I like to ride my bike to work. It is great exercise and we have limited parking but with it getting darker earlier and my hours running late into the evening, I worry about motorists being to able to see me. I used an Instructable as a springboard and made some adjustments.

What it does

A roller is connected to the wheel of my bike which turns a stepper motor, sending a current to an old cell phone charger which then powers EL wire.

How I built it

First I had to determine what wires coming out of the stepper motor were live and common. Then I had to break a few old cell phone chargers. The third try was a charm. I was able to identify the transformer and connect the stepper motor wires. Then things got a little weird. Rather than remove the remainder of the charger, convert the current and risk blowing out the EL wire, we decided to keep the charger and send the current on through to the EL wire pocket inverter. I was able to strip the charger cord and attach it to the positive and negative of the pocket inverter with alligator clips. We then attached the stepper motor to an electric drill and tested it. The EL wire lit up but not consistently. We were able to trouble shoot the button feature on the pocket inverter and get the wire to blink consistently. Then I had to determine how to attach everything to my bike, 3D design and print a roller, and solder all of the alligator clip connections. Determining how to attach everything took a lot of trial and error and zip ties. I had to get the angle of roller to be compatible with my tire and keep the rest of the device from interfering. Then I began soldering the components together.

Challenges I ran into

  1. First, we were able to get the EL wire to light up but not consistently. Through trial and error, we were able to determine that the issue was the button on the pocket inverter. We had to solder a wire to keep the button continuously open.

  2. Once everything was working with alligator clips holding it together, I soldered everything. Then it stopped working. Using the drill and the mulitmeter, I was able to determine that issue was in the connection between phone charger cord and the pocket inverter but have not had time to successfully trouble shoot.

Accomplishments that I'm proud of

This entire project was out of my comfort zone and daunting. I am very proud to have gotten the current to work and gotten the roller to work with my bike wheel. I learned quite a bit about tools and electrical current. I'm proud of coming so close to making something practical and useful with parts that were around. I will continue to make this work.

What I learned

What a step motor is How to use a multimeter What a transformer looks like The basic concept of a transformer The basic concepts of AC and DC currents

What's next for Pedal Powered Bike Light

I need to continue working with the pocket inverter. Using the multimeter, I was able to measure current up to that connection. The EL wire is still working with a regular pocket inverter so the fault is somewhere in soldering the phone charger cord to the pocket inverter. Eventually, I would like to build a weather-proof housing unit and possibly condense some of the parts.

Built With

  • el-wire
  • old-cell-phone-charger
  • stepper-motor
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