This circuit was found in a 73 magazine for radio amateurs from the 90s. The circuit uses high voltage transistors and the relay is high voltage as well.
The Texas Instruments TPS80 LDO (Low Dropout) series (www.ti.com) can provide output voltages from...
We do not need to stress the importance of power supplies in the project development laboratory or on the...
This circuit, found in documentation from the 1990s, uses a common 7-segment LED display. The...