This circuit can be implemented with common components operating with low-intensity signals. The circuit was found in the April 1987 issue of Radio Electronics magazine.
This timebase was found in a European 1980s documentation. The circuit uses well-known components...
This amplifier stage with 1 power transistor was found in the Radio Electronics magazine of...
The basic idea of this 1989 circuit is to trigger a relay for a while when a call signal occurs on...