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0-99 seconds/minute 2 Digit Timer

I make this micro controller based timer as a part of shooter training Project.we can select and set time for a period of 0 t0 99 seconds or minutes. when the the timer is start.the 2 seven segment display start counting down .when it reach 0 an out put voltage activate buzzer or relay .so any electrical device can be switched on or off after a time delay


 

Microcontroller based design for greater accuracy and control
Power supply input 12 VDC 200 mA
Two 7  segments Display to display time
Single key start and dual key alarm time set function
Power and Relay-On LED indicator
Terminal connector for connecting power supply input and relay output to the PCB
Onboard regulator for regulated supply
Crystal resonator based design for better accuracy

there three buttons Up Down and set button


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