Hub dynamo powered LED bike light rectification module

In recent years the incandescent lamp has been replaced gradually by LED as the leading role of bicycle lamps because of its many advantages such as smaller size, high energy conversion efficiency, rapid response, being eco-friendly, high vibration resistance, high impact resistance, being recyclable, no pollution, ... etc., as well as, with the rapid development of LED technology, its gradually decreased power consumption and gradually increased brightness.
Most modern hub dynamos are regulated to 3 or 2.4 watts at 6 volts. There was a shortcoming of using hub dynamos with great effort. However, the hub dynamo powered LED bike light will be accepted gradually in the world with trends of environmental protection and energy saving, as well as with the rapid and revolutionary development in technology, such as light-weight material, the increasing efficiency of power generation, the less and less rolling resistance, etc.

There are three issues that need to be addressed during the integration of the hub dynamo and LED bike light:
1.AC-DC converting:

The LED bike light operates on DC voltage, but the output of the hub dynamo is AC.  Hence, the rectifier will be needed in order to convert AC into DC on which LED bike light can operate smoothly.

2.Current limiting:

The hub dynamo generates unstable AC with the bicycle speed.  The faster the bike speed is, the greater power the hub dynamo generates. When the bicycle is at a very high speed, the lamp will burn out. Therefore, the current limiting circuit will be needed to protect the LED bike light.

3.LED Bike light flickering at low speed:

LED bike light rectifier modules on the market today only can allow the bike lights not to flicker at the speed of 10-12 km/ hr.

 ●No flickering

Allowed bike light to be lit with flashing at low speed (4-5 km/hr)

 ●Current limiting


Applicable to different watt LEDs, and extended the life of LEDs
  ●Test videos:The test videos that show the degrees of the flicker of LED bike light with or without ULTRAPACK supercapacitor-based filter circuit.
Without ULTRAPACK supercapacitor-based filter circuit.   With ULTRAPACK supercapacitor-based filter circuit.


  • Dimensions:30 mm (L) x 30 mm (W) x max. 15mm (T)
  • For 6V/3W、6V/2.4W hub dynamo
  • For 1W/3W LED
  • Adjustable current limiting :
   - Current range:  0.15A ~ 0.9A
   - Suggestions
     0.35A for 1W LED Bike Light Sets
     0.70A for  3W LED Bike Light Sets