Make:

Dave writes in -

I wanted to see how few parts I could use, from what I had on hand, to build this clicking blinking LED device based on a 555 chip.

This article was submitted by Lee Bornifield as part of the "Hobby parts for articles " program. Write something of interest to electronic hobbyist and receive parts for your next project.

Probably the most expensive part is the 9V battery. There is no circuit board, and no additional wires; just bending the leads of the components provides enough connections.

The earphone clicks and the red LED blinks at a constant 137 times a minute. The exact rate depends on the value of the resistor and capacitor. That rate will be maintained very precisely for the life of the battery. It's not forever, but listening closely I could still hear the earphone faintly clicking after 6 days of continuous operation.

Related:

555 timer - five boro bike tour time lapse- Link.

555 timer origami- Link.

More 555 timer projects- Link.

41 LED Flasher circuit using 555 IC- Link.

From the pages of MAKE:
The Biggest Little Chip. MAKE 10 page 62. An introduction to the versatile 555 timer. Subscribers--read this article now in your digital edition or *BLOG SPECIAL* subscribe to MAKE (use code CMAKE for $5 more off USA + free digital edition!).