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October 10, 2009

Countdown Timer using 555 Timer

10:43 PM  Sabarish  No comments

Countdown Timer:-In this Countdown Timer project, a 555 IC, a counter IC and a transistor switch to activate a relay either ON/OFF (mode selected by a jumper) as soon as the counting period is over. The circuit consists of an oscillator, a ripple and two switching transistors.Oscillator:-The 555 is configured in the standard astable oscillator circuit designed to give a square wave cycle at a period of around 1 cycle/sec. A potentiometer is included...
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Electronics is the study and use of electrical that operate by controlling the flow of electrons or other electrically charged particles in devices such as thermionic valves. and semiconductors. The pure study of such devices is considered as a branch of physics, while the design and construction electronic circuits to solve practical problems is called electronic engineering.

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