Cgs synth

Thanks for the input!

You where right at assuming this:

> 2) Maybe you did not have one with a high enough rated voltage.

The Tant was 16V. No wonder it went ka-boof.

> 3) Tants do that for no apparent reason from time to time. I refuse to use the nasty things myself. Use regular Electros with a minimum rated voltage of 25V.

I didn't know that! I'll refrain from using them for power tasks but I might prefer them when low leakage is at the essence, like steady timing. Also, I opted to leave out this cap from the circuit, since it was a problem area. The two other electros seem to cope quite well.

> Do NOT power CMOS on 18V - that is beyond their maximum rating and usually results in the chips going the same way as the Tant.

OK, I let myself mislead by the datasheet for the cmos chips. They say working voltage is 5V to 15V but that absolute max rating is quite a bit higher. Therefore, I assumed, they would cope. I still use the 18V line since this is my "dirty" supply rail. For safety, I have clamped the input down with a zener and resistor.

>> there is still a short.

...not anymore. After rewiring most of the power input parts of the board, i.e. the traces around the electros, it finally works like a charm. The need for that was not down to a poor quality board but poor desoldering skills. I made it shed copper like crazy. What a labour of love that was! My first successful troubleshoot. Next in line: the CGS35. Wish me luck :0)

> If the chips are socketed, remove them from the sockets before you go short hunting again.

What a fabulous way of putting it. I sure did. Very valuable insights you shared, Mr Stone. I learned a lot from this

Tor Olav