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RE: [beam] Re: 555 timer

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  • Wilf Rigter
    Pure BEAM and one of the simplest 555 circuits that does something useful! Sub a 2N2222 for higher current. Attached is an even simpler phototropic version
    Message 1 of 13 , Mar 28, 2002
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      Pure BEAM and one of the simplest 555 circuits that does something useful!
      Sub a 2N2222 for higher current. Attached is an even simpler phototropic
      version configured as a two motor photopopper. Is a CMOS 5556 available?

      wilf


      -----Original Message-----
      From: Manfred Schaffran
      To: beam@yahoogroups.com
      Sent: 3/28/02 4:48 AM
      Subject: Re: [beam] Re: 555 timer

      Hi Myc and Steve,

      i think that i am one of the "old timers" and i love this 555 timer,
      too.
      i made a simple solar engine with the cmos version. the trigger voltage
      is
      about 2.6 V.
      the current during loading is about 60µA or less.

      have fun

      manfred

      BTW: Wilf, your flasher is hard to beat :-) ! great.




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      <<555se2.gif>>
    • Pat Nicklas
      ... Sure is. TI s got em. Here s a list of all their timers: Check out the TLC556. Later, Pat
      Message 2 of 13 , Mar 28, 2002
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        >From: Wilf Rigter <wilf.rigter@...>
        >Date: Thu, 28 Mar 2002 06:59:18 -0800
        >

        >... Is a CMOS 5556 available?
        >

        Sure is. TI's got em. Here's a list of all their timers:
        <http://www-s.ti.com/cgi-bin/sc/family3.cgi?family=TIMERS>
        Check out the TLC556.

        Later,

        Pat


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      • Wilf Rigter
        My first reply on this subject got lost so here it is again slightly improved but still untested. Idea inspiring circuit Manfred! Pure BEAM and one of the
        Message 3 of 13 , Mar 28, 2002
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          My first reply on this subject got lost so here it is again slightly
          improved but still untested.

          Idea inspiring circuit Manfred!

          Pure BEAM and one of the simplest 555 circuits that does something useful!
          Sub a 2N2222 for higher current. Attached is an even simpler phototropic
          version configured here as a two motor photopopper using a CMOS 556. The
          photovoltaic voltage of one PD is around .5V, so with two PDs we generate
          1V. Given the internal "divide by three" bias network, the trigger should be
          3V and the reset 2V in bright light. In the dark it will be about 2.4V and
          1.6V, nicely tracking the lower solar cell output.

          wilf


          -----Original Message-----
          From: Manfred Schaffran
          To: beam@yahoogroups.com
          Sent: 3/28/02 4:48 AM
          Subject: Re: [beam] Re: 555 timer

          Hi Myc and Steve,

          i think that i am one of the "old timers" and i love this 555 timer,
          too. i made a simple solar engine with the cmos version. the trigger voltage
          is about 2.6 V. the current during loading is about 60µA or less.

          have fun

          manfred
        • Wilf Rigter
          And then again, an even bolder simpler solution. The 555 normally has an active high output which can source 10ma when high. But the 555 output can sink 100ma
          Message 4 of 13 , Mar 28, 2002
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            And then again, an even bolder simpler solution. The 555 normally has an
            active high output which can source 10ma when high. But the 555 output can
            sink 100ma when inactive low! Since the 555 input structure is symmetrical
            it should be possible to use it in the inverted mode with the output
            normally high and active low. For this application the OUT and DISCHARGE
            pins can be paralleled which in theory provides up to 200mA sink capability.
            The actual sink current varies with temperature and supply voltage but
            should be at least 50mA at 3V with a reasonable forward voltage drop. This
            inverted mode SE design applies equally to a CMOS 555 and the attached CMOS
            556 application.

            wilf

            -----Original Message-----
            From: Wilf Rigter [mailto:wilf.rigter@...]
            Sent: Thursday, March 28, 2002 8:16 AM
            To: 'beam@yahoogroups.com'
            Subject: RE: [beam] Re: 555 timer


            My first reply on this subject got lost so here it is again slightly
            improved but still untested.

            Idea inspiring circuit Manfred!

