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DC - how many miliamps

  1. Jun 27, 2009 #1
    First off, I know very little.

    I want to install a cabinet in my garage. It runs on 120AC, and then provides me 16 DC outputs. As I understand it the total output is 10,000 ma. I have some DC powered items that require 500ma, and some that require 1,000ma. I'm only going to use 6 of these power output connections - total requirement is 4,000ma. I might add a couple other devices later.

    For now, I'm just trying to learn about this. I'm not going to put start this project until I fully understand what's happening.

    So, teach me something about the above.

    Another question: If I have a device that required 500ma, can I use a power supply that provides 1,000ma.

    Teach me something. I discovered PF today and I think I'm gonna love this place. Neat discussions.

  2. jcsd
  3. Jun 27, 2009 #2


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    The total current of the devices plugged into the supply must be less than the maximum capacity of the supply; it does not matter how many outputs you use, provided the above is true. A device will only draw what it requires; as long as the voltage is correct, the capacity of the supply is immaterial. If the supply is regulated, you need only be sure the rated output voltage matches the voltage requirement of the device under power. If the supply is unregulated, you need to be sure that the output voltage does not exceed the device's maximum at the load it will draw. As an example, if an unregulated supply is rated at 5 VDC @ 1000 mA the voltage at lower currents could be siignificantly higher, depending on various factors, something like 7 VDC @ 500 mA, perhaps.
  4. Jun 27, 2009 #3


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    Just so that we don't misunderstand you, could you add some more information:

    What is the "CABINET" you are going to build? Is it a power supply that converts 110 volts AC to lower DC voltages?

    WHICH DC voltages does it supply?

    What DC powered items do you intend to supply off this DC supply? eg "CD player", not "Sony gfd1234".
    Do you know what voltages and currents they need?
    Do you know which polarity the input voltage to these devices has to be? ie where does plus and minus go on the power inputs?

    If these voltages are different, can you be sure to use different plugs so that they don't get plugged into the wrong supplies?
  5. Jun 28, 2009 #4
    Current is like the amount of water that flows.

    Generally power supplies can only give you a certain amount of current. If you go over they start heating up too much and go up into flames.
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