Door bell timer using 555 IC?

[Keithstv]

Marks suggestions are good ones. If the transformer is 8V then the 12V zener could be replaced by a 9.1V one with no ill effect. It's always worth adding the extra pads for components you might need on a pcb and not fitting them much easier than not adding the pads and needing them later. Our PCBs at work usually have provision for extra components which we think may be needed.

Keith