Fixing an Indian LED & neon light

I thought it was about time I repaired an interesting light that a friend brought back from a visit to India for me. The Indian religious celebrations tend to involve a lot of exotic lights, and this one combines LEDs and a neon flicker flame globe.

I was hoping the fault was just going to be a fried resistor, and while the light did contain two very fried resistors, it turned out that the problem was actually in the neon globe itself.

So I took some measurements and made an openscad script to create a new insert that takes an E10 holder for a standard Christmas mini flicker flame lamp. Openscad is perfect for simple shapes like this with just four cylinders. The main body and its lip, then deducting the lamp base shroud and hole for the lamp holder.

I made the insert in PLA since it was in the printer already, and to keep the lamp base temperature down I added a series capacitor to reduce the dissipation of the resistor in the neon lamp's base.
It would probably be better to use a higher temperature plastic for the insert.

The end result looks good, and has the added advantage of being able to change the neon globe or even replace it with an LED one if desired. You could also modify the insert to add more LEDs in series with the existing ones. If using a lot you may have to upgrade the electrolytic capacitor's voltage rating to suit.

The use of a 50V capacitor in the LED circuit means that when an LED goes open circuit the voltage across the capacitor may increase above its rating. Because the supply is current limited that will tend to result in a controlled separation of the capacitors base and tube due to slow internal pressure build up.

Here's the openscad script I wrote to make the new insert.

//Indian lamp insert
$fn=100; //(cylinder facets)
difference(){
union(){
//flange
cylinder(h=1,d=28);
//insert
cylinder(h=3,d=24);
//main body
cylinder(h=20,d=18.4);
}
//safety rim
translate([0,0,10])
cylinder(h=11,d=16);
//lamp holder hole
translate([0,0,-1])
cylinder(h=25,d=10);
}


If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:- http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's algorithm quirks, allowing it to be a bit more dangerous and naughty.


#ElectronicsCreators