            Pure BEAM and one of the simplest 555 circuits that does something useful!
            Sub a 2N2222 for higher current. Attached is an even simpler phototropic
            version configured here as a two motor photopopper using a CMOS 556. The
            photovoltaic voltage of one PD is around .5V, so with two PDs we generate
            1V. Given the internal "divide by three" bias network, the trigger should be
            3V and the reset 2V in bright light. In the dark it will be about 2.4V and
            1.6V, nicely tracking the lower solar cell output.

            wilf


            -----Original Message-----
            From: Manfred Schaffran
            To: beam@yahoogroups.com
            Sent: 3/28/02 4:48 AM
            Subject: Re: [beam] Re: 555 timer

            Hi Myc and Steve,

            i think that i am one of the "old timers" and i love this 555 timer,
            too. i made a simple solar engine with the cmos version. the trigger voltage
            is about 2.6 V. the current during loading is about 60µA or less.

            have fun

            manfred
          • Manfred Schaffran
            thanks wilf, i m a little in hurry - just want to show you a 555 bicore. explanation later... have fun manfred
            Message 5 of 13 , Mar 28, 2002
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              thanks wilf,

              i'm a little in hurry - just want to show you a 555 bicore.

              explanation later...

              have fun

              manfred
            • Wilf Rigter
              Here is a slightly revised version that looks and feels more like a grounded bicore. Your original design was a master slave design with the two outputs
              Message 6 of 13 , Mar 28, 2002
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                Here is a slightly revised version that looks and feels more like a grounded
                bicore.
                Your original design was a master slave design with the two outputs driving
                one motor.
                So the motor would turn forward, stop, reverse, stop like a microcore.

                wilf


                -----Original Message-----
                From: Manfred Schaffran [mailto:Manfred.Schaffran@...]
                Sent: Thursday, March 28, 2002 11:06 AM
                To: beam@yahoogroups.com
                Subject: [beam] Re: 555 timer


                thanks wilf,

                i'm a little in hurry - just want to show you a 555 bicore.

                explanation later...

                have fun

                manfred


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              • Manfred Schaffran
                Hi Wilf, i little time ago, i found my old 555 SE design. It has never worked as good as i expected. After a little debug session i found out, that the
                Message 7 of 13 , Mar 28, 2002
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                  Hi Wilf,

                  i little time ago, i found my old 555 SE design. It has never worked as good
                  as i expected. After a little debug session i found out, that the internal
                  transistor was the main problem. So i give this circuit a extra BC547B
                  (=2N3904) and voila! this little SE was very good.

                  When i saw your schematic with output and discharge in parallel i was deeply
                  impressed. that is exacly what i was looking for. a wonderful idea !

                  i forgot the internal voltage diver in my design. this could replace the
                  resistor. i' m not shure if it will work with the cmos version of the 555,
                  cause the resistors are replaced with 6 mosfets.(according to the TI
                  datasheet). i will build the se in the next days.
                  anyway, it is always an inspiration to see your designs.

                  manfred
                • Wilf Rigter
                  Thanks Manfred, I greatly appreciate your comments. The trick of connecting the OUT and Discharge pins together just popped out of the internal schematic of
                  Message 8 of 13 , Mar 28, 2002
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                    Thanks Manfred,

                    I greatly appreciate your comments. The trick of connecting the OUT and
                    Discharge pins together just popped out of the internal schematic of the TI
                    TLC555 probably because of your unconventional BEAM application of this
                    chip. I was never used a 555 before, even though it was probably the most
                    popular IC ever made. Now that I finally discovered a BEAM use for the CMOS
                    version it looks promising for other designs too.

                    wilf

                    -----Original Message-----
                    From: Manfred Schaffran
                    To: beam@yahoogroups.com
                    Sent: 3/28/02 4:38 PM
                    Subject: Re: [beam] 555 timer

                    Hi Wilf,

                    i little time ago, i found my old 555 SE design. It has never worked as
                    good
                    as i expected. After a little debug session i found out, that the
                    internal
                    transistor was the main problem. So i give this circuit a extra BC547B
                    (=2N3904) and voila! this little SE was very good.

                    When i saw your schematic with output and discharge in parallel i was
                    deeply
                    impressed. that is exacly what i was looking for. a wonderful idea !

                    i forgot the internal voltage diver in my design. this could replace the
                    resistor. i' m not shure if it will work with the cmos version of the
                    555,
                    cause the resistors are replaced with 6 mosfets.(according to the TI
                    datasheet). i will build the se in the next days.
                    anyway, it is always an inspiration to see your designs.

                    manfred



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