Found in the July 1994 Electronics Now magazine, this circuit drives a relay up to 12 V depending on the power supply. The transistor can be general purpose.
In the figure we have the circuit of a millivoltmeter with operational Amplifier using a TLC271...
This receiver was found in a Japanese publication in 1967. The circuit uses germanium transistors and...
In this circuit of 1987 the player has to briefly press one of the keys trying to hit which LED...