DC Supply Loading

Discussion in 'The Projects Forum' started by CassieD, Jun 10, 2013.

  1. CassieD

    Thread Starter New Member

    Jun 19, 2012

    I'm trying to power a bunch of sensors with a DC supply. I'm trying to figure out if I will run into complications when I'm using the same DC Power Supply to power up to 100 sensors. The sensors need a supply voltage between 7-35V and a supply current of 15-30mA. I'm using an Extech 338213 power supply.

    Thank you in advance.
  2. Dr.killjoy

    Well-Known Member

    Apr 28, 2013
    Personal I was make a mutli rail setup for long term use and I think you would be pushing the power supply if you turn on the sensor all at once because your reaching max current and not including the surge current ...Also with a multi rail setup ,if something where to go wrong then you don't have to worry about destroying everything just everything on that rail...
  3. CassieD

    Thread Starter New Member

    Jun 19, 2012
    Thank you for your response. So your recommending with the multi rail setup that I have a different power supply per rail? Maybe have half of the 100 sensors to one dc supply and half to the other? I don't want anything getting destroyed.

    If I'm thinking about this correctly the max current of the supply is 3A and the sensors need 30mA max. So 3/.03 is 100 but it may be risky to use exactly 100 sensors...
  4. wayneh


    Sep 9, 2010
    Running any supply for extended periods at its rated current is not the greatest idea. If the designers were conservative in the rating, it will be OK but if they were a bit optimistic, shall we say, you're asking for trouble.

    I don't really see a huge problem powering multiple small devices from a single supply as long as the power-on startup current is not a problem and the supply can handle the continuous load. These are the same concerns with any supply and load. Multiple small devices are really no different than a single larger device.
  5. crutschow


    Mar 14, 2008
    If they don't already have it, you should add some decoupling capacitance at each sensor.