We found this circuit in the 1957 Raytheon transistor application manual. The transistor can be a BC558 and the common 6 V relay, just by using this voltage in the supply.
The components used in this National Semiconductor circuit are not common today, but the...
This 2001 circuit is used with transceivers to increase the gain of a microphone and thus obtain...
In the figure we have the configuration of a variable voltage regulator with two transistors and a...