need a countdown timer for a pump motor

Discussion in 'General Electronics Chat' started by Lyttleton, Feb 26, 2011.

  1. Lyttleton

    Thread Starter New Member

    Feb 26, 2011
    I have a 12vdc motor driving a pump that supplies pressurized water on an old trawler. The pump is switched on/off by a conventional pressure switch. At one time, there was a timer in the motor circuit that shut the pump down after 5 minutes of operation. That is, the timer shut the pump down regardless of the pressure in the system.

    The timer served two purposes. First, it provided protection against the possibility of running the pump dry; and second, it prevented excessively long showers. Unfortunately, it burned out after only 20/25 years of service and I am having difficulty finding a replacement.

    Note that the pump may draw as much as 10 amps on startup and that the timer needs to reset itself each time the pump is switched on. The accuracy of the timer is not critical and some kind of manual reset would be ideal.

    Any ideas where I can find an off-the-shelf replacement or the components needed to build one will be greatly appreciated.


  2. Kermit2

    AAC Fanatic!

    Feb 5, 2010
  3. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    Does it need a down- or up-counting display as well, or just a timer function?