I didn’t really think fixing the Christmas Lights would be so easy:
I could never guess that zapping a Christmas light string could fix it. Like I mentioned in my video, my intention far zapping the light string was to detect the electric arc over the air gap of the blown light and easily pinpoint the broken light. But this ended up shorting the broken light and fixing the string.
This method could still be useful to detect arc on other kind of light strings that don’t have the luxury of getting shorted when zapped.
To create the high voltage spark, that can be over 10,000 volts, I used a piezo sparker commonly found in many different lighters, from kitchen to BBQ lighters.
Piezo Crystal is a material that can generate electricity and is use in many different applications in electronics. When the crystal is stressed, it generated voltage. The harder it is stressed, the higher voltage it generates. To create a spark, the sparkers hammer the crystal hard. This generates a huge voltage over 10,000 volt that can arc over air. Although it is a very high voltage event, it is extremely short and low power and doesn’t have a damaging effect on body, although it will make you jump.
When you zap a light string at its power plug, the energy travels over the wires and jump over broken lights and its energy is high enough to create a short bridge across the bulb.
So my lucky adventure fixed my light strings, although temporarily. The lights have a limited life span that gets even shorted being exposed to harsher environment, one of them being the higher supply voltage.
All the string lights are in series, hence all turning off when one goes. And so the AC voltage from the city gets almost equally divided over them. Now if we fix the string by shorting one light, the voltage is divided over fewer working lights which means a higher voltage across them. This reduces the life span of the lights. The more shorted bulbs, the worse the issue becomes. So it is better to replace the blown and shorted lights to avoid over voltage over the remaining bulbs. But at least now when you turn the string on, you see dead bulbs being off very easy and you can replace them
It is quite a strange fix. Apparently there is a bridge holding the wires in the light bulb that breaks short when exposed to high voltage arcs. When I did some more investigation after my lucky find, I realized that some other guy has actually made a product for this which is pretty good, although a simple sparker from a cheap lighter also has the same effect. Below is the video of the product, which can be more effective than a single sparker, but I think few people know about it: