Hi alic_t
Firstly let me put your mind at ease the door opener will be used to open/close the doors to my hen houses the idea is to save me having to open the door to let them out early in the morning and to close the door in the evening realy usefull if I am away from home in the evening.
The answer to your questions I do have a mains electronic timer 7 day 8 on off settings, the shortest timer segment is 1 minute as for any voltage on the button wires I have tested both wires with my tester set to DC v and the only figure I could read was on the red trace wire which read 00.4 these 2 wires are only bell wire and they go to the circuit board the terminals are marked 1 and 2 number 2 is red the red trace wire is attached. the answer to your last question, my idea was to plug into the timer a transformer something like an old phone charger I have lots of these typ of transformers ranging from 18v dc to 3v dc the timer would turn on the transfotmer and the dc volt would operate a switch which would connect the 2 operating wires and start the motor, the timer would turn off when the power stops the switch resets until the timer turns on again, the time the motor runs is adjustable in the motor housing. The only thing I am unsure about is if the wires are kept connected for the 1 minute the timer takes to switch off, if I used a switch which reset after 2 or 3 second would it be re trigered because the power would still be present. I hopes helps you
Gosh I am sorry this post is so long try not to lose interest befor you Finnish reading.
Les