controling a contactor with a secure digital timer ?

I am looking for an inexpensive way to have a user enter a security code and then enter a timer countdown value that will then activate a
relay or contactor. The access panel could not be tampered with or timer reset unless you knew the security code. I was thinking a keyed switch would be the easiest way but would not offer any duration, simple on or off. Any ideas on harware - I was thinking os some digital lcd hooked to a keypad of some sorts. But this is outside my range of expertise.
Thanks in advance
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RG wrote:

How about a cabinet with a lock? With a window in the door if need be?
There's probably a higher-tech solution available off the shelf, but sometimes the stone ax approach is still the best.
--

Tim Wescott
Wescott Design Services
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