We found this circuit in a 1967 American documentation. It is a transmitter for animal research, monitoring intestinal pressure. The operating frequency is 22 kHz.
The circuit presented may use any general purpose transistor. The indicator is an LED and...
This source was found in a 1982 American publication, but can be easily assembled using 2N2995 (PNP...
Found in a 1980s documentation, this circuit uses as base a component of the era. The formula for...