mystery
ZXNet echo conference «hardware.zx»
From Kirill Frolov → To All 8 September 2001
Press RESET immediately, All!
There is a diagram: KT315 and KT361 two transistors, collectors together,
emitters on GND and 5 volts. The bases are connected together through ~1k resistors
and ~100Khz meander is applied there. An electrolytic is connected to the collectors
capacitor ~10 µF, after it there are two diodes and another capacitor at the output.
This is to make a negative voltage from +5v - I hope the circuit
imagine. So at the output (and there is a load - a microcircuit)
there is a negative voltage of -4.5 volts. I forgot to say that
diodes used type KD522.
So the question is - how do you get -4.5 volts at the output when powered?
+5.09 volts? If you calculate the voltage drop across 2 diodes and 2
THIS CAN'T HAPPEN WITH TRANSISTORS!