Power switch with regulator

Discussion in 'General Electronics Chat' started by imbellan, Jul 18, 2015.

  1. imbellan

    Thread Starter New Member

    Jul 18, 2015
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    I want to drive 24V, 5.75A in a circuit of LEDs.

    Because I cannot find the specific LED driver, I have to regulate it myself, but i am still a newbie.

    If I buy a power switch like this and I add this PWM to regulate the current, will I be able to have the 24V/5.75A?

    My understanding is that I can regulate the voltage on the power switch and the current with a PWM attached to it. So if I am not wrong the system would be something like:

    110V (home outlet) -> power switch 24V/7.3A -> PWM 24V/5.75A -> Load (LED).

    Is this correct?
     
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Wrong kind of PWM. That module has no feedback loop to make current constant; rather, it is configured to use PWM to create an adjustable voltage. This is not what you need to drive high-power LEDs. Get a proper constant-current LED driver power-supply designed expressly for that purpose.
     
  3. imbellan

    Thread Starter New Member

    Jul 18, 2015
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    Can't afford $70 (or more).

    What PWM/Current regulator (sorry don't know the proper name) should I get to regulate the current?

    Let's assume I can split the original LED strip in 8 parallel strips (0.7A x 8 = 5.6A): can I connect the power switch (48V/7.3A) to 8 parallel driver LDD-700h (2V-52V / 0.7A) like this ? http://www.meanwell.com/webapp/product/search.aspx?prod=LDD-H
     
    Last edited: Jul 18, 2015
  4. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Meanwell link doesn't work
     
  5. imbellan

    Thread Starter New Member

    Jul 18, 2015
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  6. imbellan

    Thread Starter New Member

    Jul 18, 2015
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    Anybody willing to help me with this question?
     
  7. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    I dont understand. You are buying a constant-voltage power-supply to make 24Vdc from line voltage, and then trying to come-up with a constant-current LED driver. Why not just get a line powered LED driver in the first place?
     
  8. imbellan

    Thread Starter New Member

    Jul 18, 2015
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    Because i need to power up different power strips, each at 24V but each requiring about 0.72A. Because I cannot afford to buy a led driver for each strip, my goal was to get a power supply that provides enough energy for the whole system. In other words, from one AC-DC power supply (110V -> 24V/7.3A) I want to draw 24v/0.72A per each strip (8 set in parallel).

    If I want to buy one single LED driver I am going to spend about $70-$80 plus shipping and taxes, and still not able to dim the lights independently from one another, nor I can add if I need, for example 3 more strips .

    If I buy a power switch, from which 8 different Meanwell LDD drivers can be connected in parallel, I will spend ~$22-$27 for the power supply, and about ~$35 - $40 for the the drivers, however, I can dim them independently and I can add (or remove) as needed other LEDs.

    This is why I want to find a way to regulate the current from the power switch.
     
  9. ian field

    Distinguished Member

    Oct 27, 2012
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    As someone else pointed out; a typical PWM regulates voltage not current.

    But if it gives you about 12V or so, that's a safe voltage to work with, and there's plenty of schematics online for simple linear 1 or 2 transistor current limit circuits.
     
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