This circuit automatically turns off small battery-powered devices after a certain amount of time, saving battery life. We found it in a Popular Electronics from the 90s.
We find this circuit in American documentation from the 1980s. The accuracy of the circuit depends on the...
The presented circuit uses a symmetrical power source to supply an amplifier with the LM139 or...
High quality sound can be obtained from this transistor amplifier. The output transistors must be...