The Ultimate Cap Dump

[RS_]

Hi Alvaro,

a 2n2222 would be the minimum size transistor... A BD243C would be better......

yes, a diode from the pos rail to R1 should help....

[AlvaroHN]

RS can I add a resistor between positive rail and opto+transistor so the zener don't drain too much C1 ??? in your SNAG02 schematic the 15V zener goes straight to positive rail through bd243 with no resistance in the middle. Why is that? on my comparator SNAG02 circuit, my bd243 gets hot if the dump is fast, maybe because the zener dissipating too much?

[RS_]

It does not need a resistor, as their is a voltage drop across the BD243C, and the Zener will only conduct if the voltage while the BD243C is on, is above it's threshold. If the Mosfet is triggered fast enough, and the cap dump is fast enough to drop below the threshold, than it will never conduct... If you are running a 24V+ pulser, than it needs other adjustments.....

if the BD is getting hot, mount it on a big heat sink..... or use a opto to 2n2222 to trigger the BD243C in a Darlington amp config, to help the mosfet to turn on harder / faster......

[AlvaroHN]

Tnx RS_, I will add a diode before R1 and see what happens, I might add a transistor between opto and mosfet but I think there is no space in that small board that I used for that. I was looking at h11d1 datasheet it says 100 ma current... and this small cap dump is using only 1 mosfet with 220 on the base, so I = 15v/220 = 68mA. Now I understand why you use a bd243... with 2 or more mosfets the opto's 100 mA current wouldn't be enough. I = 15v/110 = 136mA < 100 mA.

About the zener, can I put it like this??? between negative and base (after 220 ohms) or it does have to be on emiter of transistor/opto

[RS_]

put it across R5, and that will work too..... gate to source......

[AlvaroHN]

put it across R5, and that will work too.....

LOL! I connected it after the mosfet in the previous post...

here is the corrected drawing, bd243c included etc.

[RS_]

that should work much better

the Q3 transistor symbol is up side down..........

[AlvaroHN]

Corrected

[Nanuhi]

This will run and run and run and run.....
[ATTACH=CONFIG]3009[/ATTACH]

Patrick, it is so much time gone since your post (#238), but could you tell is the base of transistor unconnected? Or you pulse it by another gen or some other way?

Thanks.
Alexey.

[min2oly]

Patrick, it is so much time gone since your post (#238), but could you tell is the base of transistor unconnected? Or you pulse it by another gen or some other way?

Thanks.
Alexey.

I Alexey,
That is the "negistor" switched transistor, so no nothing connected to the base. The cap builds up because of the resistor when the potential is high enough for the transistor, it automatically triggers and the juice flows through the circuit then auto shut off and it repeats. Use an npn transistor and just put it together, use a potentiaometer and use one LED to start you'll see :-)
Cheers - Patrick

[Nanuhi]

Patrick, thank you for explanation.

Firstly, I think it is offtopic here... sorry... Is it possible to move your Negistor project to new thread for further negotiation?

I tried to replicate your device, though not with success at the moment. There is generation presents within the system but no light. I used coil with twice as thing copper wire though but with more length, so it is close to 23 Ohms.

[min2oly]

Patrick, thank you for explanation.

Firstly, I think it is offtopic here... sorry... Is it possible to move your Negistor project to new thread for further negotiation?

I tried to replicate your device, though not with success at the moment. There is generation presents within the system but no light. I used coil with twice as thing copper wire though but with more length, so it is close to 23 Ohms.
[ATTACH=CONFIG]6019[/ATTACH]

Hi Alexey,
I started the thread, I'll let you know if it's off topic Do you know what the thread is about? This Negistor is the basis of how the Ultimate Cap Dump derives it's energy to trigger the FET.

You must adjust/balance either and/or
voltage/cap/resistance

"I used coil with twice as thing copper wire though but with more length"
I'm really sorry I don't know what this means. you should not have too much of a problem using 23ohm coil depending on Awg/thickness of your coil. If it's too thin, it's probably using up the energy. Looking at your scope, I would play around with different coils before trying to adjust the other parts. It does not have to be 20 ohms - I'm assuming you are using exact other parts...




KR - Patrick

[Nanuhi]

Finally, it is working. Thanks for the idea. But the coil I use is not for this circuit. Too long and thin wire. As a result - very low frequency and low power.

Nevertheless, the whole idea of using a transistor in such a way is totally new for me. And I'm very grateful to you for this. It opens a lot of practical usage far beyond this small device.

Thank you one more time!

Alexey.

[vallentin]

Hi guys.
I finished my comparators (Ron and Rs versions) and both run like a charm.
Many thanks to all of you for the schematics, mods and corrections ☺.
I run the comparators on a solid state SSG (7 strands), my capacitor (for now) is 18.000uF/63V (big can), dump frequency is 16Hz at 29V. The Mos-Fet's are cold.
While running, I hear a noticeable click on my battery bank and the cells boil. Cold boil.
I am unable to measure the current going into the battery. My analog ammeter is either bad or unable to see it at 16Hz.
My question is how do you guys size your capacitor bank to your source (SSG in my case) and battery bank.
I want to do it right.
My bank is 2x12V/250A with 5OPzS250 cells (made by TAB).
Thanks!
Valentin

[Catrinisin]

Hey Vallentin,

I'm not sure there is a truly correct answer. That said, my comparator dumps at 2 Hz from an 8 filer SG wheel machine. The caps are sized at 40000uF/25V. I charge all the way to 25volts on the caps and it dumps down to about 18 volts before starting to charge again.

Any video I've ever seen of Bedini himself running this circuit, his dumps were around 1 to 2 Hz. I think maybe I saw 4Hz or so when his machine was run in generator mode/common ground mode, as demonstrated by Peter Lindemann and Aaron Murakami.

Anyways, hope this helps
Chris