This circuit was found in a Philips documentation from 1966. The circuit provides 1 mW with a power supply of only 1.3 V. Transistors support current BC series equivalents.
In the figure we have the way to increase the current capacity of an operational amplifier. The...
This different circuit uses a relay as an oscillator, whose frequency is determined by C1, and to...
The circuit presented makes use of the LM340 and a power transistor that can be the 2N2955 or more...