LED torchlight are pretty common these days, but if you happen to have an incandescent filament light bulb based on 100 years old technology, here's your chance to have it updated with LED that last 8000 years! (if incandescent has a human lifespan)
What this instructable does:
Take a regular PR 2 bulb with a P13.5s base (i.e. those most commonly in torchlight), reuse the base and insert 3 x 5mm diameter white LEDs. See image of end result below.
The shortcut to this project is to go into a shop and buy one of these. But hey, what's the fun in that when you can make your own!
Step 1: Removing the Glass Bulb
This task is pretty hazardous, so be very careful, tiny shards of broken glass cut easily and are painful to remove (from my own encounter with a broken bottle), I suggest covering the bulb with a kitchen towel and gently grip with a plier, twist and nudge it out.
The glass bulb is fused to the metal base with a clay-like cement, and should crumble easily. Once the bulb is removed, use a mini screwdriver scrape the metal base clean. The internal surface wall of the base has to be electrically conductive.
What's left is seen in the image below.