Raystor is a component of the 1960s Raytheon. It consists of a light coupler that allows you to use the circuit as a DC control for signals as shown.
This current meter with many scales was found in a 80s American documentation. The operational amplifier...
This 90s Motorola circuit from, has current limiting foldback. The power transistor is from the...
This circuit was found in an Electronic Design from the 90s. The shapes of the signals obtained as result...