Human Powered Machine Innovations Exhibited at the 2010 Midwest Renewable Energy Fair By Working Bikes Cooperative


Three innovations are discussed in this section:
1. Using a mountain bike or Schwinn Exercycle to power appliances,
2. Using a Nordic Track to power appliances and
3. Charging a cell phone, smart phone, iPod, MP3 player or any 5 volt USB device using the 6 watt bottle dynamo on a bicycle.

Our machines have evolved in the past year. The machines are simpler to build and can power a wider range of appliances. The designs no longer use batteries. The changes are made possible by using switch mode (switching) power supplies to run low-power consumer electronics. These appliances include digital TVs, chargers for smart phones, compact fluorescent and tube fluorescent lamps.

The machines also power kitchen appliances and shop tools with universal motors such as blenders, angle grinders and drills. The machines we design are instant gratification human power gen-sets. One can use the machines to make a smoothie, watch TV, sterilize water, provide light in the library or on the soccer field and charge hand held devices.

One can charge a battery using a bike machine and a solar charge controller but our designs do not use batteries. To charge and retrieve energy from a battery one loses much of the energy. Using batteries also more than doubles the expense of the apparatus due to the need for a charge controller and inverter.

Designing without batteries is made possible by using switching power supplies for each appliance. Formerly consumer electronics were powered by transformers. Transformers however do not work with DC generators. Now they are powered with switching power supplies which will take a wide range of DC input voltages from 0 to 240 VDC and supply their respective appliances with the voltages they require.

Voltage and Appliance Chart
Voltages (DC) – Appliance

0-20 – Solar Charge Controller
20 to 240 – 120 volts to 5 volts USB adaptor
50 to 240 – 120 volts to 12 volts DC adaptor for a digital TV
60 to 240 – Compact Florescent Lamp
90 to 240 – Tube Florescent Lamp
100 to 140 – Blender, coffee grinder, sewing machine
(Do not exceed the voltage accepted by an appliance).

1. Using a 26” wheel mountain bike or a Schwinn Exercycle to run appliances.

We combine the instructions for the mountain bike with the Schwinn Exercycle because they achieve about the same RPM and therefore the same voltage. The Exercycle has a smaller 20” wheel. However it has a large chain ring at the crank. This allows it to achieve a high RPM comparable to that of a mountain bike.

Put the mountain bike on a bike trainer. There are several bike trainers on Amazon.com for less than $100.

Construct a “skid” from a 1” thick piece of plywood or 1 ½” boards large enough to fit under the trainer.

Place a DC generator on the skid..

Put a V-belt around the rear wheel of the bike or the Exercycle.

It is advisable to first position the parts of your apparatus before connecting them to the skid. Then use a string around the wheel and the sheave to get an accurate measurement for the belt.

We use an 88” belt for the mountain bike and a 68” belt for the Exercycle.

Put the smallest possible sheave (pulley) on the shaft of the DC permanent magnet motor (generator).

Position the trainer or Exercycle on the skid so that the belt is tight.

The belt should not touch the trainer.

Air can later be added or removed to the bike tire to adjust belt tension.

The belt does not need to be on very tight because we are only going to generate power in the range of 0 to 200 watts (unlike the belt tension in a car).

The belt will stay on the tire because it climbs to the highest point at the center.

Block the trainer or Exercycle in its desired position with pieces of wood or aluminum tubing or channel.

Cut off the plug of an extension cord and connect the wires from the remaining extension cord to the two wires from the generator.

Start pedaling. Use a voltmeter to see what voltages are possible from you apparatus.

The voltage will determine which appliance one can power.

Consult the voltage appliance chart to see what voltages are required by various appliances.

2. Using a Nordic Track Ski Machine to run appliances.

Mount a generator (DC permanent magnet DC motor) to a 2’ x 2’ sheet of thick plywood.

Place a belt around the steel wheel of a Nordic Track.

If using a treadmill motor use a surpentine belt that matches the fan’s sheave (pulley) on the generator. http://www.grainger.com/Grainger/items/3X542?Pid=search

If using a treadmill motor with a fan and a serpentine sheave make sure the rotation of the fan is in a direction to tighten it to the shaft to prevent it from coming off during operation.

If using an electric scooter motor or another motor use a v-belt and put a v-belt sheave on the shaft of the generator.

Use the smallest sheave possible for a shaft to get the maximum RPM.

Place the rear of the Nordic Track on the plywood square.

Place the belt around the sheave.

Position the Nordic Track so that the generator is toward the back of the Nordic Track with the rear casters on the “skid”.

Position the Nordic Track so that the belt is tight.

Put blocks of wood or aluminum channel around the casters to keep the Nordic Track and skid in position.

Cut off the plug of an extension cord and connect the wires from the remaining extension cord to the two wires from the generator.

Start skiing.

Use a voltmeter to see what voltages are possible from you apparatus.

Consult the voltage appliance chart to see what voltages are needed by various appliances.

3. Charging a cell phone, smart phone, iPod, MP3 player or any 5 volt USB device using the 6 watt bottle dynamo on a bicycle.

Bottle dynamos found on many bikes are low-power AC permanent magnet generators. They can be harnessed to charge any USB device.

We use European style connectors to put together the following circuit.
http://www.radioshack.com/product/index.jsp?productId=2103986

Convert the dynamo AC output to DC using a full wave bridge rectifier from Radio Shack
http://www.radioshack.com/product/index.jsp?productId=2062581

Place an electrolytic capacitor across the DC output from the rectifier
http://www.radioshack.com/product/index.jsp?productId=2103610

Connect the DC output to a female AUX (cigarette) connector. Make sure that the center (tip) is positive and the outside is common (ring).

Plug in a 12 VDC to USB adaptor.
http://www.harborfreight.com/catalogsearch/result/?category=&q=usb

The resultant circuit should work like the following:

Generator -> full wave bridge rectifier -> capacitor (in parallel with the DC output) -> 12 VDC female connector -> 12 VDC to USB adaptor