Newbie Help - 36vdc to 24vdc - RO/DI Booster & Switches Pump Setup

Discussion in 'General Electronics Chat' started by 1brent1, Nov 10, 2011.

  1. 1brent1

    Thread Starter New Member

    Nov 10, 2011
    I hope I'm at the right forum and apologize if I'm not. I want to see if something is possible and could really use a pro's help.

    This has to do with my RO/DI Water Unit that I use for my large Saltwater Fish/Reef tank. I'm running a 36VDC Booster Pump (Power Requirements: 36VDC, AMPS 0.22) that turns on and off automatically with Pressure switch that is all powered by 36VDC Power Adapter (Specs: Input AC 110V 60HZ, Output: DC 36V 1.5 Amps).
    Here's a photo of setup:

    "The red wire from Power Adapter goes directly to the Booster Pumps red wire. The black wire from the Power Adapter goes directly the Pressure Switch, then from their is goes to the black wire on the Booster Pump where it completes the circuit when the pressure switch is activated when it notices low water pressure"

    I recently purchased an Aquatec Auto Flush Timer, Model AFR608
    (Power Requirements: 24 VAC/24 VDC, 120 mA - flushing, 40mA – off cycle)
    What it does is automatically flushes my membrane every once in a while. I thought I could wire it in with my current booster pump setup but notice its powered by 24VAC/24VDC instead of 36VDC.

    Would it be possible to somehow wire it in with my 36VDC setup and Power Adapter with some type of Reducer or something, not sure what it would be called.

    Your Help & Knowledge is greatly appreciated!

    More info on the Aquatec Auto Flush Timer (model AFR608)
    Link 1 & Link 2 (PDF)

    Here's a photo I found of what the Aquatec Auto Flush Timer looks like wired on Aquatec's 24VAC system that it was designed for -
    Link to Image
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    Welcome to AAC.

    Ofcourse u can reduce the 36VDC to24VDC. You just need a stepdown regulator.

    Are you planning to buy one or make one.
  3. #12


    Nov 30, 2010
    It's called a voltage regulator. LM317 is a nice one. Only 1.44 watts of waste heat.
  4. 1brent1

    Thread Starter New Member

    Nov 10, 2011
    Good to hear.

    That PDF file with LM317's information is 21 pages, yikes.

    Is there something simple I can buy and wire?
    Buy this and put the one black wire from Auto Flush Valve here on voltage regulator,
    and then put the Second black wire from Auto Flush Valve here on voltage regulator.

    My power supply actually has a red and black wire coming out of it though, seen here, not two white wires like the above links/photos.

    The Power Supply still will need to power the Booster Pump & Pressure Switch at 36VDC.
  5. crutschow


    Mar 14, 2008
    The LM317 is really quite simple to use for fixed voltage output regulation. It just requires two resistors and two capacitors. See this for calculating the required resistor values.

    You should mount the LM317 on a small heatsink to dissipate the 1.5W maximum power dissipated.
  6. #12


    Nov 30, 2010
    If 5 parts is a bit much, you could try and buy a 512-LM7824CT chip for 66 cents plus shipping and do the job with 3 parts.

    Datasheet attached.