This circuit was found in a 90s Popular Electronics. The circuit uses components from that time, intended to receive signals in the range of 150 to 250 kHz.
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...