Re: Aw: [EVGRAY] Re: Push pull generator.

Body

Hi Sven,

The capacitor in parallel to the parasitic gate-source capacitor can be omitted if using a low impedance gate driver placed close to the MOSFET for minimizing inductive loops. Twisting the gate source wires forms a transmission line of less impedance than the big loops on the picture. Twisting the wires of different gate circuits together couples them together. This can be seen in the scope shot where spikes are transferred between the two gate circuits. This also happens between the big loops that work as loop antennas which both send and receive the signals. See the picture below if it makes it through Yahoo.

"For me, C1 is 1μF MKP and C2 is 68μF Elko.
R2 2.2 ohms and R3 now 10K."
This doesn't tell anything without knowing how or what they're connected to.

Regards
Ole
 

---In [email protected], <s.friedrich@...> wrote :

 Hello Ole,

I looked at the PDF and added one from Toshiba where on the last page you should put a capacitor between gate and source, I used a very small one with 10nF.


For me, C1 is 1μF MKP and C2 is 68μF Elko.
R2 2.2 ohms and R3 now 10K.

I've twisted all the wires and connected, unfortunately, I can not keep the lines so short by my design, but I only work with frequencies from 37 to just over 600 Hz.

I send some Scope pictures I have the feeling that the Mosfet switch clean and the small disturbances do not affect them, at least if you look at the scope pictures from the power section.

What surprises me is that my Scope probably disturbances in the system brings at least at small pulse widths a signal from whatever. The scope is grounded if there are leakage currents flowing over it?!?

regards

Sven