CPD mod - capacitor potentiometer diode modification

[intactsaphir]

Bonjour min2oly.

Dans ce nouveau circuit que vous nous proposez, Je souhaiterais savoir si la batterie primaire se decharge plus ou moins rapidement qu'avec le montage originel.

Merci de me repondre.
Cordialement.

Hello min2oly.

* In this new circuit you are proposing, I would like to know if the primary battery discharges faster or slower than the original installation.

Thank you to answer me.
bests regards.

[min2oly]

Bonjour,
what is intactsaphir?

Thank you,
Patrick A.

Bonjour min2oly.

Dans ce nouveau circuit que vous nous proposez, Je souhaiterais savoir si la batterie primaire se decharge plus ou moins rapidement qu'avec le montage originel.

Merci de me repondre.
Cordialement.

Hello min2oly.

* In this new circuit you are proposing, I would like to know if the primary battery discharges faster or slower than the original installation.

Thank you to answer me.
bests regards.

[intactsaphir]

Bonjour,
what is intactsaphir?

Thank you,
Patrick A.

hello
What is intactsaphir?
It is my French pseudonym?

What is min2oly?

bests regards.

[min2oly]

Hi Aln,
I'll reply to your inquiry here. I kind of like reading this info all in one thread rather than hunting down snippets...

Not having the resistor there may very well have been the answer...

So I'm assuming you mean the transistor is heating up. Transistors heat up for one reason... too much current through the transistor.

there are many ways to bring that down. find the post where I talk about what the resistor does vs the pot vs the diode in relation to ON time vs duty cycle vs number of pulses.

Once you can control these 3 things, you will control the current going through the transistor.

Also......... what is the resistance on your 14 Awg wire? How many feet you got there :-)
KR - Patrick A.

To answer joe's question from last year before I hijack his thread, too much! I am currently working on a couple projects I had hoped to share by now but this question is related to an issue I am having. When using the SS SSG w/ CPD mod, I am finding that if I put a resistor after the Cap/pot and before the diode it will get HOT. My solution was to just not have the resistor there, but maybe I did something wrong, any insight would be helpful. Aln [#14 power #20 trigger, MJL21194 transistor, air core, 10k pot.]

[Brodie Gwilliam]

in my cpd ssg i also get heat in my resistor thats parallel with the capacitor.... its rheostat and a 100 ohm 20w resistor so it never falls below 100 ohms... i never really get much heat on my trannies but that 100 ohm resistor gets pretty damn hot.... it sure charges amazing but always wondered why there was so much heat there

[min2oly]

in my cpd ssg i also get heat in my resistor thats parallel with the capacitor.... its rheostat and a 100 ohm 20w resistor so it never falls below 100 ohms... i never really get much heat on my trannies but that 100 ohm resistor gets pretty damn hot.... it sure charges amazing but always wondered why there was so much heat there

Hi Brodie,
any heat produced is heat wasted, my first analysis would be to look at the size cap you are using vs resistance across that cap. The cap is what should drive your frequency. you can change the freq by sizing the cap. You might be driving it too hard?

Large cap takes longer to fill therefore your freq will be slower. You want to size the cap based on your coil and the battery you are charging.

once you do that then you bring in the resistance across the cap. Watch this method for that:

Here are a few ramblings I hoped might help anyone trying to get free triggering and better charging from their solid state devices. It should be very simple:

Kind Regards,
Patrick

Some people have left out the Pot/resistor across the cap and the diode altogether and have had fantastic results just using the cap. Being able to do this will depend on your transistors and coil...
Hope that helps,
Patrick A.

[Brodie Gwilliam]

ive got a 8 primary 18awg and a 20awg trigger...130'.... its air core and im using one of those yellow 250v capacitors of ricks.... i thought you were running one of yours off this same cap?? the frequency is quite low about 850hz when running it at full power (4amps) and about 1500hz at the point of switchover to squarewave.... about 2.2 amps

[aln]

Hi Aln,
I'll reply to your inquiry here. I kind of like reading this info all in one thread rather than hunting down snippets...

Not having the resistor there may very well have been the answer...

So I'm assuming you mean the transistor is heating up. Transistors heat up for one reason... too much current through the transistor.

there are many ways to bring that down. find the post where I talk about what the resistor does vs the pot vs the diode in relation to ON time vs duty cycle vs number of pulses.

Once you can control these 3 things, you will control the current going through the transistor.

Also......... what is the resistance on your 14 Awg wire? How many feet you got there :-)
KR - Patrick A.

