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Re: Need Help With A Voltage Multiplier Circuit

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  • Kerim F
    ... Hi John, You remind me the electronic door-lock opener I designed about 20 years ago. I had to open a 12V/3A lock by 4 small batteries after keying
    Message 1 of 10 , Mar 26, 2013
      --- In Electronics_101@yahoogroups.com, "johnny_a_58" <johnny_a_58@...> wrote:
      >
      > Hi, I'm not a complete newb, but yet no where near as competent as most folks here. I'm looking to build a circuit that takes 4 AA cells (6VDC) to 24 VDC. Seems easy enough to do with a voltage quadrupler or Cockcroft Walton Multiplier driven by a 555. My real problem is I need 3 Amps at the output, but only for a brief time. The quickest I would need to draw any current would be once every minute, I would need two pulses, one second apart.
      >
      > If I were to need 3 amps continuosly, I think I would need 3X4=12 amps from the battery (FAIL), but as I said I only need it intermittently. Does this sound feasable? It seems like flash units must do this.
      >
      > Also, if so, how do I prevent the 3 amp draw from exceeding the max current of and blowing the 555? An electrolytic between the 555 output and the "ladder" or maybe a driver stage?
      >
      > Thanks,
      >
      > John
      >

      Hi John,

      You remind me the electronic door-lock opener I designed about 20 years ago. I had to open a 12V/3A lock by 4 small batteries after keying properly the secret code.
      As Jankok5 has already pointed it out, at the first press on the keypad the MCU (AT89C2051) was supplied by the 4 batteries after which it started charging a 1000uF capacitor up to 20V (not 12V also monitored by the MCU) during the few seconds before ending the entry code. The high voltage was generated by a small coil (at each off transient) if I remember well. At that time, I had to produce the product manually, the internal controller and the external electronic keypad that were connected together via an audio coaxial cable. It was more complicated (relatively speaking) to assemble than my other products that had even better profits. Naturally, I had to stop making it soon after I sold a few units. For instance, the 4 batteries used to last not less than 2 years for opening the door of an office or house (usually during daylight) before they needed to be replaced.

      Kerim
    • AlienRelics
      MC34063 switching regulator wired for boost regulation. Use an output smoothing capacitor on the output that is sufficiently large to provide that 3A pulse.
      Message 2 of 10 , Mar 27, 2013
        MC34063 switching regulator wired for boost regulation. Use an output smoothing capacitor on the output that is sufficiently large to provide that 3A pulse.

        How long is the 3A pulse, and what is acceptable voltage sag during the pulse?

        Steve Greenfield AE7HD

        --- In Electronics_101@yahoogroups.com, "johnny_a_58" <johnny_a_58@...> wrote:
        >
        > Hi, I'm not a complete newb, but yet no where near as competent as most folks here. I'm looking to build a circuit that takes 4 AA cells (6VDC) to 24 VDC. Seems easy enough to do with a voltage quadrupler or Cockcroft Walton Multiplier driven by a 555. My real problem is I need 3 Amps at the output, but only for a brief time. The quickest I would need to draw any current would be once every minute, I would need two pulses, one second apart.
        >
        > If I were to need 3 amps continuosly, I think I would need 3X4=12 amps from the battery (FAIL), but as I said I only need it intermittently. Does this sound feasable? It seems like flash units must do this.
        >
        > Also, if so, how do I prevent the 3 amp draw from exceeding the max current of and blowing the 555? An electrolytic between the 555 output and the "ladder" or maybe a driver stage?
        >
        > Thanks,
        >
        > John
        >
      • johnny_a_58
        Thanks to everyone for the quick replies. Unfortunately, I don t have the answers to your questions yet. I m sort of winging it here. What I want to do is
        Message 3 of 10 , Mar 27, 2013
          Thanks to everyone for the quick replies. Unfortunately, I don't have the answers to your questions yet. I'm sort of winging it here. What I want to do is this:


          I want to build a timer for turning a water valve on and off. I have the long delay timer working, just a 555 in astable mode sending pulses to 2 decade counters for the long "off" time. That output triggers another 555 (second half of a 556) in monostable mode giving me the very short "on" time (as low as 1 second).

          Now if I pick a relay or an SSR and use that to control a 24V valve, basically I'm finished. However, I want to try and control an Orbit watering valve that I have (and is readilly available at a reasonable price). That valve needs a "momentary" (don't know how long) pulse on one lead to turn it on and a second one on another lead to turn it off (with a common ground).

          The newer Orbit valves work the same way except only 2 leads and the pulse needs to be reversed. If I did that I could just add an h-bridge at my output.

          I was thinking on the same lines about the big ecap at the end but wasn't sure one second later how quick it would recharge. I also looked at boost supplies like the LM2587S but I'm still trying to gather some support for my ideas as well as some fresh ones from the group.

