Spin Bike Generator

For power savings measures, we were not allowed to have Christmas Tree lights, so I decided to build this spin bike generator to light up the tree and blow up the Santa, all while being able to charge your mobile phone as well.

• used Spin Bike (got it for free)
• 140kV RC motor
• Digital LCD Voltmeter
• MPPT Wind Controller
• Flexible Coupling Coupler with 65mm wheel
• DC CC 9A 150W 300W Step Down Buck Converter 5-40V To 1.2-35V
• Dual USB Ports Car Charger + LED Voltmeter + 12-24V Power Socket
• 10m of 16AWG cable
• Three Phase Rectifier Diode
• 12V Lead Acid Battery
• Bidirectional Powerbank
• 12V-5V USB Adapter

Attach the generator to the bike - I followed more or less these instruction:

https://www.instructables.com/Spin-Bike-RC-Motor-Pedal-Generator/

He's really clear and with a bit of improvising, according to the bike you have and what other supplies you can get, it can be easily constructed.

I hooked it up to the rectifier diode and then to my voltmeter. It is easy to get to 13-14V, but if you spin quickly, it shoots up to almost 30V. I added the buck converter in order not to fry my USB charger and the 12V plug.

For the Chrismas lights, I hooked up the power bank with a small USB charger inside. Because it will stand in a public place with kids around, I make a little cover for the spinning wheel and generator, so no curious fingers will be injured.

Unfortunately, after a day, some kids spun so hard, my buck converter fried and let through all the voltage, which in turn fried the LEDs and fan on the inflatable. I solved this problem by connecting a MPPT wind charge controller, which limits the power nicely to about 13-14V max, and "brakes" the generator if the voltage (rpm) gets to high, which is very much audible can be immediately felt. Not ideal as it will stress the components, so I will go ahead with a more robust buck converter "before" the wind controller, so the braking will only be activated in "emergencies", such as a (again) fried buck.

So far, many happy faces inflating Santa and lighting up the tree. After Christmas, the plan is to leave to bike with a number of USB charging cables hanging out for everyone to charge their phones with Pedal Power!