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SMD LEDS safe on power supply? Answered

Hi,

I've taken two sets of 30 SMD Leds which were each powered by 3 AA batteries, and one set of 12 smd leds which was powered by usb.

I have chopped the power supply cords off, and connected all 3 sets to one mains phone charger plug transformer thingy, rated at 5v 2000mA

I think the current draw is around 1750mA so this should be safe.

However, can someone tell me for sure?

The charger gets warm, but has been runnning well for a couple of hours and the leds are nice and bright.

This should save me a fortune on batteries.




Tags:ledsmd

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-max-
-max-

5 years ago

3 AAA batteries will give you nominally 4.5V, but brand new fresh AAA's might give you up to 1.8V/cell, which would be 5.4V, and alkaline cells are usually considered dead by 0.9V/cell, or 2.7V. I think a 5V charger would work just fine, although you are cutting it close to the maximum current.

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-max-
-max-

Answer 5 years ago

Also, the LED strips probably already have small balancing resistors, so I don't think you will have to worry about that.

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ferrismrk
ferrismrk

5 years ago

No, I hadn't thought about that, I thought that they would just draw the current that they need. Not sure what to do now...

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Downunder35m
Downunder35m

Answer 5 years ago

Either get the right power supply or the right resistors for the LED's.
There are online calculators for the job ;)

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Downunder35m
Downunder35m

5 years ago

Might save you on batteries but did you account for a suitable current limiting resistor or LED driver?
With too much going in into the LED's in terms of amps and volts they won't last long.