          I really appreciate the help and will look into those ideas as well. I guess the answer to how long and the second being diminished will only be answered by my experimenting some.

          There is a circuit on a page called "Rays Hobbies" or close to that, he did a lot of experimenting work for me already but only states 24v at 3 A. Of course I could take the easy way out and just build a simple power supply from ac input, but again, then I'd be done ;-)

          Thanks, John


          --- In Electronics_101@yahoogroups.com, "AlienRelics" <alienrelics@...> wrote:
          >
          > MC34063 switching regulator wired for boost regulation. Use an output smoothing capacitor on the output that is sufficiently large to provide that 3A pulse.
          >
          > How long is the 3A pulse, and what is acceptable voltage sag during the pulse?
          >
          > Steve Greenfield AE7HD
          >
        • Jan Kok
          You could use two capacitors, one for the turn-on pulse and one for the turn-off pulse. Of course you d need some diodes to keep them separate so that
          Message 4 of 10 , Mar 27, 2013
            You could use two capacitors, one for the turn-on pulse and one for the
            turn-off pulse. Of course you'd need some diodes to keep them separate so
            that discharging one doesn't discharge the other.

            In the case of the bipolar valve, you could have one cap charged positive
            and the other charged negative (below "ground"). Then you could use just
            two MOSFETS (a half-H bridge) to switch the on and off pulses, not a full H
            bridge.

            Assuming the valves contain no semiconductors, it should be OK to use
            higher voltage than the rated 24V. For example, you could charge the caps
            to 30V and discharge down to 15V. That would allow using smaller
            capacitors, but might cause the valves to wear out faster.


            [Non-text portions of this message have been removed]
          • Derek
            The boost circuit with a single cap and an H-bridge would be my choice. There is a nice H-bridge that can handle 5A, Freescale 33886 I am looking at using for
            Message 5 of 10 , Mar 27, 2013
              The boost circuit with a single cap and an H-bridge would be my choice.
              There is a nice H-bridge that can handle 5A, Freescale 33886 I am
              looking at using for a motor drive project.

              There are small boost circuits out there that are current limited and
              you can then charge a large cap, or a super-cap bank.

              Do experiment with a charged cap to clearly identify what value you
              need. You can start by monitoring current and set 24V into the coil. See
              if the current drops at some time automatically. Or identify how long
              you really need the current draw to open or close the valve. Then the
              capacitor value can be determined. I would say an allowable of 5V drop
              on the capacitor is a good tight tolerance to start with. If the cap
              value is unreasonably large, then drop it down.

              Other option... use a boost circuit to keep a rechargeable battery bank
              charged to your 24V. This would eliminate any capacitor bleed loss
              between 0V to your minimum capacitor voltage. Thus you really need to
              change the battery that is running everything.The battery option may be
              better for space constraint.

              Derek Koonce
              DDK Interactive Consulting Services


              On 3/27/2013 12:28 PM, Jan Kok wrote:
              >
              > You could use two capacitors, one for the turn-on pulse and one for the
              > turn-off pulse. Of course you'd need some diodes to keep them separate so
              > that discharging one doesn't discharge the other.
              >
              > In the case of the bipolar valve, you could have one cap charged positive
              > and the other charged negative (below "ground"). Then you could use just
              > two MOSFETS (a half-H bridge) to switch the on and off pulses, not a
              > full H
              > bridge.
              >
              > Assuming the valves contain no semiconductors, it should be OK to use
              > higher voltage than the rated 24V. For example, you could charge the caps
              > to 30V and discharge down to 15V. That would allow using smaller
              > capacitors, but might cause the valves to wear out faster.
              >
              > [Non-text portions of this message have been removed]
              >
              >



              [Non-text portions of this message have been removed]
            • Howard Hansen
              You need to get more information on what Orbit means by momentary. Pneumadyne sells a line of latching solenoid valves with 10 milliseconds to energize and 12
              Message 6 of 10 , Mar 27, 2013
                You need to get more information on what Orbit means by momentary.
                Pneumadyne sells a line of latching solenoid valves with 10 milliseconds
                to energize and 12 milliseconds to de-energize operating times. See:
                <http://www.pneumadyne.com/normally-closed-latching-solenoid-valves-p-1448-l-en.html>
                If orbit makes valves with similar response times then all you need is a
                simple circuit to charge a capacitor and dump the charge into the
                solenoid coil.

