Found in a 90’s Electronics Now, this circuit has its output connected to an audio amplifier. The transducer is the type that fits on the finger to monitor the transparency and thus the beats.
We found this circuit on Radio Electronics from July 1990. It triggers a relay with a touch of the...
In the figure we have a configuration that allows to test NPN transistors and with the addition of a...
The figure shows how to implement a No – OR or NOR function with 1 general purpose transistor. The supply...