Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Powering Sprinkler Actuators

  1. Mar 15, 2010 #1
    I have several 9vdc powered items that are used for scaring deer out of my yard. The device is motion activated and opens a solenoid that allows a sprinkler head to send a 4 second burst out. These work well, but if the battery runs down, the deer win. I would like to use low voltage ac (as in yard landscape lighting) to power these units. I think those transformers operate at 12-14 vac and up to 300watts. Do not know that amperage requirement for my deer device but it can't be much.

    What I want to do is to "convert the devices" to run on 12 vac.

    I also have a similar device that runs on 2 D cell batteries (3vdc) and one that runs on a single 9vdc battery. Would like all to be powered by a single landscape lighting transformer.

    Can anyone help?
     
  2. jcsd
  3. Mar 15, 2010 #2
    Re: how to convert DC to AC??

    Thom,

    You might try part# MW117RA0903B01 from Mouser. It's 9 volts, regulated and can supply better than 1 amp. It's not intended for outdoor use, but would be okay for a garage or NEMA enclosure.
     
  4. Mar 15, 2010 #3

    turbo

    User Avatar
    Gold Member

    I have those 9v motion-activated sprinklers on each end of my vegetable garden. The batteries last for a whole growing season each year. You may have the sensitivity set too high, so you're getting a lot of false-positives. That will wear down the batteries and waste water, as well. Buy some decent alkaline batteries, and adjust the sensitivity of the sensors so that you don't get false-positives, and you should be OK.
     
  5. Mar 15, 2010 #4
    thanks for the replies. both of you. I find the units to be inconsistent when i adjust the sensitivity down. so i keep it up and the units activate many times each day. I do have the water source on a timer so that it only sprays at night time. but if i miss one night with a dead battery the deer could eat 20 indian hawthornes. I am mad and want to beat the little pests
     
  6. Mar 15, 2010 #5

    turbo

    User Avatar
    Gold Member

    You can save water with the timers, but you can't save batteries. The false-positives eat them up. I have to set my deer-chasers up as if they were a perimeter. I can't set them up in line-of-sight with the plants in my garden because wind moving the foliage can trip them easily. I have to treat them as if they are guardians for the approach-paths to my garden, and not to detect deer IN my garden. Deer are pretty smart and adaptable.

    When we first moved to this log house in the country, a doe with twin fawns used to park her babies on our front lawn every night. I'd find a large kidney-shaped depression in the lawn, and two tiny ones right next to it. They often used to sleep right next to the concrete front patio, about 5 feet from the house. Our garden that first year was very poor, so I didn't care all that much, but after I lost my job due to disability, I got really serious about growing and keeping as many vegetables as possible. Since installing the deer-chasers, no deer have been camping out on my lawn during the summers. I love them and want to protect the fawns from coyotes, but I really need to protect my garden.
     
  7. Mar 16, 2010 #6
    I am still in the process of deciding on best locations. I want to hard pipe the water so that unsightly hoses not laying around. Can you say what brand (Havahart or Contech Scarecrow) you have? I have two that put out a blast of ultra sound followed by 3 blasts from a party whistle. Those are inconsistent on the motion detecting. Have 2 others that put out a blast of ultra sound followed by 4 seconds of talk radio. They seem to be the most consistent. But all depend on batteries and even if I am not getting falsies I would like to run them off landscape lighting source.

    I understand a lot about electronics but am niether educated or experienced with making the conversion.
     
  8. Mar 16, 2010 #7

    turbo

    User Avatar
    Gold Member

    I have the Scarecrows. I put one on each end of my garden, aimed along the open space at the end perimeters. They reliably detect large animals and humans at a distance of at least 40 feet. The only noise that they make is the clacking of the lightweight plastic "flapper" that deflects the water from the sprinkler. I can see why you might be having battery issues, if your units make loud noises. All the scarecrows do is open a valve, and the water does the rest of the work.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook