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PSU Advice

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  • PSU Advice

    Hi guys. I have a problem I was hoping you can help me with

    I have built some tail lights for my car using 960 RED 5mm 6000mcd LED's per side (so a total of 1920) which all need to run at the same time for use as a taillight (with a lower output) and then full power for brake lights.

    The problem I have is that I have installed the LED's on Strip board (long boring job) and now having problems finding a way of powering them. The use of a resistor is not great as (1) the amount of LED's running on one resistor drops the light output too low and (2) the resistor gets damn hot very quickly.

    I would like to find a safe way of dropping the 12v-13.8v of the car battery down to a suitable high powered but 3.8-5v power for the LED's to run. I can use relays to switch them (no problems there) but need advice on a PSU for the lights. I was wondering if the 12v/5v PC power supplies that you guys use in your cars would do the job.

    Any ideas would be greatly appreciated.

    I currently have a fag lighter to 18v adapter running my laptop CarPC at the moment, which works great - but wondering if just another one of these will do - but have no idea of the power rating I will need as LED's are very low consumption by 1920 of them add up a bit! The funny thing - I can run all 1920 off two AA batteries fine!!!! And they run for days!

    Mick . . .

  • #2
    In a moment of clarity I just thought that I don't need a PSU, I just need a high power resistor of the right value.

    What "ohms" resistor will I need and where do I get such a thing in the UK?

    Mick . . .