This continuity test was found in a 90s Electronic Engineering. Transistors are types of general use of the time with equivalents such as BC548 and BC558.
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...