I'm a mechanical engineer working on designing a simple time delay circuit for a DC motor. I took a stab a designing the circuit and the image is attached. I'd like it to work as follows: When the switch is closed, a small amount of current goes through to the timer. After the time is up, a standard 4 post relay is activated and the motor turns on for some time - 5 seconds or so. After that time the switch opens and the timer resets. The circuit is to launch a projectile which will depress the switch. When it launches, it will open the switch. The timer I plan to use is here: http://ics-timers.com/pdfile/interval.pdf

I have a couple of questions: Most important - will this work as I described? And the motor lists a stall amperage. Should there be enough power for the stall, or just enough to operator normally? Thanks for any help and suggestions.

 

1) wrong timer. This one starts "on" and quits later.
2) The bosses at this site don't like projectile guns. This thread will die a quick death.
3) All motors draw stall rated current when starting from zero. Just, some of them start so quickly that you can't measure it with a common meter. Be prepared to deliver stall rated current.

Good bye.

 

The circuit is to launch a projectile which will depress the switch. When it launches, it will open the switch. The timer I plan to use is here: http://ics-timers.com/pdfile/interval.pdf

Sounds like a Rube Goldberg, which are always fun. Problem is.. this statement seems contradictory, unless it's a normally closed switch.