Bug or Feature? DIY Bicycle Power Generation Using a LIN-only Alternator! Preparing for Power Outages

In this project, I took on the challenge of “Bicycle Power Generation with a LIN-only Alternator."

 

This project involves using an alternator with LIN communication as a generator and building a mechanism to actually generate electricity using a bicycle.
The content is designed to be enjoyable for those interested in the combination of DIY and technology.

 

目次

What are LIN Communication and Alternators anyway?

  • LIN Communication: A simple serial communication standard used between Electronic Control Units (ECUs) in vehicles. It is characterized by low cost and low power consumption.
  • Alternator: A generator installed in vehicles that has the role of converting engine rotation into electrical energy.

In a general alternator, the output voltage is adjusted according to the engine’s rotation, but types that allow control via LIN communication enable more detailed settings.

Materials Used

The materials used in this project are as follows:

  • LIN-compatible alternator (Used: Taken from a Mazda Carol DBA-HB36S that I impulse-bought 5 years ago)
  • Standard road bike
  • 12V-5Ah Sealed Lead-Acid Battery
  • Voltmeter, switches (for monitoring and controlling power generation)
  • Case created with a 3D printer
  • Copper-clad laminate board processed with a CNC machine

Work Procedure

  1. Checking the Alternator’s Operation

    The alternator used this time was a used unit, and the model number of the built-in regulator IC could not be identified even after disassembly. Therefore, for this test, I referred to the “standalone mode" described in the datasheet of a different regulator IC for LIN-compatible alternators, rather than the datasheet for this specific alternator.

    In standalone mode, LIN communication is not required, and the specification is to start generating power at a certain RPM or higher. However, during the operation check, no matter how much I spun the alternator, it only generated a few volts, which couldn’t be considered actual power generation. Normally, when installed in a vehicle, it is connected to a 12V battery. So, I tried spinning it while connected to a battery, but power generation still did not start.

    As a trial, I tried connecting the 12V battery while the alternator was spinning at about 2,000 RPM, and finally, power generation began. From this, I realized that a certain initial rotation speed is necessary for the alternator to start generating electricity.

  2. Connecting the Bicycle and Alternator

    • Connected the rear wheel of the bicycle to the alternator.
    • Carefully adjusted the mounting position to ensure the alternator would not wobble.

  3. Power Generation Experiment

    • Actually pedaled the bike to spin the alternator and measured the amount of power generated.
    • Used a voltmeter to confirm that the battery was being charged correctly.
Experimental Results and Challenges

Results:

  • Stable power generation is possible just by pedaling the bicycle.
  • With a power output of about 30W, it is suitable for charging smartphones or powering LED lights.

Challenges:

  • If the initial RPM is insufficient, power generation will not start, so the startup procedure for the entire system needs to be refined.
  • If the RPM is low, power generation efficiency deteriorates, so it is necessary to maintain the bicycle’s speed above a certain level.
  • Lead-acid batteries are somewhat troublesome to handle and dispose of.

Future Improvement Plans

  • Improving Efficiency: I aim for more efficient energy transmission by further refining the connection method between the alternator and the bicycle.
  • Lightweighting and Space-saving: I want to increase the convenience of portability and installation by reviewing the structure.
  • Expanding Applications: I aim for a system capable of storing generated electricity to run small appliances or other applications.

Closing Thoughts

Creating “Bicycle Power Generation with a LIN-only Alternator" was a very interesting experience as a project to enjoy the fusion of DIY and technology!
The content this time is at the prototype stage, and there is still much room for further development. Next time, I would like to aim for increased efficiency and improvements toward a more practical system.
If you are interested, please give it a challenge! I am also looking forward to your questions, impressions, and ideas ✨

Homemade tools and devices3D printer,CNC,DIY,HTTPS,Power outage countermeasures,conversion

Posted by 納戸工房