This circuit was found in a 1980s documentation. The diodes may be general purpose diodes such as 1N34 or 1N60 and the indicator may be the lowest current range of a multimeter.
This circuit is from 1992 documentation. The transistor can be a TIP42 with a good heat sink for...
The circuit we present is suggested by Linear Technologies (www.linear.com) and makes use of an...
We find this ultra-simple transmitter circuit that is nothing more than a very short range RF...