Recifier subsitute

[Normk]

In case anyone is looking for an alternate source for a rectifier, I have used the unit from Delco Remy 10SI automotive alternators for various projects over the years:

http://www.ebay.ca/itm/New-Rectifier-10SI-20-SI-Delco-Alternator-/230634209246?pt=Motors_Car_Truck_Parts_Accessories&hash=item35b2debfde

These ground to the heat sink and the three studs in the central row connect to the stator wires. They are rated at up to 100 amps depending on the supplier and the price is very attractive. I've hung them from many motorcycles, power equipment and such where a rectifier is needed. These are intended for three phase but can be used for one, two or three wire stators and two can be combined for four wire alternators such as some of the Nippon Denso.

Just in case it is useful to someone.

There are a number of voltage regulator plans on the net, including the one from BikeCliff's site which can serve in place of an expensive OEM regulator but it seems to make little sense to assemble a rectifier when the 10SI unit is so inexpensive.

HIH

Norm

[tom203]

I venture that most folks on here would like to keep charging as simple as possible- a combo rectifier and regulator is a nice solution. Used Shindengen R/R's are very cheap , proven reliable,and designed for a low output 3 phase systems that are typical on these old bikes. 100 amp diodes are overkill - we have more concerns about frying our stators even with little diodes. A even better, but pricey, R/R can be had from Compufire to further reduce stator stress.

[OldVet66]

I'll second the Compu-fire, but it isn't a budget fix by any manner of means, but it does seem to present a solution to the age old unreliability of these antiquated shunt type R/R's.

[kb_air]

ok, but is there anyway to test a plain old rectifier, not combo part?

[Steve]

ok, but is there anyway to test a plain old rectifier, not combo part?

Yes there is.

If your meter has a "diode test" function you can use that, if it doesn't, you can use the ohmmeter function.

Your rectifier will have five wires: three input wires, positive and negative 'output' wires.
Using the diode test, connect your black lead to the negative wire, then touch each of the stator inputs with the red lead. You should see no reading (might read zero or OL or OR for overload or over-range). Connect the red meter lead to the negative wire, then touch the black lead to the stator wires, you should see a reading of .5 or .6, which is the turn-on voltage of the diode.

Repeat the same tests on the positive wire.

Overall, you will do 12 tests. Six of them should have readings of .5 or .6 (or so), the other six should be zero or OL. If you don't have 6 of one and 6 of the other, you have a bad diode.

By the way, you do this same test to check a combo R/R unit. In fact, it's the only test you can do to the R/R except for the output voltage.

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