LED dome light

I used to have a 24LED dome light installed in my car.

Except one day I decided 24 LEDs are not enough. And I want to try another colour.

Before I start:


Cutting the PCB to make it fit:




I modified every LED used so I can fit the most amount of LEDs on there:


Modified the dome light housing for more space:


All LEDs in place:


Quality soldering... or maybe not, but good enough.
Instead of having a set of LEDs in series with its own dropping resistor, then parallel connecting each set together, I decided to connect a group of LEDs in parallel, and each group will be connected in series, with only one dropping resistor.


I should have used a 82ohm resistor, but the closest The Source did not have it in a high enough wattage.
So I got a 100ohm instead.
It is rated for 1 watt.


After 30 minutes of trying, I still cannot get solder to stick to the electrical connection on the dome light.


So I just wrap it around, solder the wire to keep it wrapped, and used hot glue to hold it in place.



Everything in place.
You may notice that I did not leave any space between the LED and the PCB.
The light usually will not stay on for more than 20 seconds, so heat is not a huge concern for me.


And installed.


In the end, I managed to fit 66 LEDs in there.
Based on some online calculators, it will use about 3w of power.