"Enhanced Generator" from JPKBook

[mml]

Hello Jules,

answers below

Ok so the HV pulse from the generator's FET Drain (which reverses polarity and goes HV+) will connect directly to Pos of the Capture Cap. Where do the LM741 and the H11D1 get their power supply from?

The collapsing current of the coils, when the supply is cut off, is a positive current that must flow to a negative terminal (of a capacitor, or of a battery).

The 12V build then is suitable for a 36V setup and perhaps the lower threshold might be set at 40V and the upper at 48V but the lower in particular might need tinkering. Is it R10 that adjusts the lower and R13 the upper? I appreciate what hysteresis means in magnetic terms but not sure in this context (the amount of lag between the charge and discharge?) To clarify these thresholds visually is the attached right and the cap would normally discharge at the lower threshold?

It seems to me that the roles of R10 and R13 are those. The simplest method of tuning I found was to tune the high and low thresholds by feeding the Cap Pulser with a DC lab supply and placing a voltmeter at the output of the mosfets. Place a resistive load at the output to drop the voltage when cutting the source.
I specify that I have never tried to set the threshold higher than 48 V, but 23 / 24V.
The term "hysteresis" can also be applied to a device that has a control of the level of the ignition voltage different from that of stop. This is the case, for example, of the thermostat of a refrigerator. In Cape Pulser, there is a hysteresis comparator.

My small batteries are 7Ah each so three in series would happily be met with just one of those 15000uf caps?

A single capacitor 15000uf would suffice for 3 X 7 Ah.

cordially
mml

[JulesP]

Hi mml,

From your helpful information I have made my own attached drawing which is part of the build process for me. I hope it and the credits are right.

I would need to feed the discharges via my battery swapper to direct them to the battery stack that is not driving the whole circuit at that moment.

When I have finished testing the HV feed direct to the batteries I will start on this and let you know how it goes.

Regards,

Jules

PS. The 12V zener diode IN5242 seems hard to come by in modest numbers so can I replace that with a BZX55-C12V as I have quite a few of those? The other diodes I can get fine.

(In anticipation of what one earth will happen with Brexit )

[mml]

Hi Jules,

I read a little more my notes and some post of the thread "Bedini Comparator Cap Dump". I found this information concerning a modification to be made between the 2 Cap Pulser 12V and 36V.
For the 36V, D3 is a 15V zener diode;
For 12V, D3 is a 12V zener diode.

You can find the zener diode IN5242 at Farnell. I mainly buy my components at their home.
Link: https://uk.farnell.com/on-semiconduc...5?st=1N5242BTR

In your diagram, reverse the polarity of the white del (between terminal 6 of the LM741 and R1).

cordially
mml

[JulesP]

Thanks. If D3 needs to be a 15V Zener instead of 12V then perhaps I can just use the same as D2 (IN4744A)?

Regards

Jules

[JulesP]

Hi mml,

Having drawn up the circuit in readiness for the build I have come across an issue that seems to be relevant to the solid state design.

When looking at how to arrange the negative side connection ports on the circuit board I realised that if I connect the capture capacitor to the main negative rail of the generator then I am effectively bypassing the cap dump circuit which switches the negative line back to the batteries in order to release the stored charge. I have shown this in the attached pic and where the cap dump circuit is traditionally connected to an independent coil. In my case the HV pulses are being generated in relation to the battery negative/ground (FET Source) and so I can't connect the negative of the capture cap to that as it will discharge straight away.

I wondered if you can think of a simple solution to this?

Regards,

Jules

[mml]

Hi mml,

Having drawn up the circuit in readiness for the build I have come across an issue that seems to be relevant to the solid state design.

When looking at how to arrange the negative side connection ports on the circuit board I realised that if I connect the capture capacitor to the main negative rail of the generator then I am effectively bypassing the cap dump circuit which switches the negative line back to the batteries in order to release the stored charge. I have shown this in the attached pic and where the cap dump circuit is traditionally connected to an independent coil. In my case the HV pulses are being generated in relation to the battery negative/ground (FET Source) and so I can't connect the negative of the capture cap to that as it will discharge straight away.

I wondered if you can think of a simple solution to this?

Regards,

Jules

Hi Jules,

here is a solution that works, with a second battery.
In red: the circuit of the current when the coil collapses (Note: B1 does not discharge during this time, it just lets the current flow).
You can think of other solutions.

Cap Dump Circuit.jpg

cordially
mml

[JulesP]

Hi mml,

Based on your thinking I have one idea that might work that keeps my current battery setup with the swapper. As the problem is around the common ground line for the batteries and the capture capacitor, can't I just switch the positive line instead of the negative with the FETs in the circuit. I attach the basic idea.

Regards

Jules

[JulesP]

Like this . . . Looking back at SG Intermediate, where similar things are discussed, it appears that switching the positive will work just as well. The only downside is the 0.6V loss from the extra diode in the line but given that the capture cap will always be above the 36V battery voltage I might be able to dispense with it.

Jules