- #1
knightscape
- 3
- 0
Hello, this is my first post here! I am building a bicycle-driven generator using an alternator and battery (12v) pulled from a dead car. I can easily spin it up to the point where the alternator self energizes and produces output, but on a dead or low battery, the load on the alternator is so high that it is unsustainable for more than about 5 minutes. After reading various sites describing how to accomplish what I'm trying, I've found that by adding several resistors in parallel on the alternator output line, I am able to limit the production of the alternator to levels I can actually pedal for an hour, around 0.9a (the idea here is to capture power during my normal workout on my stationary bike). I had a few resistors in my bin, so what I've added in are two 10Ω 10w and one 8Ω 20w resistor in parallel. These total up to just over 3Ω. By decreasing the resistance I should be able to let the alternator produce a bit more power, but I honestly don't understand why this is so or how I can calculate the optimal resistance to aim for. I would appreciate any guidance or advice to help me understand why these resistors help keep the alternator pedalable and how to dial it in for optimal output.
Here's my setup, except I cleaned up the giant roll of wire on the output line today:
Here's my setup, except I cleaned up the giant roll of wire on the output line today: