Constant current source (CB20484E)

This circuit uses a current regulator from the 90's. This component is uncommon nowadays. The transistor admits equivalent.

Locked Alarm (CB4872E)
This simple circuit uses an SCR to lock the alarm once triggered. The circuit is from an English...
LEDs in 110 V or 220 V (CB499)
The figure shows a simple circuit to power LEDs from the AC Power Line. The resistor can be a wire...
Relaxation Oscillator Using PUT (MSB075E)
This is a simulation of a Relaxation Oscillator using a programmable unijunction transistor (PUT). The...