop), then
                            the collector voltage rises only to about 4V for the first pulse,
                            then to 5V for the second pulse then to 6V for the next pulse and so
                            on.
                            >
                            > 7. A voltage sensor (neon bulb) turns on when the voltage reaches
                            300V and the current through the neon bulb is used to shut of the
                            high voltage capacitor charging circuit.
                            >
                            > 8. When the flash is fired, the high voltage cap is discharged
                            through a flash lamp filled with Xenon/Krypton/Argon gases which
                            produces an intense white light..
                            >
                            > 9. When the high voltage cap voltage drops below the neon bulb
                            turnoff voltage ( <200V), the HV charging circuit starts switching
                            again and the charge cyle repeats.
                            >
                            > More popular photo flash circuits use this circuit with a
                            transformer instead of an inductor. The low voltage winding uses a
                            few turns or wire on the magnetic core, The high voltage winding uses
                            many turns on the same core. That way the voltage pulse on the low
                            voltage side of the transformer is multiplied by the turns ratio
                            (typically 1:30). This allows the use of low voltage switching
                            transistor since the voltage on the collector on the low voltage
                            winding may rise to 10V while the high voltage winding voltage rises
                            to >300V to charge the cap.
                            >
                            > Hope that description helps answer your question.
                            >
                            > wilf
                            >
                            > ----- Original Message -----
                            > From: chrisvaughan02
                            > To: beam@yahoogroups.com
                            > Sent: Monday, July 03, 2006 7:18 PM
                            > Subject: [beam] Re: Using Photoflasher... "Rovore"...coming this
                            year! - THIS IS OFF TOPIC!
                            >
                            >
                            > --- In beam@yahoogroups.com, "wilf" <wrigter@> wrote:
                            > > The reason the neon light comes on so quick is that the 3V
                            battery
                            > supplies several amps of current. So you need to have some heavy
                            duty
                            > storage eg a 1F / 5V cap for one or two flashes or a rechargable
                            > battery to run at night.
                            >
                            > Wilf,
                            >
                            > Just curious, how can a 3v batterry charge a cap to 300v? when
                            the cap
                            > reaches 3v how does it continue to accept voltage from a 3v
                            source.
                            > seems like anything over 3v would treat the 3v batterry as a
                            ground. I
                            > could be wrong, I'm still very new, and this may be a stupid
                            question
                            > but you never learn if you dont ask.
                            >
                            > God Bless,
                            > Chris
                            >
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