Akula0083 30 Watt Self Running Generator.

[TinselKoala]

thanks, e6, that is helpful

I see the two strings of 5 each LEDs under the words "HL 15V" , and if they are 3V LEDs then yes, 15 volts will be needed to light them. But at only 60 mA or so, I think, and that is DC. If the thing does what I think, which is to make higher voltage, short durations spikes, then the current could be higher, but again, short term.

So where does the "30 Watt" output figure come from? DC power to light up all the LEDS to full brilliance and maybe beyond,  should be less than one watt. Are they special LEDs, high-power high brightness ones?

[TinselKoala]

Look. When the 12 V battery is connected and the "start" switch is depressed, the the C11 cap is charged right away and the C3 capacitor is also fully charged through the current path thru the unlabelled diode near the switch, the first "L1" coil which must be the toroid, the 0R22 resistor R1, the other "L1" coil which is the transformer primary, and the first high-current Schottky. This is the reason that diode must be able to handle high surge currents. This same path also includes the second Schottky, the secondary of the transformer, and back through the NC "stop" switch to help charge the other large cap C11. This same path also includes the output LED bank in parallel with it, so the LEDs light up too if the supply battery voltage is high enough. It must be over 12 volts anyway or the 7812 regulator does nothing, it can't regulate "up", just down. None of this current path involves the 494 chip or the 7812 VR at all, and the two charged caps will keep the LEDs lit for a little while (I don't know how long yet) after the Start switch is released and before the Stop switch is pressed.
I think.

[TinselKoala]

When the 494 starts oscillating this will affect the DC current path outlined above and the transformer will now start making spikes of higher voltage. This will charge up both big caps through their Schottkys, but the LED bank will keep the voltage from going too high on the caps, I think. If the 494 keeps running it is running on these two capacitors but I can't see how it would keep running for long, once the "start" button is released.

[Dave45]

L1 is pulsed by VT1, the bemf from L1 runs through D1 and D2 into L2

Basically the same thing that happens in V8carlos's circuits, one coil gets a neg pulse the other a pos pulse.

[TinselKoala]

There are some rather large differences between that schematic and earlier ones in the thread. But at least it uses a correct symbol for the mosfet.

The LED is wired differently, the output of the 494 is done differently and the mosfet gate driver is completely different. The gate driver shown in this circuit is probably better than the ones in the other diagram. I don't know about the different connections to the 494.

However the DC current paths I described that charge up the two large capacitors are still as I described them.

As long as you cannot agree on which circuit diagram is actually to be used, there isn't any point in me building anything, I'll just go back to lurking. Where are the big diodes in the photographs that are below the schematics, for instance?