This circuit was obtained in a 1969 Mullard manual. The transistors are from that time. The input sensitivity is 300 mV.
Currents of a few tens of milliamps can be obtained with this simple source that makes use of an...
This circuit was obtained in a 1990 English magazine. The circuit can be assembled with equivalent power...
This circuit is recommended by Texas Instruments in the datasheet of the TL317, equivalent to...