We found this circuit in American documentation from the 1980s. Transistors can be of general use. The frequency range of the generated signals ranges from 500 kHz to 10 MHz.
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...