What happens to the bikes electrical system with burnt out lights or lights turned off?

[Breaker19]

So after the headlight bulb on my XR600R burned out the other day it got me thinking.  What happens to the juice the stator is making when the light is out? 

Normally the light would be discharging the electricity the bike is making but with the bulb burnt out or I've been thinking about installing a on/off switch.  Whats happening with bike?

Can running the bike without some of its stock lights damage other parts of the electrical system?

 

On the flip side if I was to hypothetically add more lights to the electrical system and draw more amps.  What kinda issues or damage can be caused?

Just trying to get a better understanding of how motorcycle electrical system works.

[Hollerhead]

As electrical loads decrease any excess produced is sent to ground and turns into heat that is dissipated through the regulator heat sink.  As long as the airflow is decent across the regulator it shouldn't hurt anything.

The stock system can't handle much in the way of an increase in loads.  Not many accessories can use the AC current produced anyway.  Some lights will work fine on it though.  Increasing loads too much will cause excess heat to build up on the charging section of the stator and will likely result in a shorted stator winding showing up fairly quickly.  The good thing about the R's system is it usually won't leave you stranded as the ignition power comes from its own dedicated section on the stator.

 

 

Edited September 24, 2017 by Hollerhead

[heart_of_darkness]

Any electricity not consumed by the accessories gets converted to heat in the regulator.  I don't know just how much heat it can withstand, but if / when my headlight goes out I always disconnect the stator output wires to break the circuit.

[Breaker19]

Awesome!  Thanks Hollerhead, that makes sense that the regulator is discharging the extra energy as heat.  I kinda figured this was the case but didn't know where in the system it was happening.

Although this leads me to wonder what's happening next if the wires are disconnected like heart_of_darkness suggested and there is no regulator or completed circuit?

I've added a rectifier and capacitor for the tail light so I could run LED running and brake lights.  And learned a lot about electricity/this motorcycle's systems in the process.  One of these days I'd like to do something similar to the headlight so I could run a brighter more robust light and ditch the incandescent bulbs.

Thanks guys!

 

[Hollerhead]

4 hours ago, Breaker19 said:

...Although this leads me to wonder what's happening next if the wires are disconnected like heart_of_darkness suggested and there is no regulator or completed circuit?

I've added a rectifier and capacitor for the tail light so I could run LED running and brake lights.  And learned a lot about electricity/this motorcycle's systems in the process.  One of these days I'd like to do something similar to the headlight so I could run a brighter more robust light and ditch the incandescent bulbs.

Thanks guys!

 

When the alternator is disconnected from the regulator there is voltage produced but no current flowing.  No current = nothing to shunt to ground.  The alternator just hangs out and spins as freely as is possible for a permanent magnet type.

It sounds like you've already done so on a small scale but go ahead and convert the bikes whole power side to DC by using a rewound stator (or rewind your own) with greater capacity.  It opens up a whole world of cheap and easy possibilities for lighting and accessories.  I'm not sure how much power is available out of the rectified stocker but with the charging system options available in the aftermarket it's an easy, and fairly inexpensive, conversion to a strong system.

[Breaker19]

Cool!! And thanks for your insight!

And yeah this bike is plated and I wanted a larger brighter rear/brake light.  The LED tail light is just a cheap generic motorcycle light I got on Ebay but it uses less amps then the 2 incandescent bulbs stuffed into the tiny little fender light.  I've been using the bike for commuting a lot this summer(30 miles a day or so) and the tail light has been working really well.

[JoeRC51]

57 minutes ago, Hollerhead said:

When the alternator is disconnected from the regulator there is voltage produced but no current flowing.  No current = nothing to shunt to ground.  The alternator just hangs out and spins as freely as is possible for a permanent magnet type.

It sounds like you've already done so on a small scale but go ahead and convert the bikes whole power side to DC by using a rewound stator (or rewind your own) with greater capacity.  It opens up a whole world of cheap and easy possibilities for lighting and accessories.  I'm not sure how much power is available out of the rectified stocker but with the charging system options available in the aftermarket it's an easy, and fairly inexpensive, conversion to a strong system.

All stators produce a/c voltage , the rectifier changes the a/c to d/c. No rectifier and you have a/c. 

[Hollerhead]

18 minutes ago, Breaker19 said:

Cool!! And thanks for your insight!

And yeah this bike is plated and I wanted a larger brighter rear/brake light.  The LED tail light is just a cheap generic motorcycle light I got on Ebay but it uses less amps then the 2 incandescent bulbs stuffed into the tiny little fender light.  I've been using the bike for commuting a lot this summer(30 miles a day or so) and the tail light has been working really well.

I did some work on this 600R for a customer a while back.  It was the first DC conversion I'd done and I was really happy with how easy it was and he loved that he could choose any light he wanted.  The small battery pack is laying in the tray under the seat.  He planned on riding it on the street but he never could get the hang of starting it even after the new carb and all.  I think it's down in Texas somewhere now and I hope he was able to finish it. 

Edited September 26, 2017 by Hollerhead

[Hollerhead]

9 minutes ago, JoeRC51 said:

All stators produce a/c voltage , the rectifier changes the a/c to d/c. No rectifier and you have a/c. 

To clarify.  He already added a rectifier so he knows he needs that for DC.  

I'm just not sure how much power the stock R alternator can produce without rewinding.  I doubt it is much.

Edited September 26, 2017 by Hollerhead