I wired a large building with LEDs It worked fine on my bench with my 12V power supply. I took it to the club and wired it to their 12 power supply and it blew some but not all the bulbs. Theye were not the flash burn out that I get when I forget the resister. It took a while. I don’t even know what questions to aks. Anyone up to consulting with me here?
I suspect the simplest cause - the club power supply was significantly more than 12 volts.
What value resistors did you use? If the LEDs are rated for 20-25ma, you want to design to something well under that - half would be a good point, so about a 1K resistor. They will be plenty bright for building lights. And that leaves plent of head room so that even if connected to a power supply putting out 24 volts, they wouldn’t blow.
Also, did you use 1 resistor per LED, or try wiring some in parallel with a single resistor? Parallel LEDs can lead to a cascade effect since the current changes when one blow out - the rest will all be over current and you get a chain reaction.
Series resistors are OK, if they are all the same. For 12V you can get away with 3 in series, you need to calculate the resistor based on the LED voltage, adding up all 3.
Best is just 1 resistor per LED, then you know it’s right. And since bulk resistors are less than a penny each, it’s not expensive.
–Randy
Try this array wizard. It is for dummies like me.
I have used 1k, 1/4 watt resistors for some years. Allows about 9ma current with plenty of brightness.
Below is a link you might like.
http://www.members.optusnet.com.au/nswmn1/Lights_in_DCC.htm
You can also Google led’s series parallel and get lots of link.
I know a few here don’t like using google but it has never failed me in many years.
Rich
Were your LEDs wired in series? :ION tried that, all have been removed and replaced with Parallel wiring.
ROAR