Found in a 1967 General Electric documentation, this meter uses Nixie tubes, popular at a time when LED and liquid crystal displays did not yet exist.
This circuit is used to cut the “click” in the loudspeaker of amplifiers when they are turned on....
Found in RCA documentation from the 1970s, this circuit is intended for firing thyristors in inverter...
In the figure we have the way to control a TIC series triac with a reed switch. The current in the...