                The other Howard



                On 3/27/2013 1:20 PM, johnny_a_58 wrote:
                >
                > Thanks to everyone for the quick replies. Unfortunately, I don't have
                > the answers to your questions yet. I'm sort of winging it here. What I
                > want to do is this:
                >
                > I want to build a timer for turning a water valve on and off. I have
                > the long delay timer working, just a 555 in astable mode sending
                > pulses to 2 decade counters for the long "off" time. That output
                > triggers another 555 (second half of a 556) in monostable mode giving
                > me the very short "on" time (as low as 1 second).
                >
                > Now if I pick a relay or an SSR and use that to control a 24V valve,
                > basically I'm finished. However, I want to try and control an Orbit
                > watering valve that I have (and is readilly available at a reasonable
                > price). That valve needs a "momentary" (don't know how long) pulse on
                > one lead to turn it on and a second one on another lead to turn it off
                > (with a common ground).
                >
                > The newer Orbit valves work the same way except only 2 leads and the
                > pulse needs to be reversed. If I did that I could just add an h-bridge
                > at my output.
                >
                > I was thinking on the same lines about the big ecap at the end but
                > wasn't sure one second later how quick it would recharge. I also
                > looked at boost supplies like the LM2587S but I'm still trying to
                > gather some support for my ideas as well as some fresh ones from the
                > group.
                >
                > I really appreciate the help and will look into those ideas as well. I
                > guess the answer to how long and the second being diminished will only
                > be answered by my experimenting some.
                >
                > There is a circuit on a page called "Rays Hobbies" or close to that,
                > he did a lot of experimenting work for me already but only states 24v
                > at 3 A. Of course I could take the easy way out and just build a
                > simple power supply from ac input, but again, then I'd be done ;-)
                >
                > Thanks, John
                >
                > --- In Electronics_101@yahoogroups.com
                > <mailto:Electronics_101%40yahoogroups.com>, "AlienRelics"
                > <alienrelics@...> wrote:
                > >
                > > MC34063 switching regulator wired for boost regulation. Use an
                > output smoothing capacitor on the output that is sufficiently large to
                > provide that 3A pulse.
                > >
                > > How long is the 3A pulse, and what is acceptable voltage sag during
                > the pulse?
                > >
                > > Steve Greenfield AE7HD
                > >
                >
                >



                [Non-text portions of this message have been removed]
              • Randy
                It s been 30+ years since I had any experience in nursery operations, whereby timing down the about the 1-second level was crucial for maintaining moisture
                Message 7 of 10 , Mar 27, 2013
                  It's been 30+ years since I had any experience in nursery operations,
                  whereby timing down the about the 1-second level was crucial for
                  maintaining moisture levels in cuttings....
                  and 20+ years since I had to work on irrigation systems in
                  residential/condo settings.
                  Unless you are reliant on solar power, or are doing this for the sake of
                  doing it, you can easily find a way
                  to provide power to old-school solenoid valves. If you don't trust the
                  irrigation-type valves, that rely on
                  water pressure worked against itself to turn itself on or off with the
                  aid of a tiny, electromagnetic plunger,
                  you might opt for the more positive shut-off type, such as might be
                  scrounged from a dishwasher or washing
                  machine, but which require 110VAC to operate. Note that
                  "spudzooka"/potato cannon operators often wire
                  3X 9V batteries in series to a common irrigation valve that "expects" 24
                  Volts, AC.
                  Furthermore, if your intention is to send water down various pathways,
                  there are what are known as "distribution
                  valves' that send water down 1-of-X output pipes, with a swappable
                  internal camshaft for 2, 3, 4, etc. outputs, with a change in output for
                  each time the water supply is cycled on/off.

                  Randy

                  On 3/27/2013 2:20 PM, johnny_a_58 wrote:
                  >
                  > Thanks to everyone for the quick replies. Unfortunately, I don't have
                  > the answers to your questions yet. I'm sort of winging it here. What I
                  > want to do is this:
                  >
                  > I want to build a timer for turning a water valve on and off. I have
                  > the long delay timer working, just a 555 in astable mode sending
                  > pulses to 2 decade counters for the long "off" time. That output
                  > triggers another 555 (second half of a 556) in monostable mode giving
                  > me the very short "on" time (as low as 1 second).
                  >
                  > Now if I pick a relay or an SSR and use that to control a 24V valve,
                  > basically I'm finished. However, I want to try and control an Orbit
                  > watering valve that I have (and is readilly available at a reasonable
                  > price). That valve needs a "momentary" (don't know how long) pulse on
                  > one lead to turn it on and a second one on another lead to turn it off
                  > (with a common ground).
                  >
                  > The newer Orbit valves work the same way except only 2 leads and the
                  > pulse needs to be reversed. If I did that I could just add an h-bridge
                  > at my output.
                  >
                  > I was thinking on the same lines about the big ecap at the end but
                  > wasn't sure one second later how quick it would recharge. I also
                  > looked at boost supplies like the LM2587S but I'm still trying to
                  > gather some support for my ideas as well as some fresh ones from the
                  > group.
                  >
                  > I really appreciate the help and will look into those ideas as well. I
                  > guess the answer to how long and the second being diminished will only
                  > be answered by my experimenting some.
                  >
                  > There is a circuit on a page called "Rays Hobbies" or close to that,
                  > he did a lot of experimenting work for me already but only states 24v
                  > at 3 A. Of course I could take the easy way out and just build a
                  > simple power supply from ac input, but again, then I'd be done ;-)
                  >
                  > Thanks, John
                  >
                  > --- In Electronics_101@yahoogroups.com
                  > <mailto:Electronics_101%40yahoogroups.com>, "AlienRelics"
                  > <alienrelics@...> wrote:
                  > >
                  > > MC34063 switching regulator wired for boost regulation. Use an
                  > output smoothing capacitor on the output that is sufficiently large to
                  > provide that 3A pulse.
                  > >
                  > > How long is the 3A pulse, and what is acceptable voltage sag during
                  > the pulse?
                  > >
                  > > Steve Greenfield AE7HD
                  > >
                  >
                  >


