The Ultimate Cap Dump

[Catrinisin]

Got the idea from magnetgate motor simple ssg backemf back to source

Has anyone considered using super capacitors instead of a run battery? Then back pop the source? (With or without a cap dump)

I've tried using a cap pulser with relay to dump into the source by disconnecting the source battery from the run side during the dump via a relay. This was just an experiment, but it did work technically. My run battery stayed at very close to the same voltage for a couple of hours. But after a couple of hours the battery was really warm. I noticed the next day that this battery no longer had great capacity. I had to cycle it a few times to get it to come back. So this tells me that rapidly charging and discharging a battery at the same time is a nogo. Capacitors on the other hand would not mind this at all. I was even thinking about trying some of those hybrid capacitors that have lithium ion chemicals. They charge fast like a cap, but discharge slowly like a battery.

Thoughts?

Thanks,
Chris

[Catrinisin]

Hi Chris,
I should preface this by saying John Bedini would be the best person to shed light on his comparator. Without him being here I can only speculate on what I have read him say and what I know from my experiments. In addition for anyone who has not read the opening of this thread. I started by saying that I’m on the HUNT for the ultimate cap dump and my hope was greater minds would lend their expertise here.

So far that’s you Chris! :-) You are on the cutting edge and have every right to post in this advanced thread.

I don’t think my comparator has any advantage over JB’s - never said that. Had he not used this SSR on his 13’ Ferris Wheel, I would never have headed down this path.

One thing to note is the power draw on mine is microwatts and good for small setups, however will still work with larger energizers. I hope this helps. Feel free to post more, would love to see your comparator in action…
-KR
Patrick

Thanks Patrick,

I've been wanting to make some videos but my lab desk here is such a horrific mess that I've been procrastinating. I'll clean up a bit here and shoot a video about my findings here.

Thanks,
Chris

[totoalas]

Hi Chris
Thanks for the tip
I would have done that cap pulser this weekend.....save my day for other tests
Without the battery mine will stop immediately.... there must be a storage somewhere to have the backemf back to source
Jack sholtz channel wayback in 2009 has a good schematic on the extra energy going back to source

There is a new hybrid cap/battery in China all in one unit maybe this will solve the problem budget constraints stalled mine at the moment and will be back again to test by June .....
happy experimenting

[Catrinisin]

Bedini 12V comparator circuit using SSR instead of mosfets

Hi Chris,
..... Feel free to post more, would love to see your comparator in action…
-KR
Patrick

Here you go guys, finally cleaned up my area a bit and shot a quick video of my Bedini comparator 12V SSR mod circuit. As you can see in the video, the scope shot indicates that as I increase the dump voltage, the voltage in the caps does in fact go up as it should. However, the voltage of the caps is not going all the way down to the battery voltage. The higher I make the voltage go, the higher the bottom end goes as you can see in the video. When I try this using an SCR and zener combo, I see the voltage of the caps go all the way down to the battery voltage. I know that with an SCR, it has to go all the way down before the SCR stops conducting and allows charging again. With this SSR or mosfet circuit, it seems to go a little too fast maybe?

Thanks,
Chris

[John_Koorn]

Hey Chris,

Good work. I'd say it's working perfectly You actually don't want the cap to dump down to the battery voltage. Because then you have to use up more energy to fill it up to the dump voltage again. The large current pulse that is sent to the charge battery when the cap dumps is sufficient to get the battery to charge.

The only thing I see different on your scope shot is that the SSR is actually not switching on as fast as the MOSFETs will. On my scope shots with the MOSFETs I see just about a vertical line when the caps dump. Having said that though, it could just be that the caps aren't fast discharging ones.

John K.

[Catrinisin]

Thanks John! This is the kind of feedback I need!

I'll hook up the mosfets again and get a scope shot of the dump and compare. But you could be right about the caps, they are surplus from an old CPU PS. I plan to spec out new parts for a final build when I decide on what to do.

Thanks again for the feedback, much appreciated.

-Chris

[min2oly]

Here you go guys, finally cleaned up my area a bit and shot a quick video of my Bedini comparator 12V SSR mod circuit. As you can see in the video, the scope shot indicates that as I increase the dump voltage, the voltage in the caps does in fact go up as it should. However, the voltage of the caps is not going all the way down to the battery voltage. The higher I make the voltage go, the higher the bottom end goes as you can see in the video. When I try this using an SCR and zener combo, I see the voltage of the caps go all the way down to the battery voltage. I know that with an SCR, it has to go all the way down before the SCR stops conducting and allows charging again. With this SSR or mosfet circuit, it seems to go a little too fast maybe?

