This experience on applications Ic555 and tells about how to use Ic555 the radio circuits.
You may not know his name, but you've encountered Hans Camenzind's designs countless times. Hans was one of the rock stars of the integrated design world, with 20 US patents to his name and over 140 integrated circuits under his belt. He passed away on August 8th, 2012 at the age of 78, leaving the world a much buzzier and blinkier place.
He was also one of the first independent semiconductor designers, famed for hitting a home run with his first solo design–the 555 timer chip that has been incorporated into countless inexpensive electronic devices.
Incredibly, over one billion 555 timer chips are sold each year. It's a simple little 10 cent device that makes it possible to build devices that flash, buzz or turn on and off at variable intervals. Incredibly, he created the chip alone, spending a year designing it by hand as a freelancer.
In the early 1970s, Camenzind was working as a design engineer for Signetics. The company hit a rough patch and started losing money, and he responded to the downturn by taking a leave of absence to write a book. While away, he decided that he didn't want to return as an employee, and proposed the 555 timer chip as a freelance project.
Because of the downturn, the company had equipment to spare which they loaned him, and in the summer of 1970 they contracted him for a year at $1200 per month (about 2/3 of his former salary). It was an unusual arrangement in those days and a huge gamble for Camenzind, who had a wife and kids to feed.
However, he had a really clever idea. His previous work involved phase locked loops (PLLs)- circuits used to lock radio equipment to precise frequencies. A PLL requires a variable oscillator, which got Camenzind thinking–he knew there would be a market for an oscillator with an integrated timer that you could trigger and then let run for a set length of time. Such circuits existed, of course, but they required dozens of discrete components.
The idea was met with enthusiasm from Signetics' marketing manager Art Fury, who had a gut feeling that it would sell well. In those days, gut feelings were often good enough.
Figure 1. Switch Debouncing Circuit Diagram Using the 555 Timer
This is a switch debouncing circuit that employs a 555 timer IC. One problem with any pushbutton switch is the oscillation that occurs when it makes electrical contact to close the circuit. This can result in 'bounces' or undesired multiple pulses that can lead to errors in digital circuits.
The circuit above can be used to 'debounce' a pushbutton switch. It gets its initial trigger from the pushbutton switch and outputs a single clean pulse that the receiving circuit can use error-free. In this circuit, the 555 timer is essentially configured as a 555 monostable multivibrator.