This circuit for incandescent lamps was found in a 70s documentation. The circuit uses an SCR according to the power of the controlled lamps. The delay is a few seconds, given by capacitor C1.
The setting of this power supply is only 0.1%. We found it in a 1969 US documentation. Transistors...
We found this interesting transistor generator in European documentation from the 1980s. The...
The circuit shown in the figure uses two of the four operational amplifiers found on the LM324...