This power supply protection circuit using a relay was found in a 1967 documentation. The components are from the time, but current equivalents can be used depending on the power source current.
This circuit detects the phase of a signal. As it is a TTL circuit, it must be powered by a...
This oscillator for practicing code with a transistor was found in Popular Electronics. The...
This high-power flasher for incandescent signaling lamps was found in a 1980s General Electric...