I have some short 6v led light strings that I would like to use on my Christmas layout. I would like to power them from a power supply instead of batteries. When I hook them up to the 6vdc power supply they burn up immediately.
Why? Excessive current from the power supply? Looking for a solution.
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Yes, excessive current. You need a 150 -100 Ohm resistor in series.
Just like how MTH powers similar LED strings. Nothing more than a rectifier, bulk capacitor, 6V regulator, and a large 1 Watt 100-150 Ohm resistor (depending on how long the string is) in series to the output. Agree with John, start with 150 Ohm first and see how bright the LEDs are.
You need a current limiting resistor in series with them. I'd start at 150 ohms and see how that works.
The battery LED lights are usually 3 (2 AA batteries) or 4.5 (3 AA batteries) volts.
The PS in your pic has a pot on it, try turning the voltage as low as it will go and then bring it up to the brightness you like. Remote possibility the pot sets the PS trip point, but as soon as you turn it, it should change the voltage if it is actually a volt control. That is a 10 turn pot, so it may take a turn or two.
I had some 125 ohm resistors on hand. Dropped the voltage to 5 volts as that is what is powering the LEDs in the houses.
Works great. Thanks for the quick replies. Another problems solved.
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