6 Volt Motorcycle Alternator. Possible voltage regulator?

[mrmodify]

Evening All,

I have a couple of small motor cycles the if the battery becomes disconnected or the bike is ran with out a battery- they will burn all or most of the bulbs out. They are older jap bikes. I was wondering if I could possibly put a voltage regulator on the bike to keep them from burning out the bulbs. I am assuming the battery keeps the voltage at a allowable level so bulbs can survive. I have posted both of the schematics for each bike.

Thanks

 

[(*steve*)]

The problem is that without a load the voltage can rise quite high (and may have spikes on top of that).

Yeah, a regulator would do the trick, but you need to ensure that you do not exceed the maximum input voltage for the regulator.

 

[Colin Mitchell]

The regulator would need to be 8v at 20 amp

 

[debe]

Is some years now but I had a Honda bike like that. My fix was a 10 ohm 20Watt resistor in place of the battery.

 

[Colin Mitchell]

A 10 watt load is not going to take much from a 60 watt generator.

 

[debe]

Have a look at the circuit its the same as the bike I had. A Honda NC50, 4000rpm 8.5v @ .7A. 6000rpm 8.7V 2 A. It doesn't take mutch load to simulat battery load with battery removed. It worked on my Honda NC50.

 

[Colin Mitchell]

It looks like the best way to prevent burning out the lamps is with a resistor, although you are bleeding nearly 50% of the generating capacity and the battery will take longer to charge and a 4 hour run at night will flatten the battery - if the specifications on the sheet are correct.

 

[debe]

I removed the battery when it died & decided not to replace it. That was when I found the headlight would blow, so fitted a resistor in place of the battery. The battery in the Honda was only used to power the parking lamps & inst lamp if the engine wasn't running. The head light was only run of the 2nd set of windings. But if there wasn't some load on the battery charge windings, the headlight voltage went too high. (strange setup!)