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Voltage Triggered Capacitor Pulser with Schmitt Trigger

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  • Voltage Triggered Capacitor Pulser with Schmitt Trigger

    Hello all
    This is a new circuit of a Voltage Triggered Capacitor Pulser with Schmitt Trigger that I have compiled. The idea is to use a schmitt Trigger, to let the cap charge to 24V then down to 17V or so, then back to 24V. This is a theoretical design at this stage.

    Cap Pulser with Schmitt Trigger.pdf

    Q1,R1,R2 and ZD1 offer no voltage regulation in any way. The purpose of this circuit is to let the cap (C1) charge up to 15V with nothing loading it. When the cap(C1), charges to 15V, Q1 gets turned on, and lets power flow to IC1, then C3 stores some power. VR1 provides an adjustable voltage to appear at pin2 of IC1. C2 is connected across VR1 so that any voltage spikes are actively filtered out by IC1. (very similar to the beta multiplier gyrator filter in Bedini's "Linear Amp Regulator")

    R4,ZD2 and C4 provide a static voltage reference for the schmitt trigger and the comparator. VR2 sets the threshold voltage which the "schmitt trigger" triggers/turns on. When the "schmitt trigger" turns on this switch's the comparator on very fast. When the "Schmitt trigger" turns off, the comparator turns off very fast.

    The comparator drives the mosfets "Q2,Q3,Q4 and Q5" on and off at a very sharp slew rate. VR1 should be adjusted so that the mosfets are driven hard at 15V or so.

    The Schmitt Trigger has been shown as a block, because the internal circuit of this block needs further experimenting with.

    Schmitt trigger
    Last edited by Nityesh Schnaderbeck; 11-18-2014, 09:27 PM.

  • #2
    developed by studying squid nerves...... go figure!!

    Tom C

    experimental Kits, chargers and solar trackers


    • #3
      The development of the Schmitt trigger was by studying the nerves in squid, wow. I did not know that.

      Using just a comparator alone, does not empty the cap, it only maintains the cap at the set voltage. The "schmitt trigger" was the only solution to this problem that I could think of. So the "schmitt trigger" in my case has a static voltage reference.

      For example if the reference voltage is 21V, the schmitt trigger will turn on at 24V, 3V above the 21V reference, and turn off at 18V, 3V below the refrence voltage. So the turn off and turn on is symmetrical to the reference voltage, so turn on at 3V above the reference voltage, and turn off at 3V below the reference voltage. Of course it all depends on how you design it.

      Since the "schmitt trigger" is being used at a low frequency, it can have unwanted oscillations. That is why some experimentation is needed, to develop this stage, to make sure it does not oscillate. Otherwise the "Voltage Triggered Capacitor Pulser with Schmitt Trigger" circuit is pretty straight forward.

      Just another note, this design also needs to have a clamping circuit on the cap to make sure it does not charge over 30V. In case the battery gets disconnected while the SSG is running.

      If the capacitor (C1) does not discharge below 17V or so, then the wheel runs faster, than if it was discharged to 12V.

      The ideal situation is to have two simultaneous cap dumps at the same time, one cap dump to the battery, the other cap dump, to dump into another capacitor, to power the control circuits. So nothing at all is loading the capacitor while it is charging.

      The control circuit only needs power, to turn on and off the mosfets at the capacitor dump threshold voltages.

      So if you spend lots of money to get very good capacitor, that has no leakage, and because it has no leakage(infinite resistance) , it charges up very good with high voltage radiant spikes. Then you connect resistances across it, from a control circuit. Now you have made a leaky capacitor, now the high voltage spikes are loaded, by parallel resistances across the capture capacitor. John Bedini had always said that if you connect voltage meters across the battery, while it was charging the COP would be less. I am talking about a SSG charging the battery straight from the diodes, without a capacitors pulsar or a "linear amp regulator". And voltage meter/multimeter is in order of megaohms.

      So the voltage sensing of the capture capacitor has to have a very high resistance, there would be a trade off. High impedance voltage sensing is worth investigating.
      Last edited by Nityesh Schnaderbeck; 11-21-2014, 08:11 AM.


      • #4
        Op-Amp Schmitt Trigger

        Here are 2 op-amp schmitt trigger circuits, an inverting circuit and a non-inverting circuit.


        Both circuits have adjustable Hysteresis and adjustable reference voltages. The hysteresis is always symmetrical to the reference voltage.

        Adjusting the hysteresis, will vary the threshold that the capture capacitor charges to, and the threshold which the capture capacitor discharges to, when used in the Voltage Triggered Capacitor Pulser with Schmitt Trigger circuit. Adjusting the reference voltage can move the charge offset above the charging battery voltage. So the capture capacitor can discharge to 12V or above like 15V or 23V. According to how this is adjusted.

        Here is the Voltage Triggered Capacitor Pulser with Schmitt Trigger circuit with a non inverting adjustable schmitt trigger.

        Cap Pulser with Schmitt Trigger1.pdf

        VR1(10K) can be replaced with a fixed resistor, when the correct bias voltage is found to drive the mosfets. C5 stops the schmitt trigger from going into unwanted oscillations. VR2(100k) adjusts the reference voltage and VR3(100k) adjusts the hysteresis.

        If you build this circuit, or have any ideas please give me some feedback. I would love to hear from you, enjoy
        Last edited by Nityesh Schnaderbeck; 11-21-2014, 08:30 AM.


        • #5
          What is Q1, Schchmitt triger and compatitor part numbers! thanks.


          • #6
            Originally posted by ryan2000 View Post
            What is Q1, Schchmitt triger and compatitor part numbers! thanks.
            Q1 = PN2907

            Schchmitt trigger and comparitor = LM358

            Nityesh Schnaderbeck