Found in Motorola documentation from the 90s, this circuit makes use of a triac from that time. The circuit is for the 110 V mains but can be modified for other grid voltages.
In the figure we have a Texas Instruments circuit for TTL interfacing using discrete transistors. The two...
This circuit was found in Radio Electronics magazine from June 1963. The range is small and the...
The project presented in a 2009 documentation is intended for radio amateurs operating in the...