Thanks,
Chris

Very nice Chris!
I knew someone could do it - what a nice setup, your use of the Joule-Ringer (?) ckt to charge batteries.
This is a simple and elegant - very clean stair step dump.
Thanks for sharing this.
Kind Regards,
Patrick

[min2oly]

I think you could be right about the caps - although SSR's are not all the same. the SSR's I have all dump w/ a clean line as well.

Chris,
try some different caps - or could your signal to the SSR be a little weak?
You'll appreciate this cap dump ckt when you get to your larger builds - even if your SCR/Zener work well now.
nice work!

Patrick

[Mostie]

Chris, there's no hysteresis on that circuit

[ZPDM]

Thanks ZPDM
my microwave 16 ring magnets from 8 microwave oven and 16 neodyne magnets from hd servers plus the wheel mags weighed in 40 kgs in my latest vids as for the rotation 1210 rpm I achieved with a DIY less sensor and less parts to deal with..... just sharing ..... TESLA PSYCHEDELIC MOTOR MISSION ACCOMPLISHED YT
AS FOR THE LEVEL STILL IN THE QUANDRY ?? TRYING TO FIGURE OUT WHY MY MOTOR WILL NOT STOP 24/7 FOR 3 WEEKS NOW WITHOUT EXTERNAL POWER ?????

cheers
totoalas

40 Kgs, Good Gravy!! I am graduating from Balsa to Bass wood. You know I feel a bit like someone who is presented blueprints for a violin. At first I say, I'm not sure that it might be a violin, then I say that might be a violin and start thinking well how does the rosin work on the bow, why are there holes in the violin and shaped that way, you know I bet you could make a trombone if you changed this that and the other. If I were an old world craftsman I might take the blue prints and make a Stradivarius, but for me, at the moment, I'd be lucky to make something for the elementary school orchestra, and as I said getting distracted I usually end up just making something like a mouth harp. Mind you I am making progressively better mouth harps. Give me some time, this is still all quite new to me, As Mike Myers, Dr. Evil said, "throw me a bone people, need the info."

Alright for something practical and on topic, for Min2oly, this is something I noticed that was for me consistent. As background I am finally starting to get the idea of impedance matching. So one thing I did a year or so ago was just take a coil pulse it with a function generator at its optimal rate and try charging different things, I noticed the amp draw for a battery was impeded less as it charged and that impedance changed with different capacitors at different levels of charge as well, and I thought I wonder if you could "cheat" and just gather energy at the low impedance levels? So impedance matching to me is this "cheating" the amp draw. The one thing I saw consistently with electrolytic caps was that the higher the voltage the cap the less amp draw for gathering a set amount of energy from the "spike". In addition, though it makes no sense to me, for say a 100 volt cap, the energy was gathered more efficiently from 50-100 volts than 0-50. So for a cap dump, my guess is you would have very good results with say an electrolytic cap dump oscillating between 200-400 volts.

As for the rest of your post Totoalas, that's crazy talk! Whachew cwazy???

[ZPDM]

Got the idea from magnetgate motor simple ssg backemf back to source

Totoalas,

I think I got something from your reference. I'm going to shut up and experiment for a while but thank you.

[Catrinisin]

Very nice Chris!
I knew someone could do it - what a nice setup, your use of the Joule-Ringer (?) ckt to charge batteries.
This is a simple and elegant - very clean stair step dump.
Thanks for sharing this.
Kind Regards,
Patrick

Thanks Patrick! You thanking me seems strange, lol with all you have done for us here, Thank You!
Yes that is the Joule Ringer circuit with the added diode. It does take away some of the light when I connect the cap dump to it.

I'm going to try wiring up a SS SSG using a spare coil I have sitting here and see how the dump likes that.

Chris

[Catrinisin]

I think you could be right about the caps - although SSR's are not all the same. the SSR's I have all dump w/ a clean line as well.

Chris,
try some different caps - or could your signal to the SSR be a little weak?
You'll appreciate this cap dump ckt when you get to your larger builds - even if your SCR/Zener work well now.
nice work!

Patrick

Okay I'll see if I can get some other caps to test with. What kind are best that discharge the fastest for this application?


Good to know that this will work for larger builds. I recently read about how the SCR doesn't like bigger setups. I'm replicating the Bedini SSG per the handbook currently so I'll need something that works with it. Got the frame cuts finished yesterday.

Chris

[min2oly]

Okay I'll see if I can get some other caps to test with. What kind are best that discharge the fastest for this application?

Chris

I wish I had a good answer for you
I think there must be a general rule of thumb. Can someone else chime in on this?
Thanks,
Patrick

[John_Koorn]

General rule of thumb is tall skinny ones, not short fat ones. Generally tall skinny ones have a lower ESR (Equivalent Series Resistance) and will charge and discharge faster that short fat ones.

Unfortunately they are usually more expensive The ones that JB used in the large comparator (15,000uF 80v) are about $12-$15 each.

John K.