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LED BIKE LIGHTS : LED BIKE
Led bike lights : Chinese bikes : Cyclocross bike reviews.
Led Bike Lights
- The lungs of sheep or pigs used as food, esp. for pets
- (light) lightly: with few burdens; "experienced travellers travel light"
- (light) make lighter or brighter; "This lamp lightens the room a bit"
- (light) (physics) electromagnetic radiation that can produce a visual sensation; "the light was filtered through a soft glass window"
- bicycle: a wheeled vehicle that has two wheels and is moved by foot pedals
- A bicycle or motorcycle
- bicycle: ride a bicycle
- motorcycle: a motor vehicle with two wheels and a strong frame
- Light-emitting diode, a semiconductor diode that glows when a voltage is applied
- light-emitting diode: diode such that light emitted at a p-n junction is proportional to the bias current; color depends on the material used
- (ling) heather: common Old World heath represented by many varieties; low evergreen grown widely in the northern hemisphere
- (ling) water chestnut whose spiny fruit has two rather than 4 prongs
LED bike light generator
This shot of the stepper motor-as-generator shows the clearance under the frame.
Cheap unipolar stepper motors make surprisingly good generators for powering LEDs. Just connect one terminal of the LEDs (polarity doesn't matter- the current from the motor is AC) to the red wire (sometimes there are two red wires, just connect them together), and the other LED terminal to one of the other wires. It's that easy!
Each of the four coils of the stepper motor generates 3.2 VAC at about 800 RPM, with a load of ~175 mA (seven LEDs in parallel, each pulling 25 mA). The motor/generator should run at least 28 LEDs using all four coils.
Each coil produces 12 pulses per revolution, with a 50% duty-cycle,. In other words, one LED hooked to one coil will produce 12 flashes per rotation and at 1 revolution per second, each pulse is .04 seconds long ( 1 / 12= .083, .083 / 2= .04). Because the LED is on only half the time, the peak voltage to the LED can be higher than it's rated continuous value.
DIY LED bike-light
This is the bar of LEDs that I drive with the generator made from a stepper motor (see my other pics of this project for more info).
The LEDs are inserted into a hard-drive ribbon connector (removed from the cable- the hole spacing and size is perfect for standard LEDs). I used hot melt to cover the wiring for moisture resistance. I'm still looking for just the right housing for it.
See also:
electric start pocket bike
yamaha 50cc bike
racing bmx bike
carbon fiber bicycle forks
huffy 626 road bike
giant bicycles for sale
dog bike carriers
Post je objavljen 28.11.2011. u 14:15 sati.