Housing for a switch-off timer

I have designed a kind of timer with which a 230V consumer can be disconnected from the power supply after an adjustable time.
The timer is switched on by means of a button that switches 230V to the power supply unit of the timer and to the 230V output. Behind the power supply is a circuit with an Atmel-CPU, which first switches on a relay connected in parallel to the push button and thus maintains the power supply for both consumers for e.g. 10 minutes.
Within these 10 minutes you have time to set an operating time for the consumer. After this time the relay is switched off and thus not only the consumer but also the time switch itself is completely disconnected from the power supply.

The project documentation can be found here (in German language)