Using only an ultra-bright white LED, red blinking LED, PNP transistor, and a diode, the circuit gives a strong visual indication of current consumption by blinking brighter and more frequently as ...

Microcontroller projects often light up an LED, too, and a blinking LED is something of the “hello world” program for embedded systems. ... In this circuit, a PNP transistor sources current.

This simple and cheap circuit is not just for Christmas! There are just two resistors, a small-signal transistor such as a BC547, one ‘flashing’ LED and a string of ‘normal’ LEDs. The flashing LED ...