Escape timer

407

07:53:03

Just push the switch and the timer will start. When timer finishes, the LED glows.
Change the timer value by changing Resistance R

Timer value=R*1.1*(10^-3)  seconds

Here timer value (20sec) is nothing but escape time.
This type of timer is used in bomb circuits, where planter triggers the circuit and starts to run. He has just 20sec to flee away. This time is called escape time. 

published 10 years ago

hurz

10 years ago

Why not put LED to + and remove extra NOT gate?

yashgumaste

10 years ago

I want to keep led off when timer countdown is running.

hurz

10 years ago

555 can sink and source current. Change your LED from source to sink and it would make the extra gate obsolete!

yashgumaste

10 years ago

Ok, I got it. Thank you. I got my concept cleared.

gopalbiswas

10 years ago

Y7y7

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