Found in a 1980s documentation, this circuit uses transistors from that time. Modern equivalents can be used. The alarm is a piezoelectric buzzer with na included oscillator.
This circuit can be used to test zener diodes up to 25 V using a standard multimeter. The voltage...
This TTL traffic light circuit was found in an English magazine from 1977. The magazine no longer...
This circuit is from National Semiconductor documentation. The operational amplifier is of the...