DIY

CIRCUITS

MINI BIKE LIGHT

Make an easy LED headlight from a garden hose adapter. By Trevor Shannon

Photography by Trevor Shannon and Katie Dektar

I wanted to build a small, bright, and durable LED light for my bike, and I read online that plumbing parts work well as housings. So I made a 3-LED headlamp that’s enclosed by a ¾" hose faucet adapter and powered by an outboard battery pack.

1. Make the LED mount.

To hold the LEDs, I used some scrap translucent plastic. Using a drill press, I marked an outline on the plastic sheet by cutting partway through with a 1¼" hole saw. I drilled three 5mm holes inside it for the LEDs, then finished cutting out the disk with the hole saw.

Trim the edges of the disk until it fits snugly in the rubber side of the hose adapter, stretching the rubber a bit. I used a grinder, but you can also use a file or sandpaper (Figure A, following page).

MATERIALS AND TOOLS

White 5mm LEDs, 3.6V, 20mA ( 3) part #276-320 at RadioShack, or cheaper from mouser.com or other online suppliers

15Ω resistor I determined the resistor’s value using a formula described in instructables.com/ id/LEDs-for-Beginners.

3-AAA battery holder ( 1) with batteries ( 3)

Small SPST toggle switch I used a micro-mini toggle, RadioShack #275-624, for a second, more streamlined version of the light.

Insulated wire, electrical tape, and super glue ¾" garden hose faucet adapter clamp style

¼" hard translucent plastic small sheet or scrap 1¼" hose clamp and 1 extra clamp

Soldering materials

Drill press with 5mm bit and 1¼" hole saw Grinder, file, or sandpaper

Make: 129