More Hippies on your head!
- 5W 12V Halogen globe (sealed front): from
- Halogen globe holder: from Jaycar
- Switch: from Jaycar ~$1 each
- Cheap torch : $3.50
- Assorted odds and sods: from home $0
Of course, walking past or through electronics shops like Jaycar is a dangerous thing. Especially when you find 5w 12V halogen globes. These don't have the integrated reflector that the normal dichroic globes do, but the idea of a low powered light for use as a head lamp, or a commuting light, was just too cool to ignore...
The first thing required was a suitable reflector assembly. A visit to the $2 shop turned up a torch, with batteries, for only $3.50. Since I already had switches and a few globe holders at home, this was all I needed.
The first thing to do was pull out the reflector assembly and see if it was at all useful. This torch has an outer shell that screws onto the main body.Inside this shell is a front plate and the reflector assembly, which has a screw on bulb holder.
Pulling out the bulb holder and checking fits, it was fairly obvious that the halogen base would need to sit pretty much flush with the back of the reflector. The obvious thing to do was attach a screw thread to it, and the obvious screw thread was the one that came with the torch. A hacksaw was wielded, some small screws located, and an attempt was made to attach the remaining thread.
The biggest problem was that the chopped off thread had almost exactly the same diameter as the distance between the two holes in the halogen globe holder. After a couple of unsuccessful attempts to get a screw to bite into the remaining 2mm thickness of plastic, brute force was applied. Slight vice pressure "ovalised" the threaded ring of plastic, and the screws were inserted so they were aligned with the long axis. When the vice pressure was released the ring snapped back to a circular shape and was securely held. Except it also just snapped... Luckily it still screws into the reflector!
Now that the reflector assembly was together, the rest of the torch could be used. The first step was to make it a bit shorter, and the hacksaw was again wielded. If you're using a cheap torch be careful - the plastic can shatter quite violently.
Removing the original switch and internals was accomplished by melting them out with a soldering iron. The same technique was used to shape the original switch area to accept a spare switch I had lying around from previous projects. A conventional circuit was soldered together, and the light was almost complete.
But what about that big ugly hole in the end? No problem. Trim the base of the original torch as close as possible and drill a hole in it.Put a DC jack in it (I used an RCA plug scavenged from another light, but I like pretty sparks) and solder the wires to it. Now use the soldering iron to melt the base back onto the shortened torch - voila!
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