AVR-Doper problem with HVSP

[Treito]

Hello,

I managed to build the AVR-Doper, but on the cathode of D3 I get only 4.3V. Changing R5 has also no effect. T2 is getting very hot. What is wrong?

Regards,

Sven

[Treito]

Okay, something has to be wrong. I increased the inductance to 40mH, changed R18 to 100 kOhms and now it works. My two dead Attiny44 live again!

What's wrong? Are there any differnces with the inductors and the magnetic field?! Do I have a wrong type of inductor?