This simple LED light can replace the reflector hang tags that everyone loses from their timbuk 2 courier bag.

It uses a 555 timer to alternately flash each set of 9 LEDs, for 18 blinking LEDs of goodness.

Step 1: Parts

Parts:

4 AA Battery holder
Switch
PNP Transistor (3906)
NPN Transistor (2222)
555 Timer
150k resistor
4.7k resistor
1uF Capacitor
160 Capacitor
220 Capacitor
Breadboard
19 LEDs
Wire
2 x 3./4" Quick relase
12" of webbing
2 x molex KK connectors

Tools:

Soldering Iron
thread and needle
pliers
wire snips

Step 2: Cut Out the Straps

Cut your straps to the same length as the original reflector tags, which is about 5" and leave a small tail to put through the quick release.

Sew it together so it will nto come out of the quick release

Step 3: Build and Test Your Circuit

So I the circuit used is a 555 timer circuit, the one I like the most is on Bill Bowden's web site: http://ourworld.compuserve.com/homepages/Bill_Bowden/555.htm. Build it out on the breadboard and see how it works.

Step 4: Solder It Up.

Solder everything together.

Here I used two molex KK connectors, one for each set of LEDs.

Step 5: Time for the Flaps

So here I just poked the LEDs through the webbing, make sure all of your negatives are on one side.

Then cut 2 18" lengths of wire. Strip enough off of the end to cover all of the LED negative pins and then solder them each to the wire.

Do the same for the positive side.

Here solder on the female molex KK connector and the snap it on to your breadboard.

Do the same for each side.