Bedini Comparator Cap Dump

[Tom C]

not a simple answer...

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

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]

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]

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]

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]

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

[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]

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

[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...

[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]

Your right Tom!....Stilll i always wandered how the cap is able to dump 70A/sec ...advanced book says that...and if we'r using the same power in/out and amps to charge the batt.then whats the advantage?pulsed amps?

[gabiX87]

Hi everyone,

currently sourcing the parts for the 12V comparator circuit which RS_ posted (KRL RS revB, 08/12/14). I have a couple of questions guys. I have no formal electro background , just a self learner.

There are a lot of information in specs sheets which I cant interpret , need some help.

1. I have all the resistors but I have problem to find D3 1N5242 12V Zener .... can I use 12V/1,3W = BZX85C12; 1N4742A ?
2. Also none of the supplier have exactly LM741 ,they do have with different specs. Will these do ? LM741CH/NOPB (1MHz; 3÷18VDC; TO99) or LM741H (1MHz; 10÷44VDC) or UA741 CN = LM741 CN (DIP8) (1 MHz ,Supply Voltage Min 5 V , Supply Voltage Max 40 V )

3. Also there are variations of IRFP260 MOSFET ... I suspect the higher the A rating the better for cap dump. I have some 3x or 4x IRFP260MPBF (HEXFET; 200V; 50A; 300W) Will these do ?
or I can order these AUIRFP2602 Transistor: N-MOSFET; unipolar; 24V; 380A; 380W; TO247AD

4. The capacitors should all be electrolytic ? Do all caps have to have the same Voltage rating ?

Thanks for help
Gabriel

WHY THERE IS NO STRIKE-THROUGH FORMATING/OPTION TO STRIKE TEXT BUT NOT REMOVE IT.

[James McDonald]

Hi everyone,

currently sourcing the parts for the 12V comparator circuit which RS_ posted (KRL RS revB, 08/12/14). I have a couple of questions guys. I have no formal electro background , just a self learner.

There are a lot of information in specs sheets which I cant interpret , need some help.

1. I have all the resistors but I have problem to find D3 1N5242 12V Zener .... can I use 12V/1,3W = BZX85C12; 1N4742A ?
2. Also none of the supplier have exactly LM741 ,they do have with different specs. Will these do ? LM741CH/NOPB (1MHz; 3÷18VDC; TO99) or LM741H (1MHz; 10÷44VDC) or UA741 CN = LM741 CN (DIP8) (1 MHz ,Supply Voltage Min 5 V , Supply Voltage Max 40 V )

3. Also there are variations of IRFP260 MOSFET ... I suspect the higher the A rating the better for cap dump. I have some 3x or 4x IRFP260MPBF (HEXFET; 200V; 50A; 300W) Will these do ?
or I can order these AUIRFP2602 Transistor: N-MOSFET; unipolar; 24V; 380A; 380W; TO247AD

4. The capacitors should all be electrolytic ? Do all caps have to have the same Voltage rating ?

Thanks for help
Gabriel

Hi Gabriel --

For the 12 Volt Zener use the same part number with a "B" added on the end. 1N5242B.
For the 741 I used the better rated one which has a 44 volt swing. Which means the max
+/- voltage is 22 volts.
For the FET's it really depends on how much current you capacitors are going to store before
you let them dump. I used a part that was rated at 200 volts @ 130 Amps. The IRFP260MPBF
will be fine if your capacitor total is not to big.
It is best if all the capacitors are rated at the same voltage. I used four totaling 88,000 ufd.
The voltage rating was 63 volts. See my completed board assembly running on AC house
current. It also works off the back of the SG Machine.



James McDonald

[gabiX87]

RS_ has exceeded their stored private messages quota and cannot accept further messages until they clear some space.

Jame McDonald
thank you much for the pic. I redraw the SNAGs-002 diagram back to Altium Designer and my friend will help me with PCB design and milling.
By the way do you have *.PcbDoc or *.SchDoc of yours ? Would help a lot ,I have issues with parts library in altium. The schematic is ok , but the PCB part ,oh boy...

Thanks
G

[RS_]

gabiX87

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