The bike with generator, light bulb switch box, and inverter circuit.
Generator and v-belt. Generator is a Leeson permanent magnet motor. We added the special outlet on top, and the red and black terminals for connecting a multimeter.
Bike with fold-down platform. The weight of the platform creates the necessary tension in the belt.
Bike with platform folded up for storage/transport.
Platform without inverter system.
Current and voltage meters.
Current and voltage meters - close up.
The light bulb switch box. The switch on the left switches between the incandescent and the fluorescent banks. The lower switches turn individual bulbs on and off, in either bank. If the generator puts out more than 12 volts, the orange light goes on and the light bulbs go off.
12 VDC 50W Incandescent bulb. These cost about $3 each.
12 VDC, 15W Compact Fluorescent bulb. We got them for about $18 each at Sundance Solar.
Circuit Diagram of the light bulb box.
Wiring of light-bulb box.
Over-voltage protection circuit and relay. Thanks to the UC Davis Pedal Powered Desk team for the design of this circuit.
Inverter box mounted on bike platform.
Inverter box close-up. A 20F ultra capacitor is used as a small amount of energy storage, which the inverter needs to start up, and which provides a few seconds of storage after pedaling stops. We put in some banana cable jacks so we can measure the currents and voltages with a multimeter, or directly charge or discharge the capacitor. We have an ammeter shunt in the line that lets us measure the total current with a voltmeter.
Inverter box. It plugs into the generator. It uses a 20F Maxwell ultra-capacitor. We have a car headlight bulb across the capacitor with a switch, so we can also use this box for demonstrations of this amazing capacitor, or use it as a simple DC load.
