This optically coupled circuit was found in the February 1968 Radio Electronics magazine. The circuit uses an LDR in modulation. Transistors are types of the time.
This circuit was found in Maxim documentation from the 1990s. The RC circuit determines the...
This Vienna bridge multi-band oscillator circuit was found in a 1974 Ferranti transistor manual. The...
This circuit can be used as a shield to control the matrix flow of 100 LEDs from a single output of...