I need a electronic circuit designed

I am looking for an electronic timing circuit that will detect a phone line pick up (usually a ring voltage of 12v). Once a pick up is detected, the circuit will then start a timer that will trip a relay at the end of the timed period (which connects two points for a instant) then reset and wait again for the next phone line pick up. The timer on this board would be best if it was a variable timer that could be set anywhere from 0 to 30 minutes. (or it may just have presets like a 15 minute timer and a 30 minutes timer switch on it.)

My name is Paul and this is just a possible solution for what is being done manually at this time.

Skills: Circuit Design, Electrical Engineering, Electronics, Microcontroller, PCB Layout

Project ID: #30561248