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I have 4 led strips of 12 V, I want to connect them to a 48 V PSU, is the schematic bellow correct? Can I connect them in series?

enter image description here

Or do I have to connect them using a step down buck to 12 V?

Thanks.

Transistor
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superbem
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    If the load (current) for each string is identical, then yes. If one diode goes to open circuit, the other on that string will receive more current, causing shorter lifetime, more diodes fail and so on until everything is burned out. – winny Jan 11 '22 at 14:43
  • @winny I dont quite understand, how can I guarantee the load current identical in that shematic? the psu have 280a. Sorry I'm quite newbie in eletronics. – superbem Jan 11 '22 at 15:10
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    A ~13.5kW PSU? Unlikely... – Unimportant Jan 11 '22 at 15:37
  • @Unimportant it's a bank of batteries. – superbem Jan 11 '22 at 16:36
  • Then it’s not a PSU and your question does not reflect your actual situation. Get yourself a 48->12 V converter and save yourself the potential trouble with series connected loads. – winny Jan 11 '22 at 19:44
  • @winny How does not reflect the situation? Is there a trouble having much more current avaiable? – superbem Jan 11 '22 at 21:09
  • A battery bank is not a PSU with fixed DC output voltage. What’s the range from minimum to maximum battery voltage? – winny Jan 11 '22 at 21:17
  • @winny I dont know, its 16 of these https://www.alibaba.com/product-detail//4pcs-Lifepo4-3-2v-280Ah-Lithium_1600218570278.html – superbem Jan 11 '22 at 21:36
  • I’m afraid you are in over your head. Those batteries will push significant current if there is any problems, for example LEDs burning out. Again, make sure to use fuses for any load and get yourself a 48->12 V buck converter. – winny Jan 11 '22 at 22:23

2 Answers2

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As @winny's comment says, if each 12 V strip is identical, or draws the same current when supplied with 12 V, then you can connect them in series as shown.

If something goes wrong in one of the strips, for example if the strip contains individual LEDs in parallel and one of those fails open-circuit, then the strips will no longer be identical and the strip with the failed LED will have a greater share of the 48 V across it, which could lead to further failures. Also, even without a failure, any variation between the strips could lead to unequal distribution of the voltage across them and therefore unequal brightness. It would be more reliable to convert the 48 V supply to 12 V and wire the strips in parallel.

nekomatic
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48V strips would make a lot more sense than trying to put 4 12V strips together.

You can what you are proposing, but once diodes start failing the strip is likely to rapidly burn out, so be absolutely sure to use a fuse.

user1850479
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