Checking voltage on LED power supply ?
Not RV related per se, but figured someone here would know. I recently purchased a set of LED lights to put some path lights to avoid tripping. Hooked up the lights and everything works fine. Ne...
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JoeH wrote:Gdetrailer wrote:JoeH wrote:Tom_M wrote:
Switch your meter to AC and check. Most likely one supply is AC and the other is DC.
Nope-- meter stays on "0" regardless of being on AC or DC.... but the LED lights out in the yard work. Strange
Post a pix of the power supply with the model number..
I suspect it is a high frequency switching supply and has no or little filtering on the output.. Most meters will not read at all or properly 15Khz-30khz frequencies which most switching supplies operate at which could explain why you can't get a reading but the lights work.
Quit raining and I went out to get a pic-- it is AC output but no reading on meter.
Coming up blanks on the brand and model numbers but with the pix, it is most definitely 12V AC output.
Doesn't look very big so I suspect it is a switching power supply and the output is at the switching frequency which may be the reason a meter doesn't read it.. Old school low voltage 60hz transformer systems were a fairly good sized box and heavy for the size.
If you had an analog meter it may show some voltage or if you had a oscilloscope you would be able to see the high frequency waveform..
LEDs are nothing more than a diode that happens to make light when a forward voltage is present, since AC alternates, the diode conducts 1/2 of the waveform making a LED workable on DC or AC..
However, some LEDs have a built in switching regulator that controls the voltage and current going through the LED.. This type of LED may or may not work every time with a high frequency AC power source.
In your case, everything has lined up and your additional LEDs are working fine with the yard light power supply you have.
