You may have experienced the dreaded Christmas lights nightmare. Where you have a string and half of it stays off. I'm talking about the strings of tiny bulbs in series that you can wrap around your tree, and plug directly into the 120V. (Talking about incandescents but I imagine it's the same idea with LEDs although much less likely to be needed of course. The following would not be needed or useful if the bulbs are in parallel.) You know there is a burned out bulb in there that interrupts the current. So you get a good bulb and start replacing each bulb in turn with the good one until you get the string back on. Great. However, that could take 30 mins if you're not lucky. And the little buggers are fragile and the wires tiny, and they break or get bent the wrong way, etc. And the bulbs may be hard to remove and replace. And if you are really unlucky, there may be 2 bulbs burned out or unseated and then you'll never find them that way...
Well, life is too short, there is a much easier to do this. Although you need one tool, but then you may already have it. I did, and it never crossed my mind to use it until today. Yes, I'm an idiot, because in retrospect it's obvious.
You know these little no-contact current detectors that are used to find out which wires are hot in an outlet. Work off the electromagnetic field generated by the current in a wire. Cheap. Lights up when there is a current nearby. They are very useful for general electrical work. Yup, that's right, you follow the hot wire (or check the bulbs directly) along the string and then at some point no more current seen. That's where the bad bulb is. No more unseating the ugly little bastids one at a time. I literally found out some bad bulbs in mere seconds that way today. There is a trick to it, though, you do have to be careful about your detector picking up the current only from one wire if there are 2 in parallel close to each other, but I found that if I separated the wires and shielded the wire with a finger I was then able to differentiate the wires well enough with the detector.
Happy Holidays!
Well, life is too short, there is a much easier to do this. Although you need one tool, but then you may already have it. I did, and it never crossed my mind to use it until today. Yes, I'm an idiot, because in retrospect it's obvious.
You know these little no-contact current detectors that are used to find out which wires are hot in an outlet. Work off the electromagnetic field generated by the current in a wire. Cheap. Lights up when there is a current nearby. They are very useful for general electrical work. Yup, that's right, you follow the hot wire (or check the bulbs directly) along the string and then at some point no more current seen. That's where the bad bulb is. No more unseating the ugly little bastids one at a time. I literally found out some bad bulbs in mere seconds that way today. There is a trick to it, though, you do have to be careful about your detector picking up the current only from one wire if there are 2 in parallel close to each other, but I found that if I separated the wires and shielded the wire with a finger I was then able to differentiate the wires well enough with the detector.
Happy Holidays!
