Need regulator/rectifier help

R100 · Post by **R100** » Sun Jul 27, 2014 3:55 pm

First - thanks to Hahnda. Looks like he sells a nice rectifier replacement for a good price.

Here's what I think I know -
Rectifier converts AC to DC.
Regulator limits voltage to protect the battery etc.

As delivered a CB77 has ONLY a rectifier.
Some people go with that.
Some people install a regulator/rectifier.

I am confused as to why, and which is better.

HELP!

SMBH · Post by **SMBH** » Sun Jul 27, 2014 5:38 pm

I have on of these fitted to my CB77 work very well lots of others on EBay, I understand you only need a single phase.

http://www.ebay.co.uk/itm/Universal-12V ... 5d4e0cf3f4

Hahnda · Post by **Hahnda** » Sun Jul 27, 2014 6:05 pm

The CB/CL/CA did not have a voltage regulator. It relied on the battery to regulate it, kind of. Also when you turn the lights on a second coil comes into play, so the rider is kind of like a voltage regulator as well.

Adding a voltage regulator isn't going to get you more output, what it is going to do is smooth out the spikes. Some have experienced the alternator overcharging and boiling batteries but I have never had that happen with one of these bikes. A voltage regulator would certainly help in this situation. A voltage regulator will also be useful if you have components in your electrical system that are sensitive to voltage, electronic ignitions being one of them.

A new rectifier may increase your current output as even though the old one might be working somewhat it will usually not be as good as a new one. Rectifier efficiency can degrade over time even if not being used.

rrietman · Post by **rrietman** » Mon Jul 28, 2014 12:34 am

R; your CB77 does not need a voltage regulator. the battery can take a hit once in a while and the bulbs can do the same. It really does need a modern rectifier. A solid state unit will up the charge voltage, there are lots of rectifier options out there. I get mine from Beatrice cycle, DRATV.
Good luck
Randy

cadman · Post by **cadman** » Mon Jul 28, 2014 10:57 am

The system is wired to use 1/3 of the alternator output with the headlight off. Once the headlight is ON the other 2/3 of the output is added. There is no voltage regulation. In any case the problem is at low RPM the output is too low (headlight on or not) and at higher RPM can be too high,

At any rate is is not a particularly good system. The battery is either drained (if you ride around town at low RPM day or night) or overcharged (if you are riding at higher RPM for extended periods). I have tried several different methods - A Radio Shack rectifier which works fine as just a rectifier (needs a heat sink) - a Kohler solid state regulator/rectifier from a Kohler twin. Works okay if properly installed (probably also needs a heat sink).

Lots of folks on the site will tell you the stock system works just fine. Personally I don't see how it works just fine unless you pay constant attention the to battery.

I can give yo a much more detailed explanation if you need it.

R100 · Post by **R100** » Mon Jul 28, 2014 12:25 pm

Keeping in mind that I hope to install electronic ignition and possibly some LED's, I believe I should get a unit that is both regulator and rectifier.

So far I have seen reference to the Kohler, some working fine, at least one melted.
Charlie's place shows a reg./rec. but say they are out of stock.

Hahnda · Post by **Hahnda** » Mon Jul 28, 2014 12:32 pm

I have used this reg/rec on other bikes, not any of the CA/CB/CL's though.

http://www.ebay.com/itm/390575473945?_t ... EBIDX%3AIT

I think it would be as simple as tying the yellow and pink from the stator together to one of the yellow wires on the reg/rec and brown to the other yellow. Red and black from the reg/rec to pos and neg.