Withoutbattery
Withbattery
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.

uC Hobby » Blog Archive » LM555 Tick tick tick – Link.

Related:
Img 5400M-1
555 timer – five boro bike tour time lapse- Link.

Folded Timer555
555 timer origami- Link.

Timerfig1
More 555 timer projects- Link.

Img 5400M-2
41 LED Flasher circuit using 555 IC- Link.

Make 654
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!).