how bout something like this?
Code:
________
C0------------->| |
C1------------->| |
C2------------->| |
C3------------->| |---------->12v
C4------------->| |
C5------------->| |
---------
^
|
|
12v
the 6 control lines (C0-C5) allow you to make settings from 0 - 63 seconds (standard binary values).
12V input is constantly applied, and this go's through the circuit, which allowes it to pass through to the output for as long as the control lines are set higher than 000000.
Once the timer reaches the value passed in through the control lines, the voltage is cut off to the output, and the control is reset to 000000.
The circuitis then redy to accept a new control value, and start the cycle all over again
Does this sound like it would work for your application? If so, we can start working on the circuitry to drive it.