Found in Motorola documentation from the 1970s, this circuit makes use of period components. The lamp is used as a stabilizing device. The signal is sinusoidal.
With this luminous remote control, which we found in a 1990 publication, using a flashlight you...
We found this circuit in a 1967 Electronics World. The circuit can be designed to control other...
This circuit can be used in a signal level indicator with LEDs. The circuit is from an Electronics Now...