Found in General Electric's documentation from 1970, this circuit is indicated for the so-called “Solid State Lamp” (SSL). The LED symbol in the original diagram is inverted.
We found this circuit in a publication for radio amateurs in 1974. The bipolar transistors can be...
Found in a 1980s American documentation, this circuit has a current consumption of only 1 mA. The...
This adjustable power supply was found in Ferranti's transistor manual from 1974. Power...