I have 2 different coils that I am playing with, both have heat on the resistor I tried to describe (in series with the cap that is across the pot and then this hot resistor then to the diode then to the base of the transistor that also gets hot with that resistor in).

One coil is 4 filar, one #20 and three #14. this coil I have the the #20 and one of the #14's in series for the trigger and the other 2 pwr winds in series. Each was about 45', now 90' as they have been placed in series.

The other coil very unconventional: its about 65' of #14 and 130' of #20 (and an extra strand of 75' of #28 to play around with as a generator). So possibly I have too little of resistance/inductance on the #14 wire with my current set up. Thanks for bringing me to this thread, knew it existed but forgot where it was. Al

[aln]

Patrick,
Just looked at your schematic again and I did not put the 100 ohm resistor after the diode before the base will that help? I'll try it. Al

[min2oly]

ive got a 8 primary 18awg and a 20awg trigger...130'.... its air core and im using one of those yellow 250v capacitors of ricks.... i thought you were running one of yours off this same cap?? the frequency is quite low about 850hz when running it at full power (4amps) and about 1500hz at the point of switchover to squarewave.... about 2.2 amps

Fantastic! That's a good cap for that coil. Now, did you try the experiment I show in the video w/o the diode or resistor?
Patrick

[min2oly]

Patrick,
Just looked at your schematic again and I did not put the 100 ohm resistor after the diode before the base will that help? I'll try it. Al

yes/no that may or may not help. I think I've wrote about this before... there are 4 components here to balance

CAP
POT
Diode
RESISTOR

each of these actually control 4 separate things.

CAP - controls the freq
POT - more subtle and difficult to understand - controls your ability to control the freq of the CAP.
DIODE - allows you to have multiple spikes per "cap dump"(this refers to the above cap)
DIODE - also allows the energy to go ONLY in one direction.

RESISTOR - controls the ON time of the frequency - if you think about it, it's pretty common sense, by having a little resistance here it will take longer for the cap to discharge to the base and the transistor will be ON longer

I'll ask the same question, have you been able to run the experiment I show in the vid w/o Pot or Diode?
Thanks,
Patrick

[Brodie Gwilliam]

i dont have time to fiddle at the time being, but i was wondering if you could discuss what you did on your coil to reduce heat in resistor... i thought you had a similar coil and could just say the changes that need to be made.... i have 100 ohm resistor right before the bases on my coil and they stay cool, its just the 100 ohm and or rheostat parallell'd to the yellow 10uf capacitor that heat up.... ive made a couple of these back in the day with different coils and smaller capacitors and such, but whenever i push em into the square wave and beyond i find heat starts to come out in that resistor....

[min2oly]

i dont have time to fiddle at the time being, but i was wondering if you could discuss what you did on your coil to reduce heat in resistor... i thought you had a similar coil and could just say the changes that need to be made.... i have 100 ohm resistor right before the bases on my coil and they stay cool, its just the 100 ohm and or rheostat parallell'd to the yellow 10uf capacitor that heat up.... ive made a couple of these back in the day with different coils and smaller capacitors and such, but whenever i push em into the square wave and beyond i find heat starts to come out in that resistor....

So anyone running into this same situation, just spend a few minutes watching the video then do it on your own coil and you will have your answer. If I come right out and say it, the numbers will be wrong for your particular coil anyway so I would not be helping. It really is very simple.

Let me know if you run into any problems, you do not have to desolder anything just use jumpers... it should only take a few minutes, quicker than this exchange for sure.

fyi - I pretty much spell it out in the vid. you do not have to figure out why the heat is there, just follow my example and it will not be there.

KR - Patrick

[aln]

Will do the experiment, watched the video when you posted and again last night. Thanks for taking the time to respond, I will take the time to do the work. Have no time for next 2 weeks except tonight so if I get to it tonight I will update otherwise it will be a bit. P.S. I changed my transistor last night because I had burnt it out and got out a mega ohm pot as well. Also accidently broke the arm of my yellow cap from r_charge (same as yours) and solder was not keeping it on, but I had a couple more sitting around so I'm still good on those. Al

[Brodie Gwilliam]

so i tried some 1uf film capacitors and was still getting some heat... i got both the 1uf and the 10uf to resonate by bypassing the diode... 10uf ran at 2.2 amps(exact same amp draw as when the capicitor/resistor combo turns to square wave), and the 1uf about 1 amp... 1uf faster frequency as you would expect.... i feel like the 1uf was maybe a little less heat in the paralleled resistor when pushed to 4 amps, but was also in my opinion, not as nice of a squarewave.... the on time seemed longer.... any theories pat?