We found this circuit in the 1983 Radio Electronics Special projects magazine. The components are common, and the circuit drives a relay. The power supply must be isolated.
This pocket radio for the medium wave band was found in the Radio Electronics magazine of January...
Other operational amplifiers of the same series can be used on this circuit found in Motorola's Linear...
This is the normal configuration of the LM12 as a high voltage amplifier. The LM12 consists of a...