Suggested by General Electric documentation from 1968, this circuit activates a relay after 60 seconds, keeping it closed. PUT is an uncommon component today.
This circuit is from a Popular Electronics from the 90s. Its gain is 22 dB and can be used as a...
This Rytron transmitter was published in a 1953 book. The circuit can be implemented with a BC558...
The purpose of this circuit is to keep the other phones on the same line muted when one is used....