This circuit is from a 1978 Texas Instruments optoelectronics manual. The trimpot adjusts the LED current. Other currents can be adjusted if they are within the capacity of the FET.
This oscillator circuit for sinusoidal audio signals with operational 741 requires a symmetrical power...
Found in a 1974 Radio Shack documentation. This circuit must have a connection to the ground of...
This sensitive circuit detects the live pole of a power grid or outlet. The circuit makes use of a high...