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
