We found this circuit in a 1968 General Electric publication. The circuit uses an SCR of the time, but any modern equivalent can be used. The relay must have contacts that support the horn current.
We found this circuit in a 1997 documentation. Its purpose is to fan an inverter for fluorescent lamp...
The figure shows how to implement a conventional current monitor with differential amplifier on an H...
This is a circuit using the DM31O0UI digital module. We found it in an article in the Radio...