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
e-log of my experiments and experience in electronics- sathik ali