Light test (CB8789E)

This light-sensing probe was found in a 90s Popular Electronics. The circuit detects light sources by triggering a buzzer.

Optoelectronic Assisted Ignition (CB19873E)
This circuit was found in documentation from the 1980s. The control pulses are obtained by an...
5V x 10A Regulator (CB16992E)
This high current regulator for TTL circuits was found in an old French documentation from the...
20 LED voltmeter in second version (CB25458E)
This circuit is an alternative to the previous circuit. We found it in the same article in the...