LED switch.

joe155 · Post by **joe155** » Sun Jul 17, 2011 2:34 am

Hi, everyone, I am going to ask a silly question I know someone can help me, I suppose I am being a little dislexic tonight, but I am trying to hook up a toggle switch just to simply turn on 2 3mm LEDs I am using a 9 volt batt. for the job, it funtions well as it should when I turn it on, but when I turn it off the battery gets real HOT!!! I had used used the LED array Wizard to help me with the correct resistor to use, and that seemed to work well, but I just can't figure out what else I can do to stop this battery from heating so much,.. just 2 little LEDs are kicken my butt, its getting down right embarassing....hopfully someone can help... I woud apprciate all the help I can get..

tetsujin · Post by **tetsujin** » Sun Jul 17, 2011 2:58 am

Maybe instead of gating the current through the LED with the switch, you hooked it up so that it short-circuits the battery instead? Don't do that.

paraclete1 · Post by **paraclete1** » Sun Jul 17, 2011 3:25 am

Is the battery getting hot while the LEDs are lit?

If you have a multimeter, check for a short in the switch when its in the off position.

If the battery is only getting hot when the switch is off, it sounds like a dead short is happening in the switchs off position. I learned about dead shorts when I was carrying a 9v battery in my pocket and I put my dog tags in the same pocket. The chain laid across the terminals and my leg suddenly started getting hot to the point it almost blistered. If there isn't a load, the battery just burns up when the circuit is completed between terminals.

robiwon · Post by **robiwon** » Sun Jul 17, 2011 7:35 am

What wires do you have attached to your switch? Between the battery and LEDs you should have a black wire from the battery going to the switch, and then another black wire going from the switch to the LEDs.

joe155 · Post by **joe155** » Sun Jul 17, 2011 6:33 pm

OK!! I got it to work correctly, battery normal temp, LEDs @ full brightness, all works well, I want to thank every one that replied to my question, Thanks everyone!!

the problem was I did need to run another black wire from the LED to the switch, and that was the cure,..I have to thank robiwon for that....Thanks again.

paraclete1 · Post by **paraclete1** » Sun Jul 17, 2011 6:53 pm

Good Job!

robiwon · Post by **robiwon** » Mon Jul 18, 2011 4:00 am

Your welcome!