This circuit is from an American documentation from the 90s. The transistors are of power and must be equipped with good heat sinks as well as the integrated voltage regulator.
This circuit was found in Philips documentation from 1967. The phototransistor is from that time,...
This source gently applies the voltage to the load, causing it to rise slowly, thus avoiding...
We found this adapter in a 1970s American documentation on instrumentation. It is suitable for analog...