Regulator 6V 3W for a Hub Dynamo bicycle

This is a regulator for a 6V/3W bicycle hub generator system. The purpose is to manage the powering of bicycle lights from the hub generator and from rechargeable batteries, to charge the batteries using excess power from the generator, and to provide intelligent charging of the batteries from an AC adapter, when needed.

The switch has three positions: charge-off-light. In the charge position, the bicycle dynamo charges five AA NiMH batteries if those are drained. If the batteries are reasonably full, then the circuit draws virtually no power. In the light position, if the dynamo’s average voltage is below some threshold value, then the bicycle lamps are fed by the batteries aided by the rectified dynamo If the dynamo voltage is high, the lamps are fed directly by AC from the dynamo and the dynamo excess power is used to recharge batteries. The direct use of AC maximizes efficiency. Additional circuitry is provided for an intelligent charging of the batteries from an outlet using a 12V AC or DC adapter. Practice shows that that additional circuitry may be redundant. A flickering green LED indicates the activity of the dynamo in the charge mode and the fact that the light is fed by AC in the charge mode. A red LED indicates the fast charge state when the charging is done from an outlet.

Source: http://www.nscl.msu.edu/~daniel/sreg.htm

Power Supply   Switching Power Supply   DC to DC Converter   Inverter
Battery charger   Led flasher   Motor speed controller   LM317   IC 741
RF radiofrequency   Electronic control   Digital Circuit   Alarm home system
DC to DC converter step up voltage   Mini project   Temperature control
FM receiver   Dual power supply   Fluorescent lamp   Pic microcontroller
Led display   RF amplifier   FM transmitter   LM324   LM723   TL494
2N3055   LM338   SG3525   Li-ion battery charger   Pulse generator