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.
Found in Raytheon's 1960s transistor circuit manual, this circuit employs the CK722, one of the...
Found in Electronics now, this circuit generates signals given by the formulas next to the...
Found in Popular Electronics from the 90s, this circuit can be used as a warning shield for...