This sample and hold circuit is from a 1969’s documentation. However, it can be built with modern equivalent components, including the matched pair of transistors.
This circuit simulates an inductor. Or operational amplifier of old type, but a configuration is...
We found this circuit in a 1967 Electronic Design. The circuit uses contemporary transistors that...
To control relays safely with double insulation, we suggest the circuit in the figure. The optical...