This circuit identifies the polarity of DC signals and if the signal is AC. The circuit is from 1969 US EDN documentation. Operational may be equivalent.
The integrated circuit used in this 80's mixer is the LM301A. However the circuit can be used to...
This circuit, found in a 1982 documentation, consists of a small inverter based on a Hartley...
Found in Popular Electronics from the 90s, this circuit powers a warning lamp when the load is...