This circuit is from a 1965 Radio Electronics. The triggering transformer generates high voltage pulses. The generated light pulse depends on C1 and C2.
Using SCRs, this circuit from a 1967 General Electric manual allows full wave load control with SCRs....
This interesting circuit from a publication from the 1970s, measures the intensity of the sound...
This simple NPN and PNP transistor tester configuration can use the low current range of a common...