555 Timers
It is not normally our policy to quote other web pages, we just link to them. This may be reverted to just a link. What do other admins think? --russ_hensel 01:46, 18 January 2010 (UTC)
The 8-pin 555 timer is one of the most popular Integrated Circuits (ICs) ever made.
It is also one of the cheapest chips on the market, costing anywhere from $0.20 to $1.20 depending on the quantity and distributor.
The 555 timer will operate from a power supply of 4 V (some versions even less) to about 16 V. The 14-pin 556 timer contains two 555 timers in a single package -- the two timers (A and B) share the same power supply pins.
Astable - producing a square wave Monostable - producing a single pulse when triggered Bistable - a simple memory which can be set and reset Buffer - an inverting buffer (Schmitt trigger)
For more details on a variety of circuits that can be built using a 555 timer, see
