We found this simple protection with zener diode in a 1967 Motorola documentation. The zener diode is 18 V, but the components can be changed for operation with other voltages.
This simple 1 transistor circuit was found in an American documentation from the 60's. The...
Found in a magazine 73 for radio amateurs, this circuit makes use of general purpose transistors and...
The presented circuit allows to control the valve of a tap. The positioning of the emitter and the...