Rob said:
that seems to be a trend in any of the high-technology fields, about 10-15 %
with low level knowledge and design understanding where the other 85-90 %
are component users/tinkerers/builders.
We used a pnp and a npn in a astable flipflop (advantage,both
tansistors open/closed at the same time.) running on a 4.5 flat
battery,and a small speaker as collecror resistor in one side.
the other side had the timer resitor and the plus battey connected
to 2 test leads. Makes a very nice audio resitance/voltage tester.
No on/off switch,battery stayed alive for about 4 years.
With the testleads open, both transitors remained closed,so only
leaking current.