In regards to the generic rectifiers, there has been some discussion, as you will find in the suggested threads, of the super-cheap ones from China going bad.
I would be careful in getting one, and perhaps select an item that has been solidly recommended by members.
I put one together from Radio Shack rectifiers 5 years ago, and its performing fine. Then I installed this one
Brand New SQLF30A Bridge Rectifier 3-Phase Diode 30A 1200V
( 400714167691 )
($3.65 from dealbestshop in China) in my '75, and it makes me a bit nervous, altho it is functioning well at the moment. It might be one of those "super-cheap" and fragile items.
I've got a "couple more" of so many parts, but for some reason I failed to get a couple more of those..That's exactly what I am running and I have had no problems with it. After I got everything up and running I thought, what the heck at $3.65 a pop, why not go crazy and order a couple more! And that's exactly what I did. I don't expect it to fail but if it ever does , I've got a couple back ups!
And oh yeah, I'm running an automotive VR-115 with that.
I've got a "couple more" of so many parts, but for some reason I failed to get a couple more of those..
And the seller no longer has any...
But I've still got a couple more Radio Shack rectifiers.
Am I correct, Bob, that if this Chinese bridge rectifier goes bad, the symptom will be that charging will drop down from the usual charging rate?
Thanks 5T,Yes, the charging rate will decline or possibly stop completely, depending on how many of the diodes in the rectifier have gone bad. These 3 phase rectifiers contain 6 diodes wired up in pairs. One of the white wires from the alternator connects in between each pair. If one pair of diodes has gone bad, you'll only get about 2/3 of the charging output, 2 pairs about 1/3, etc.
Diodes are like one-way filters or "gates" for current flow. The AC, or alternating current being fed in on the white wires flows back and forth, or in both directions. The diode pair only lets one direction of that current flow through. So, what you get coming out is DC current flow. Here's an excerpt from an early manual that explains it pretty well .....
I see nothing wrong with these cheap units, as long as a rash of failure reports don't start cropping up. The fact that they come built on a heat sink already is one of the things that attracted me to them. There is another option, a unit used on some other Yamaha models, the XS500 in particular. This is a more modern, totally sealed unit and looks quite nice. All that is required for 650 use is changing the plug, female to male connectors .....