Hello everyone,

I am working on a school project and got stuck on a circuit. I would like to make a circuit that when I press a button a light turns on and stays on for around 10/20 seconds. How can i do that? I found out that I could use an analog delay using resistors and capacitors or an ic like a 555 timer. What would be the best solution. The time does not have to be very exact just around 10/20 sec.

Thanks a lot

 

"Best" is in the eyes of the beholder. Only you can define what you mean by best. Lowest cost? Lowest number of components? Lightest weight, smallest footprint, on and on.

Either solution will work. Learning to use an RC timer has value, but the 555 IC is incredibly useful also and learning to use it is worth the effort.

 

These might be helpful. I was writing a blog and these are part of the subject matter.

 

http://www.google.co.uk/imgres?imgu...S_UPvsGqKw0AWSj4H4Aw&ved=0CDQQ9QEwAA&dur=4924


For approx 10 seconds make R1 100K and C1 100uF, for 15 seconds make R1 150K, 20 secs 200k

 

Thanks for all the reactions.

I think dodgydave's idea is exactly what i'm looking for. Thanks a lot. I'm going to the local electronics store tomorrow to get all the parts.

Hope seeing you on the forum!