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                  [Non-text portions of this message have been removed]
                • Howard Hansen
                  The following link shows a circuit for controlling an Orbit latching solenoid valve and it uses a battery for a power supply.
                  Message 8 of 10 , Mar 28, 2013
                    The following link shows a circuit for controlling an Orbit latching
                    solenoid valve and it uses a battery for a power supply.
                    <http://www.cypress.com/?rID=49607>
                    You may not want to use a PSOC device. Instead notice the use of a
                    LT1303 charge pump to step up the battery voltage.

                    The other Howard




                    On 3/27/2013 11:04 PM, Howard Hansen wrote:
                    >
                    > You need to get more information on what Orbit means by momentary.
                    > Pneumadyne sells a line of latching solenoid valves with 10 milliseconds
                    > to energize and 12 milliseconds to de-energize operating times. See:
                    > <http://www.pneumadyne.com/normally-closed-latching-solenoid-valves-p-1448-l-en.html>
                    > If orbit makes valves with similar response times then all you need is a
                    > simple circuit to charge a capacitor and dump the charge into the
                    > solenoid coil.
                    >
                    > The other Howard
                    >
                    > On 3/27/2013 1:20 PM, johnny_a_58 wrote:
                    > >
                    > > Thanks to everyone for the quick replies. Unfortunately, I don't have
                    > > the answers to your questions yet. I'm sort of winging it here. What I
                    > > want to do is this:
                    > >
                    > > I want to build a timer for turning a water valve on and off. I have
                    > > the long delay timer working, just a 555 in astable mode sending
                    > > pulses to 2 decade counters for the long "off" time. That output
                    > > triggers another 555 (second half of a 556) in monostable mode giving
                    > > me the very short "on" time (as low as 1 second).
                    > >
                    > > Now if I pick a relay or an SSR and use that to control a 24V valve,
                    > > basically I'm finished. However, I want to try and control an Orbit
                    > > watering valve that I have (and is readilly available at a reasonable
                    > > price). That valve needs a "momentary" (don't know how long) pulse on
                    > > one lead to turn it on and a second one on another lead to turn it off
                    > > (with a common ground).
                    > >
                    > > The newer Orbit valves work the same way except only 2 leads and the
                    > > pulse needs to be reversed. If I did that I could just add an h-bridge
                    > > at my output.
                    > >
                    > > I was thinking on the same lines about the big ecap at the end but
                    > > wasn't sure one second later how quick it would recharge. I also
                    > > looked at boost supplies like the LM2587S but I'm still trying to
                    > > gather some support for my ideas as well as some fresh ones from the
                    > > group.
                    > >
                    > > I really appreciate the help and will look into those ideas as well. I
                    > > guess the answer to how long and the second being diminished will only
                    > > be answered by my experimenting some.
                    > >
                    > > There is a circuit on a page called "Rays Hobbies" or close to that,
                    > > he did a lot of experimenting work for me already but only states 24v
                    > > at 3 A. Of course I could take the easy way out and just build a
                    > > simple power supply from ac input, but again, then I'd be done ;-)
                    > >
                    > > Thanks, John
                    > >
                    > > --- In Electronics_101@yahoogroups.com
                    > <mailto:Electronics_101%40yahoogroups.com>
                    > > <mailto:Electronics_101%40yahoogroups.com>, "AlienRelics"
                    > > <alienrelics@...> wrote:
                    > > >
                    > > > MC34063 switching regulator wired for boost regulation. Use an
                    > > output smoothing capacitor on the output that is sufficiently large to
                    > > provide that 3A pulse.
                    > > >
                    > > > How long is the 3A pulse, and what is acceptable voltage sag during
                    > > the pulse?
                    > > >
                    > > > Steve Greenfield AE7HD
                    > > >
                    > >
                    > >
                    >
                    > [Non-text portions of this message have been removed]
                    >
                    >



                    [Non-text portions of this message have been removed]
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