We had found this circuit in a January 1961 Radio Electronics Magazine. Using it is possible to take measures from the gain of transistor with a common a multimeter.
This circuit uses a small photocell to trigger an auxiliary flash. The circuit is from a 1991 PE...
A touch of the X1 sensor causes the motor to be activated for a time that can be adjusted in P1....
This circuit allows the division of the frequency generated by an oscillator with the 4069 by two,...