Kapanadze Cousin - DALLY FREE ENERGY

[verpies]

@Itsu

I just realized that you had your yellow probe in the input of the MOSFET driver, not on its output.
What happens when you increase the drain power supply to +200V and scope the power supply pins of U3 ? 
Do you still have pure DC between U3 pins 14 and 7 ?

[verpies]

As mentioned before the frequency can be varied between 6khz up to 200khz with a maximum of 40/60 duty cycle.

But at what frequency did you have that light bulb connected as load and the current taken from the source at 4.5A ?
150kHz or did you mean that it stayed at 4.5A BETWEEN 6kHz and 200kHz ?

The transformer I'm using it's taken from a computer power supply. I cannot provide any tech specs regarding it.

What about the inductance of the primary winding of this transformer?
If you do not have an inductance meter, at least write us the current slope (di/dt) in the primary winding without any load on secondary, as shown on your scope.

Variations from Dally's unit:
MJE13009 replaced by some 2SC9245 (I'm not at home and I don't remember exactly). The main difference it's the power dissipared by the 2SC....-80W
2N5401 replaced with BC327
TL494 supply line has a 7812 regulator with some caps for better filtering.

That's clear enough

As expected increasing the frequency and the duty cycle light the bulb brighter and brighter. Maximum was obtain around 150khz and 40/60 duty cycle.

Was this most efficient 150kHz frequency determined during a sweep while the Du.C. was kept constant?

[itsu]

@Itsu

I just realized that you had your yellow probe in the input of the MOSFET driver, not on its output.
What happens when you increase the drain power supply to  200V and scope the power supply pins of U3 ? 
Do you still have pure DC between U3 pins 14 and 7 ?

Well,  not really, 5V DC with the same nasty ringing, (yellow probe across pins 7 and 14) see picture:
(by the way, i now have a 10 Ohm resistor across gate-ground of the MOSFET)


Meanwhile i tried to find the saturation point of the small toroid, but probably my 0.1Ohm resistor is too inductive as i see a lot of ringing on this CSR.
Video:  http://www.youtube.com/watch?v=Xvq5FV6SC1A&list=UUdJ2A-075yx9y4bKqu_8Q8A&index=1&feature=plcp

Guess i have to find me a suitable CSR first.

Regards Itsu

[mihai.isteniuc]

But at what frequency did you have that light bulb connected as load and the current taken from the source at 4.5A ?
150kHz or did you mean that it stayed at 4.5A BETWEEN 6kHz and 200kHz ?

At 150KKz the light bulb was the brightest and the current taken from the source was 4.5A

What about the inductance of the primary winding of this transformer?
If you do not have an inductance meter, at least write us the current slope (di/dt) in the primary winding without any load on secondary, as shown on your scope.

I will post some pictures. Also I will connect a condenser in parallel with one of the primaries and try to determine the inductance based on the ringing frequency. I can tell you that the primaries are made from 3 parallel wires at around 0.5 diameter. That can be seen near the connection pin of the transformer.

Was this most efficient 150kHz frequency determined during a sweep while the Du.C. was kept constant?

Yes that is correct

Mihai

[verpies]

Well,  not really, 5V DC with the same nasty ringing, (yellow probe across pins 7 and 14) see picture:

Aaaaaa, get rid of it!
Supply must be pure DC.  You already know the drill: bypassing capacitors in parallel, small thick-wire chokes (or ferrite beads) in series, starpoint ground and power distribution.

(by the way, i now have a 10 Ohm resistor across gate-ground of the MOSFET)

Did it worsen the offâ†'on transition of the MOSFET much ?

Meanwhile i tried to find the saturation point of the small toroid, but probably my 0.1Ohm resistor is too inductive as i see a lot of ringing on this CSR.
Video:  http://www.youtube.com/watch?v=Xvq5FV6SC1A&list=UUdJ2A-075yx9y4bKqu_8Q8A&index=1&feature=plcp

I'll watch it as soon as YouTube resumes working.