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So I got these COB LEDs, and I want to wire them in parallel.

On one side, they have contacts labeled +/- and on the other there are two contacts labeled +/-B

enter image description here

How do I wire these? I am not quite sure what this -B is all about.

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  • \$\begingroup\$ Please provide a link to the manufacturer's datasheet for the the LEDs. \$\endgroup\$ Jan 29 at 13:37
  • \$\begingroup\$ The product speicifications are here: aliexpress.com/item/… (12010) No data sheet was provided \$\endgroup\$
    – sak
    Jan 29 at 13:48
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    \$\begingroup\$ No datasheet? No sale! \$\endgroup\$
    – Transistor
    Jan 29 at 13:59
  • \$\begingroup\$ Any idea what -B could mean in general? \$\endgroup\$
    – sak
    Jan 29 at 14:01
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    \$\begingroup\$ At that wattage and size, you will need to heat-sink them per the datash--- oh, never mind. \$\endgroup\$ Jan 30 at 1:20

3 Answers 3

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Use a multimeter continuity feature to confirm that the two + and - connections are just pass through and connected together.

These cobs are designed to run straight off 12V. So you just wire them in parallel. But keep in mind these are supposed 10W each, so they will heat up. And that they are unregulated so if the voltage goes up the current draw will increase. Use an appropriately sized resistor or add a voltage regulator to keep it at a reasonable voltage and current.

At 10W you probably want some heatsinking or fan as well.

enter image description here

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  • \$\begingroup\$ @j... if you want them to burn out in hours, sure connect them unregulated to a 14.6V active car power system. \$\endgroup\$
    – Passerby
    Jan 30 at 18:35
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Most probably these boards have solid wires going lengthwise just for connecting them in parallel, but mechanically in series. Such connection is also used in 12V LED stripes. You may check this easily with an ohmmeter. I don't know if they have same, matched current-voltage ratings (they give 12-14 V range in specs), this means that there are no ballast resistors inside, then adding a resistor in series with each module is advised. This will limit current through modules which have lower voltage and decrease heating and overpower.

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Without the datasheet one cannot say definitively.

In the tube days there were A, B and C supplies as a convention where "B" was the battery. You may find this in automotive work as well "B" for battery. Disclaimer> We are guessing without the datasheet https://antiqueradios.com/forums/viewtopic.php?f=3&t=318743

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    \$\begingroup\$ A and C were also frequently batteries. \$\endgroup\$
    – Hearth
    Jan 29 at 16:52

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