Bedini Comparator Cap Dump

[Tom C]

Hy guys long time no see....Tom if you compare 1 cap to 3 caps yes you cannot see the diference,but if you add 10caps as i did they would take much longer to charge 3sec instead of 1...

I am sure there is a point but I was pretty shocked that when we went from 60,000 to double that, nothing changed... all I was trying to communicate is that you want as much cap uF size to get the entire spike, and adding caps till discharging slows down is a good way to figure that value.

Tom C

[adys15]

Hy guys long time no see....Tom if you compare 1 cap to 3 caps yes you cannot see the diference,but if you add 10caps as i did they would take much longer to charge 3sec instead of 1...

[AlvaroHN]

Update on this,

I ended up with a 20k pot in series with C2, and now I can adjust the ON TIME and there for adjust the "cut off" voltage of the dump.

best,

Alvaro

[AlvaroHN]

I have been playing with the comparator all weekend, trying to find the correct value capacitor for C2, because initially it didn't trigger with 0,1 uf, and I ended using 2.2 uf. But looking at the capture capacitor on the scope, I saw that it was dumping to the battery voltage, so the ON TIME was too much.

So I started to change cap values, etc, until I ended up with 3 little green caps (224k) in parallel (for C2) which dumped from 26 to 18.

For the capture cap I added another cap in parallel, 2 caps 3300uf 35v, total 6600uf. And I added a jumper to the positive rail of one of the caps to choose between 3300uf and 6600 uf.

The thing is that with 6600 uf the cap is discharged until 18 volts, and with 3300uf is discharged until 15.

It would be great to have a variable capacitor for C2 to change the ON TIME, but the variable capacitors are in the picoFarads range isn't?

And here comes the question---> Can I simulate a variable capacitor with a potentiometer and a cap in series???? While testing different cap values for C2 I saw that with a resistor in series would change the ON TIME.
I have also noticed that change in the "cut off" dump voltage depending on what I have for charging battery?, with my little lifepo4 it dumps from 26 to 18, with an old slab it dumps from 26 to 23, and with a alkaline 9v battery it dumps from 26 to 24. I guess it is because of the impedance of the battery.
best,

Alvaro

[AlvaroHN]

try it with the SG, you are playing with different electricity with the SG. I would expect the wall adapter to play nice with the comparator and operate in a linear fashion. how are you getting the required voltage? most wall adapters for computers are 24 volts on the output.

Tom C

I will try with the SSG and see.

I have an old HP wall adapter with 2 outputs 15 volts and 32 volts, so I use the 32 volts output to the comparator. the first time I connected the 32 volts directly to the comparator it started to dump super fast and I almost burn the BD243 that is before the mosfets, after that I added 400 ohms between the positive of the 32 volts and the positive input of the comparator.

best

Alvaro

[Tom C]

try it with the SG, you are playing with different electricity with the SG. I would expect the wall adapter to play nice with the comparator and operate in a linear fashion. how are you getting the required voltage? most wall adapters for computers are 24 volts on the output.

Tom C

[AlvaroHN]

Tnx for the answer Tom, mine is a 12 v system, and my cap is 35 volts, so I would be in a good range.

Strange thing what you say about adding caps in parallel and not affecting cap dump frequency. I did that and it slowed down the frequency of the cap dump, but I was not feeding the comparator with the SSG at that time, it was with a notebook AC/DC charger + resistance. I will try that with the SSG.

What you say about tesla nodes has been in my mind some days ago, I am going to put a small resistance coil with a FWBR in series between the output of the comparator and the negative of the charging battery and see what I can steal from there.

I also want to try the 1 wire thing that I saw in a John B video on youtube, where he shows that taking 1 wire from the output diode of the SSG and putting 2 diodes reversed in the end of that "1 wire" would pickup the energy and won’t affect the input. In that video he specifies the oscillator in 20Kc (20khz) so it might now work in my rotary SSG, but maybe it would work on a solid state.

best,

Alvaro

[Tom C]

cap voltage (its rating) I want it to be 2X battery voltage + 20 percent or so. so if you have a 24 volt system, 50 volt minimum plus 20 percent or so,. The big comparator JB builds is 4X 15,000 Uf 80 volt caps. like these http://tedss.com/2020031518 (oh today they are at a great price, last time I bought them they were 15 each) since the comparator dumps at 2X battery voltage approx., I want the cap to have plenty of room, but not too much. I do not want to spend time trying to stuff the cap completely full. remember the spike off the SG is 200+ volts, so headroom is nice.

I want to share something also, when I was running an comparator test in John's shop I asked him what would happen if we added caps, so we started stacking them in parallel. well the pulse frequency did not change even when we doubled or tripled the Uf value of the cap bank. the cap dumps at a fixed voltage ABOVE the battery voltage with John's circuit, the slower the dump is set the higher the cap is charged to. so you would think when you add caps it would take longer for the "bucket" to fill up meaning the voltage would not climb as fast, and the comparator would not switch as fast, or so you would think!

if there a point at which it slows down, I have not found it yet. the potential not captured by the capacitor is wasted, it just vanishes. proof to me is that more caps fill up at the same time from the same SG output. a single cap is not going to charge as well as 2 or 4 or 8. the same exact SG will charge a battery better with more caps, experiments must be done to see what the actual potential is in the spike. the advantage of the cap dump is it adds another radiant event.. what would happen if you added another coil and dumped into it and then into a battery? can you put tesla nodes on a cap dump? its the same phenomenon as the spike. what would happen of you ran a cap dump into a cap dump? or a cap dump into a coil to a battery or another cap dump.

sorry rambling a bit here...... take one aspect of the tech and run it to its extreme limit, then do the same with another aspect of it. if you watch the end of the Tesla switch DVD you can see John demoing an advanced version of a T.S. he does some calculations and shows how C.O.P. goes up wen the input current goes down. current destroys the dipole.

Tom C

[AlvaroHN]

not a simple answer...

https://www.physicsforums.com/thread...tially.618205/

Tom C

Tnx Tom for the link.

What is the relation (cap rated voltage / dump voltage) that you use?

best,

Alvaro

[Tom C]

not a simple answer...

https://www.physicsforums.com/thread...tially.618205/

Tom C

[AlvaroHN]

Brand new doubt: Does a 35v cap charges faster to 24v than a 25v cap??? (in the case that the 35v cap have the same capacity at 24v than the 25v cap at 24v)

I ask this because the cap charge graph starts fast and end slowly... maybe is better to charge the cap until a % of the total charge and it would be faster? or is the same?

best,

Alvaro

[AlvaroHN]

Just finished the comparator circuit. I had the same issue that lampliter14 pointed out with c2 (.1uf).

In my case I changed c2 to 2.2uf , with 100uf I had too much "on time".

My capture cap is small. 35v 3300uf.


Best

Alvaro

Pd: thank you RS for the circuit!!!!

[AlvaroHN]

http://sound.westhost.com/transistor-matching.htm

Thank you Tom !!! Have a great new year!

best,

Alvaro

[Tom C]

http://sound.westhost.com/transistor-matching.htm

[AlvaroHN]

How do I match the mosfets???

Finally I have all the parts for the comparator (RS_ snag 2 12 v). But I was wondering what is the right way to match the irfp260 ???

tnx

Happy new year to all!

best

Alvaro