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Prerequisite: For a home-decor project, we wish to work with different LED strips and even a larger LED chip as a central lighting source by attaching everything to a powerful, high quality 12v CC/CV DC PSU. (eg., Mean Well HLG series).

  • Each portion of LED strips, depending on chips / resistors, will draw different currents.

  • For the central lighting, we wish to use a CC / CV DC booster to drive a high-power LED.

Given that the total power consumption from all components is well below 90% of PSU capacity;

  • Would it be safe to connect all components in parallel and use the single PSU to power them?

Edit:
This question is not a duplicate on this site. It is irrelevant to, for example, the following:
Can I safely and efficiently connect batteries parallel to a DC source? or:
Choosing power supply, how to get the voltage and current ratings?

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Phil
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    shouldn't be a problem, just add appropriate fuses with maximum allowed currents. also make sure you're cables are rated for the currents you're drawing. – Flying Swissman Dec 01 '14 at 18:42
  • You should know that every computer in existence already does this with its PSU and its devices. – Dan D. Dec 01 '14 at 18:42
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    Can you give more information about the LED strips and the high-power LED chip? If they all work at 12V DC input and they have integrated constant-current sources, you should be good. If you are directly driving an LED or string of LEDs without resistors, which requires a constant current, you may be in trouble (especially with multiple different constant-current components on the bus). – Justin Dec 01 '14 at 18:50
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    @Justin he said he's limiting the current with resistors – Flying Swissman Dec 01 '14 at 18:53
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    @FlyingSwissman - It should be fine then. It's not clear in the question whether the high-power LED is current limited (well, I'm not really sure where the "CC / CV DC booster" fits in...) – Justin Dec 01 '14 at 18:58
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    @Justin oh sorry missed that. – Flying Swissman Dec 01 '14 at 19:05
  • possible duplicate of [Choosing power supply, how to get the voltage and current ratings?](http://electronics.stackexchange.com/questions/34745/choosing-power-supply-how-to-get-the-voltage-and-current-ratings) – Passerby Dec 01 '14 at 20:39
  • @Passerby did you actually read either question before suggesting a duplicate? They are irrelevant. – Phil Dec 02 '14 at 00:20
  • Yes Phil, I have. The answer and question is the same thing. And others agreed. – Passerby Dec 02 '14 at 00:45
  • Otherwise, explain how they aren't duplicates. – Passerby Dec 02 '14 at 01:04
  • I don't need to explain @Passerby. It simply isn't the same thing, it has nothing to do with it. But since people can be lazy enough not to read, I shall explain it for you: This question asks about safety of parallel wiring things WITH a DC booster on one of the connections!!!! So I suggest, you read again. This time to understand, not to cause disputes. Thanks. If you don't want to read, that's fine, I don't care. All you are doing is making it hard in future for those who are interested in using DC BOOSTERS safely with other components in parallel. Be proud. – Phil Dec 02 '14 at 10:12
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    -1 for the attitude. Are you asking if multiple things can be powered from the same supply? Do you see a 1MW power plant for every building with electrical service? – Matt Young Dec 02 '14 at 13:34
  • Is this a joke @MattYoung? Press -1 x100 with all your accounts if you like - all you are doing is damaging other people's chances to learn about this topic. It involves a DC BOOSTER attached to the circuit. Read the question first. It is not a duplicate by any means. Oh, here, on SE, we vote questions on their own merit BTW so **OTHERS** (an interesting concept) can benefit as well. Thinking about those *others* takes less ego and more selflessness though, doesn't it? Calling a Q "duplicate" without reading and downvoting as you like .. very mature. I will defend this for OTHERS' benefit. – Phil Dec 02 '14 at 14:18
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    I really fail to see what there is to learn here. If you're really asking if loads can be connected in parallel, that's a silly question that can be answered in a simple thought excercise. Your "DC BOOSTER" does not change physics. And seriously, if you want to be part of this community, lose the attitude, we don't want or need it. – Matt Young Dec 02 '14 at 14:26
  • You will continue to fail to see as long as you do not READ and try to understand. The question clearly asks IF IT IS SAFE to use a DC BOOSTER. I don't have an attitude, just allergic to selfishness and ego. You brought nothing to this thread but an empty argument. – Phil Dec 02 '14 at 16:24

1 Answers1

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Yes. The power supply will make 12 V as long as you don't exceed its current rating, which you say you know you won't exceed. Otherwise, 12 V is 12 V, regardless of how much current someone else is drawing from it.

A related issue you should think about carefully is voltage drop in the wires. The power supply will do a good job of making 12 V at it's output, but that's not the same as 12 V at the other end of a 18 guage wire across the room, especially when something else is also trying to draw power from the remote end of the wire.

Think of the wires as series resistors and plan out your system accordingly. The resistance of various sizes of copper wires is well documented out there. Remember that you have two wires, + and -, so the total series resistance seen at the end of a cable will be twice that of one wire.

You can trade off losses in the wire, voltage drop at the end of the wire, number of units fed from a single cable, and thickness of the conductors. There is no single magic answers. It is up to you to pick the best tradeoff, where "best" is measured by a weighting of factors that only you can decide.

Olin Lathrop
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  • Whoever downvoted this, please explain what you think is wrong, misleading, or badly written. I have re-read this and still think it is correct. Silent downvotes do the site a disservice since we have no way to know what to fix, or whether the misconception is on your end. – Olin Lathrop Dec 02 '14 at 14:54
  • +1 +4 years on to make up for stupid downvote. And +1 anyway :-) – Russell McMahon May 20 '19 at 11:16