Variable time, digital countdown timer with relay output

[DGDasher]

Hi all,

I am looking for a schematic (I'm sure there is bound to be one there somewhere so I dont have to re-invent the wheel) to allow me to have an output relay controlled by a countdown timer. Times of 1second increments varying between 2 and 200 seconds.

Ideally 4 buttons. 2 for Up and down of the time, 1 for reset and 1 for start

Digital display to show the selected time.

Has anyone stumbled on such a beast?

 

[BrownOut]

Start with the 74HC161, 'bout 50 cests a throw at Digikey