For our other free eBooks, Go to: 1 - 100 Transistor Circuits Go to: 101 - 200 Transistor Circuits Go to: 100 IC Circuits
For more data on the 555, see these pages: 555-Page 1 555-Page 2 555-Page 3 555-Test for CD users: 555-Page 1 555-Page 2 555-Page 3 555-Test
To learn about the development andhistory of the 555, go to these links: http://semiconductormuseum.com/Museum_Index.htm - a general discussion about the development of the transistor http://semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzind_Index.htm history of the 555 - Page1 http://www.semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzind_Page2.h tm - history of the 555 - Page2http://www.semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzind_Page3.h tm - history of the 555 - Page3 http://www.semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzind_Page4.h tm - history of the 555 - Page4 http://www.semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzind_Page5.h tm - history of the 555 - Page5http://www.semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzind_Page6.h tm - history of the 555 - Page6 http://www.semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzind_Page7.h
tm - history of the 555 - Page7 http://www.semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzind_Page8.h tm - history of the 555 - Page8 http://www.semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzind_Page9.h tm - history ofthe 555 - Page9 http://www.semiconductormuseum.com/Transistors/LectureHall/Camenzind/Camenzind_Page10. htm - history of the 555 - Page10
For a list of every electronic symbol, see: Circuit Symbols. For more articles and projects for the hobbyist: see TALKING ELECTRONICS WEBSITE 84 CIRCUITS as of 12-9-2010 plus Frequency Divider, Constant Current, 170v Power Supply, Audio Frequency Meter,Toggle, Reversing A Motor, Automatic Curtain Closer, Stepper Motor Controller, Animated Display Controller, 4 Alarm Sounds, Dice LED Effects, Headlight Selector 97 CIRCUITS as of 12-1-2011 plus 12v DC to 12v DC Battery Charger Water Level Detector
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This e-book covers the 555.
The 555 is everywhere and it is oneof the cheapest and most-rugged chips on the market. It comes as a TTL 555 and will operate from 4v to about 16-18v. It costs from 20 cents (eBay) to $1.20 depending on the quantity and distributor. The circuitry inside the chip takes about 10mA - even when the output is not driving a load. This means it is not suitable for battery operation if the chip is to be powered ALL THE TIME. The 555 isalso available as a CMOS chip (ICM7555 or ICL7555 or TLC555) and will operate from 2v to 18v and takes 60uA when the circuitry inside the chip is powered. The "7555" costs from 60 cents (eBay) to $2.00 We call the TTL version "555" and the CMOS version "7555." This is called ELECTRONICS JARGON. The 555 comes as a single timer in an 8-pin package or a dual timer (556) in a 14 pin package. The 7555comes as a single timer in an 8-pin package or a dual timer (7556) in a 14 pin package. The 555 and 7555 are called TIMERS or Timer Chips. They contain about 28 transistors and the only extra components you need are called TIMING COMPONENTS. This is an external resistor and capacitor. When a capacitor is connected to a voltage, it takes a
period of time to charge. If a resistor is placed inseries with the capacitor, the timing will increase. The chip detects the rising and falling voltage on the capacitor. When the voltage on the capacitor is 2/3 of the supply the output goes LOW and when the voltage falls to 1/3, the output goes HIGH. We can also do other things with the chip such as "freezing" or halting its operation, or allowing it to produce a single HIGH-LOW on the output pin....