We found this multiple thermostat circuit in July 1980 Radio Electronics magazine. It uses opto-triacs for power control and operates on a 117 VAC mains.
Found in a 1964 General Electric documentation, this circuit uses PUTs that are not currently...
This double tone generator uses a specific integrated circuit, having been found in a 1977 CMOS...
Found in American documentation from 1968, this circuit has an acute cut-off of the frequency to...