This ultrasonic digital remote-control transmitter was found in the January 1976 issue of Radio Electronics magazine. The components are from the period. The IC is from the period.
This circuit triggers the LED when the monitored battery voltage drops below 9 V for 12 V...
We found this circuit in a Radio Electronics from January 1967. The SCR is already the C106, which...
This power source with silicon diodes at a time when valves were still used was found in Radio...