This circuit was found in a Popular Electronics from the 90's. The transistors are general-purpose types and the loaded load depends on the voltage and must have a maximum current of 100 mA.
May 2016 - It can be obtained from Mouser Electronics new tricolors chipsLEDs from Broadcom for...
This circuit for shunt motors was found in an American 1980s documentation. The SCR should be rated...
This circuit was found in a 90s Popular Electronics. It generates tones given by the oscillators and...