This circuit with 1% regulation aims at replacing mercury cells. We found it in a 1967 documentation. Transistors can be replaced with modern equivalents.
This logic circuit can indicate both TTL (5 V) and CMOS (5 to 12 V) output levels, operating with...
This sonic relay circuit is driven by a high-pitched sound picked up by a microphone that can be a...
This circuit monitors the activation of a lamp or other load through parallel or two-way switches. The...