Gadgetopia

You can make an electrical pulse with (almost) any shape that you want. EE101 generally starts with pulses and combinations thereof. That's one of the reasons that EE texts are inaccessible to people who actually know something about electronics. It is entirely possible to obtain an BSEE without knowing anything about electronics. But I digress.

Here, I'm guessing that the device generates a pulse with a relatively high voltage but a very limited current, sorta like a large battery in series with a high resistance. When the lamps are connected in series with the resistance, no current flows and all of the battery voltage appears across the filament of the open lamp. This high voltage (presumably) burns the resistive material off the bulb shunt and allows it to work. Once the shunt is activated and current starts to flow, most of the voltage appears across the high resistance and very little voltage appears across the shunt, thereby not burning it out. You can see a better way to do this with ICs, but the principle is the same.

If you want more info on the bulbs, page 3 of www.howstuffworks.com/christmas-lights.htm has a pretty good explanation.

hmm, sounds like a tool solely for the people who feel it necessary to cover their entire house in Christmas lights. The purpose of such an exercise eludes me.

btw, thanks for the explanation Brenda, very comprehensive.

sounds like a tool solely for the people who feel it necessary to cover their entire house in Christmas lights.

Not necessarily; I just hate throwing out a string of lights because of one stubborn bulb that doesn't do what it's supposed to do. I was talking with someone this morning about this thing, and she brought up the fact that although it may be cheaper to replace the lights than to buy & use a LightKeeper Pro to fix the string, what about a string of lights that's already strung up in your Christmas tree? If fixing a bad shunt keeps me from having to unstring and restring, I'm time ahead.

But there are some, like this guy, who definitely need one.

Thanks! It was fun to finally be able to contribute something to a site that I visit every day and that I enjoy a lot.

I have used this tool about 10 times this year and it worked 9 times. One application noone mentioend was on a pre-lit tree! Try popping 100 or so bulbs out from around the tree and next to the trunk. I used this to fixa bad shunt in 3 minutes and then replaced the bad bulb. It is also very handy if you lights up outside and a grid burns out (i.e. in net lights). You don't even have to take them down to fix them. I got mine after Christmas for $10. It is definitely worth even $20.

it quit working after the third string, what am I going to do about the other 40 or so I refuse to throw out.. It sucks.

It is amazing! After spending >$7 for icicle strings (and to do my roofline requires ~14 strings) a few years ago it has been extra frustrating each year to be throwing out icicle strings!

This has solved the problem and it works very well. I'm more of a 4 out of 5 times working situation but nonetheless it is an amazing tool and has easily saved me the $ of a new string and enormous frustration with bulb in bulb out stuff!

Great tool!

I love this tool. I can't tell you how many times I have used it and how many strands I have NOT thrown away because of this $20 tool. It is also convenient to test the fuses with it. I went back and bought extra tools to give away as Christmas gifts.

Are you kidding me, rather keep buying new strings at 3 bucks each. Oh yes , I would much rather keep driving to the store and wasting time and gas. Wow 20 dollars !! I bought this this thing and fixed some lawn fixtures that havent worked in years!!! It fixed every single string I tried it on. Only one note, I will say sometimes you have to try it in a couple diffrent sockets before some strings will light up. Great Great Great product.

PS. Most good light strings are about 8 bucks for just a 100 lights.