Regulator identification

[trickyd400]

Hi can anyone help with this? I have just bought an NC31 that needs a new regulator and battery. The one fitted was marked (original Honda) SH 633-12 and 3.1 in smaller numbers.
I have a used one (same shape & style) marked SH 609-12 and 9.0 in small numbers, this works fine as does another which has a smaller casing marked SK 30SEI98C which also works fine.
The purpose of my question is to ask what the difference is between these regulators, rating ?

Also when I refit a good one I will make sure it has good contact with the frame for heat conduction, may even fit a cpu fan!

[trickyd400]

Found this on xrv.org which explains the letters... just to need to understand how the numbers relate to case size and ratings etc.

Thanks to raymo on that forum:

The SH and the FH are both Shunt type regulator, in that they dump the excess power back into the generator windings, The generator is outputting max power all the time, hence the advice to run with lights n stuff on .

The FH used the FET Field Effect Transistor to short out the excess power and the SH uses an SCR Silicon Controlled Rectifier to do the same task the R/R has three of each in there,one for each winding., The R/R heats up due to the losses in the FETs/ SCRs it is not used as a power dump, the alternator winding are used for that,.

I did read a posting on another forum when trawling fro info where I guy had measured the current being dumped back and found that the FET, being more efficient ( less internal resistance so less heat produced ), actually dumped more current back into the alternator than the SH SCR type, but the alternator being fat copper windings in a bug lump of a motor copes..

Bottom-line is that the FET FH units are more robust and don***8217;t get as hot so cooling and location is not that much of an issue
The FH unit are used on R1s and more modern bikes, hence folk getting them from breaker yards Ebay etc.
THE FH0012 or 0008 are the best to use as they have the same mounting holes and are similar in size to the existing unit, you can fit them to any AT TA or XLV J the 0010 and 0011 are higher capacity units but fine on our bigs.. they are the same footprint as the 0012/008 but much taller..

Fitting is quite easy three ac wires in ( yellow ones)
Two out
black wire ( your choice as they are spade connectors) direct to the battery negative terminal r
Red wire , ( your choice as they are spade connectors) via a 30amp fuse to the battery positive terminal.. simples )

there is a how to on the triumph forum .. I have posted here a few times J )

Oddly enough Harleys & Big BMs have the best power systems, these are linear, it that they control the alternator and only generate what they need , these are more efficient, but then they are usually bigger 750watt units to power CDs.. Heated seat.. bling meter and sat locator for recovery van as well a wee toaster for muffins while you wait for the breakdown truck J

[thunderace]

Hence the reason for upgrading to a decent Yamaha reg/rec. FET technology is far superior