Do reg/rec's get hot?

[RVFHooligan]

So, when I finally fired up the bike last weekend, one of the things I checked was the regulator/rectifier. I had all the bodywork off at the time so this is why I noticed it. Do they normally get hot to the touch? Not scalding hot that you would burn your fingers, but hot enough to notice. Inquirying minds want to know.

[V4Chris]

yes, that's what the cooling fins are there for

take a read of this...

What precisely is the function of the regulator/rectifier? Does it perform two separate functions, as the name implies, or just one?

It does indeed perform two separate functions. The power coming from your alternator is 3-phase AC power. Each of the three wires coming from your alternator carries AC power, but in each wire the phase is different. It is the job of the rectifier part of the reg/rect to convert the power from 3-phase AC to single-phase DC.

The DC power will not necessarily be at the correct voltage to charge the battery. The alternator always tries (for a given engine RPM) to put out the same amount of power. Since power is equal to volts times amps, if the bike is not using much current (battery fully charged, no heavy electrical loads), the voltage will rise. It is the job of the regulator to supply the load so that the voltage is kept within specified limits. It does this by consuming the excess electrical power as heat.

source

[RVFHooligan]

Thanks Chris! Good info. I just wanted to make sure I wasn't burning up a brand new reg/rec.

[fastdruid]

This is also why IMO it's a good idea to put some heat sink paste on it and make sure it has a good smooth surface to sit against so that the frame acts as a heat sink.

Druid

[wullvfr]

v4 chris.......nice little quote,very handy info!!!!
the standard reg rec relys primarily on dissipating heat through the frame if the battery is fully charged etc.but these aftermarket reg rec or the ones from other bikes that have the cooling fins are much better at keeping cool and i think this is why they last longer and everyone seems to fit them.
a tip that i picked up from here is always have your lights on as this will help keep it cool.........


william

[Psychosomatic88]

I clever trick I seen on a bike is also to use a small ali heat sink such as found in old computers etc to give extra cooling potential

[abiggs82]

and the fans aswell.....

[keithcar]

a tip that i picked up from here is always have your lights on as this will help keep it cool.........


william

good advice, and i imagine with the j-spec bikes only having 35w headlamp bulbs doing a conversion over to 55w would help as well.

[Neosophist]

Hmm

I'm going to buck the trend and say I don't know if thats good advice.

If you make short trips, running with the lights on will leave the generator with less available power to re-charge the battery, making the system work harder.

I don't usually drive with the lights on unless visibilty is comprimised.

Mind you I do have a reg/rec with fins on it.

If I was that worried about heat i'd relocate the reg/rec to somewhere in the nosecone / near the front rad to ensure that there was a good supply of air running over it ^_^

[wullvfr]

If you make short trips, running with the lights on will leave the generator with less available power to re-charge the battery, making the system work harder

i see where you are coming from with this,but i do not believe this to be true.
or maybe i am wrong lol!!!!!


william