# What kind of LED driver do I need to replace this? Constant Current or Voltage



## Edwjmcgrath (Sep 28, 2019)

I’ve been debugging an expensive lighted mirror and I am pretty sure that the LED driver is failing. There are 6 LED bulbs in series and sometimes they will all work perfectly for a few minutes and then they will all turn off (or very dim). 

It should be obvious by looking at the driver specs what kind of driver this is, but to me it is ambiguous. Here’s what it says:

Hopestar Electronic Co LED DRIVER
Model: LED-24V350
Input: 120vac, 60Hz, 10w
Output:24Vdc,Max.330ma
12V...24Vdc, Constant 330ma

The second to the last line sounds like constant voltage while the last line sounds like constant current. 
Which is it? Anyone out there who can tell me what kind of driver I need to buy to replace this?

I have searched for this model for specs but it seems to be discontinued.


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## Edwjmcgrath (Oct 2, 2019)

Edwjmcgrath said:


> I’ve been debugging an expensive lighted mirror and I am pretty sure that the LED driver is failing. There are 6 LED bulbs in series and sometimes they will all work perfectly for a few minutes and then they will all turn off (or very dim).
> 
> It should be obvious by looking at the driver specs what kind of driver this is, but to me it is ambiguous. Here’s what it says:
> 
> ...


Since no one had a clue, I kept looking and although they are discontinued in the US, they still make the 220v 50Hz version. That was described as constant current so I bought a CC driver for $4 and that fixed it!


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## Dave_H (Oct 13, 2019)

Edwjmcgrath said:


> Since no one had a clue, I kept looking and although they are discontinued in the US, they still make the 220v 50Hz version. That was described as constant current so I bought a CC driver for $4 and that fixed it!



You've got it...

24vdc max. is just the voltage output limit to allow 330mA constant current. This drives each LED to about 1W. 
Too many LEDs in series (six is fine, seven probably the limit) would cause loss of regulation.

Dave


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## Mark R. (Oct 20, 2020)

Edwjmcgrath said:


> Since no one had a clue, I kept looking and although they are discontinued in the US, they still make the 220v 50Hz version. That was described as constant current so I bought a CC driver for $4 and that fixed it!



I also have an expensive lighted mirror (Kimball & Young) with the same driver. And the driver has failed completely. Can you point me to the replacement constant current LED driver you found? Thanks, Mark


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