It normally takes two transistors to build a blinker circuit (in order to make positive feedback possible). However, you can also use a photo-resistor (LDR) that is illuminated by an LED. The feedback ...

These days, if you want to flash some LEDs, you’d probably grab a microcontroller. Maybe you’d go a little more old-school, and grab a 555. However, [Jacob] is even more hardcore than that, as ...

This circuit was designed to provide that continuous light lamps already wired into a circuit, become flashing. Simply insert the circuit between existing lamp and negative supply. Especially suited ...