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 long delay circuit was found in the July 1973 Radio Electronics magazine. The capacitor...
This basic circuit showing the LM3914 “inside” was published in the October 1980 issue of Radio...
Using only one general purpose transistor this circuit is powered by batteries. The lamp of the...