#782 555 Compact LED Flasher

An unusual configuration of the 555 produces an astable oscillation with minimal, small components.

Here’s a quick demo..

Notes

Franz Bachler designed the LED Flasher circuit as seen on Talking Electronics.

The design has the distinct advantage of only requiring two resistors and a low value capacitor - components that may be compressed into a very small package. Ideal for discrete blinking LED circuits.

Steve Schnepp also wrote about the circuit (Minimal NE555 Blink) and found the idea referenced in the TI LMC555 datasheet.

Circuit Design

Designed with Fritzing: see CompactLEDFlasher.fzz.

The circuit can work from as low as a 3V supply, but 5-9V gives best results (without adjusting R2).

Credits and References

• LM555 Datasheet
• TI LMC555 datasheet
• Visual 555 Calculator
• Reference Circuits:
  • LED Flasher on Talking Electronics.
  • Minimal NE555 Blink