This crystal tester was found on a 90s Ham Radio. Transistors are commonly used. The circuit is for testing crystals from 2 to 20 MHz.
In the circuit in the figure, when a pulse of light falls on the LDR, the circuit arms with the...
This switched or switched regulator was suggested by Texas Instruments in one of its application manuals....
Using transistorized regulators with NPN and PNP transistors we can create a symmetrical source of...