cap dump schematic questions

[Faraday88]

Hello again Gary,

I forgot to add another question to my last message. It's regarding the recovery coil. I think I get it, but I just want to confirm. In my case, I have 8 power windings. All I need to do is isolate out one of them right - and then hook the diode to the bottom end (would a 1N4007 work?) the cap to the top end, etc. as shown in the schematic?

By-the-way, Aaron told me a comparator circuit is better, but that it's more advanced and may be a bit much at my stage, since I'm new at circuit building, so that's why I opted for this one. Since I'm living in Costa Rica and have already ordered everything from the states, I'm basically locked into this method for now.

Hi,
There is nothing Advance of anything unless you find it out on your own!.. the comparator is a device that auto triggers when the set Voltage is reached,that you can manually set with the pot in the circuit arrangement.
Rgds,
Faraday88.

[Cmor]

Another question

Hello again Gary,

I forgot to add another question to my last message. It's regarding the recovery coil. I think I get it, but I just want to confirm. In my case, I have 8 power windings. All I need to do is isolate out one of them right - and then hook the diode to the bottom end (would a 1N4007 work?) the cap to the top end, etc. as shown in the schematic?

By-the-way, Aaron told me a comparator circuit is better, but that it's more advanced and may be a bit much at my stage, since I'm new at circuit building, so that's why I opted for this one. Since I'm living in Costa Rica and have already ordered everything from the states, I'm basically locked into this method for now.

[Cmor]

Hi Gary,

Thank you.
I appreciate the clarification of what the voltage regulator is doing. I was clear on the function of the optoisolator, but confirmation is always welcome.
I still remain a bit confused about the switch though. Do you mean, rotating the wheel is the "switch" or is there something physically there, in that part of the circuit, that I need to install?

[Gary Hammond]

Hi Cmor,

The voltage regulator supplies a constant 12 volts to both the BD243C transistor and the H11D1 opto coupler thru the leg going to the right. And no, the regulator doesn't trigger the transistor. The opto coupler keeps the run battery completely isolated electrically from the capacitor, 7812 regulator, DB243C transistor, IFPR260 FETs, and the charge battery.

The 555 timer circuit causes the 2n4401 and 2n4403 to trigger the H11D1 opto coupler which in turn triggers the transistor. The capacitor is discharged thru the FETs when the transistor turns them on. The timing of the 555 therefore determines when the cap dumps rather than comparing the voltage on the cap to a given value. A comparator circuit is actually a better way to do a cap dump.

The switch you were asking about is simply and on/off master switch for the entire device.

[Cmor]

the new schematic and my original questions

Thanks RS.

So it seems the voltage regulator is now both turning on the transistor, and sending the current through it, instead of the current coming from the battery as before.

It seems more certain that the leg of the voltage regulator going to the right is output, but can you confirm?

Any comments on the switch I was asking about?

[RS_]

here is a corrected version of the Sch

[Cmor]

I have a couple basic questions about the attached schematic for creating a cap dump (from p. 47 of the intermediate handbook).

A switch is shown (I've circled it in red and labelled it) between the positive post of the run battery and two other circuit branches, one going to the top of the main coil, the other going to the 555 chip circuit. I’m assuming there’s no physical switch there, and that it’s just an area that functions like a switch. Can anyone confirm this for me? I want to make sure if there’s a part I need to buy, I get it.

Incidentally, the reason I can conceive of it as a virtual switch is that when the battery is pulsing current it would “close” the return path from the main coil to the battery positive, and when the battery isn’t pulsing, it would “close” the return path for current coming from the 555 circuit. Is this correct?

Another question is about the 7812 voltage regulator. I’m assuming the leg shown on the top, closest to the number 7812 is input, the one going out to the right is output and the other is ground (I've labelled them such to clarify my question). Is that correct?

There’s a diode between the recovery coil winding and the capacitor and voltage regulator. It’s a single diode as opposed to a bridge rectifier which is in the older schematics. Would a 1N4007 work? If not, what diode should I put there?

When the magnetic field in the inductor collapses, I’m assuming the back EMF goes out through the recovery coil along with the radiant spike (instead of going back into the run battery). Is that right?