77 CB750 Regulator/rectifier

[zedx]

Trying to get back into the bike build and I have been wondering something for some time. I want to upgrade to a regulator/rectifier combo but I don't want to spend $100. My question is can I use on from a GL 1100? its a 7 pin just like the one for the 750 but more than half the price. I made my own wiring harness so connectors are not a big deal for me.

 If not is there any others out there that people have had success with?

[kandrtech]

Nope, won't work.

The GL1100 charging system uses permanent magnets in the rotor - the CB750 uses a field coil (that the GL1100 doesn't have) - that must be "charged" by the regulator.

[Re-run]

I will try to look tomorrow but I have found docs that say how to make 1 for very cheap. Like 20 bucks or something like that.

[shinyribs]

Since you are not concerned with having a matching factory connector could you use one of these?

It is 3 phase.  $16 shipped.

http://www.ebay.com/itm/Voltage-Regulator-Rectifier-Honda-Spacy-CH-125-Elite-6-wires-3-phase-12V-/170856910311?pt=Motorcycles_Parts_Accessories&hash=item27c7dd8de7&vxp=mtr

[zedx]

That will really work!? Its only a 6 wire what wire is it missing? I believe all the 750 SOHC's are 7 pin. I would be very happy if I could have a new one for only $16!

[TOOLS1]

Why not switch to a DOHC reg/rect? There is information on the web that tells how to do it.
TOOLS

[shinyribs]

I'm pretty sure a 6 wire will work. But it would be best to get a diagram first.

No R&R knows what bike it is attached to, only what you tell it to do.
IIRC, one the  wires in the original harness is used to activate the field coil (the magnet mounted inside the stator), so that 7th wire just be something you can wire separately,rather than having it lumped in with the others like the factory did. I really wish I had a SOHC in front of me to look at right now.

That R&R in the link has three yellow wires in the one harness that will connect to the three wires coming out of your stator. That handles the rectifier portion.

The other harness has red,black and green.

Chances are red will go straight to the battery ( for the voltage regulator portion) and green will go to ground. The black wire will probably hook to switched "+". Thats how you deactivate the voltage regulator from trying to operate/draining the battery when the bike is off.

I can't swear that the above color descriptions are correct, just what I'm thinking. You could message the ebay seller and ask for a wiring diagram. But it IS a three phase (three yellow wires) R&R, which is all you need.

Maybe this will help some.

[shinyribs]

Here is another option if you are not opposed to funky wiring and mounting your own parts. For less than $4.

http://www.ebay.com/itm/Bridge-Rectifier-3-Phase-Diode-35A-Amp-1000V-SQL35A-NEW-/331150173857?pt=LH_DefaultDomain_0&hash=item4d1a16a6a1

^^That is an AC-to-DC,3 phase rectifier. It's $0.99. It's rated at 35 amps,which is more than double what these bikes produce.

I had a similar unit ( mine was single phase) on my drag car and it never gave any problems. I mounted it directly in front of the radiator for plenty of air flow and it stayed cool. In front,but definitely not touching. Mine was actually much smaller than the one in that link. Here it is.

http://www.ebay.com/itm/DC-12V-24V-to-5V-20A-High-Current-Buck-Voltage-Regulator-Car-LED-Power-Supply-/351018868861?pt=LH_DefaultDomain_0&hash=item51ba5ae07d

^^ That is a 12v voltage regulator. It's $2.63. Wiring diagram is on the back.

The voltage regulator is the component that creates the most heat,thus the finned body. It has to ''shed'' the excess voltage which leaves in the form of heat. You probably already knew that,though.



If you go to ebay and search for ''ac to dc rectifier'' or ''dc voltage regulator'', but search in the electronics section vs the motorcycle or automotive section, you'll see just how cheap electrical components actually are. Good luck!

[shinyribs]

This may be of some help,too.

http://forums.sohc4.net/index.php?PHPSESSID=idrro68fqbqf87929gpdqdi5c1&topic=121646.0

[Re-run]

That was the one I was looking for. Pinhead did a lot of stuff to his 650.

[sgtslag]

Shiny, All,

That second voltage regulator, reduces 12-35 Volts DC, down to 5 Volts, and up to 20 Amps...  It is not a 12 Volt Regulator, it only puts out 5 Volts.

Aside from that, there are 12 Volt Regulators, some capable of handling 35+ Amps, made by electronic suppliers.  Yes, you can use them for bikes, but you need to choose one with the correct amperage, voltage, and a proper heat sink.  Same for the Rectifiers:  those referred to, will work.

I love the Voltage Regulator from a car/truck, for bikes.  The only issue of concern is proper heat sinking, to avoid burning them out.  If you want to pursue using these devices, let me know, and I can offer some assistance with the heat sink issue.  Cheers!

[zedx]

Wow, thanks everyone for all the great info! I think I am going to give the ebay 6 wire rectifier/regulator Shinyribs mentioned. I'm sure I will be back on here asking for some advise when I get the diagram and part. Thanks again!

[sgtslag]

The 6-wire device is only a Rectifier -- it will not Regulate the voltage.  Here are the differences between the two devices:

Rectifier:  converts AC voltage to DC voltage; the output is a wavy voltage, oscillating between a minimum, and a maximum voltage, what is called, Peak-to-Peak voltage, sometimes referred to as a saw wave; the hi/lo can vary by several volts, and this is not good for your bike's electrical system, as the voltage varies at a high rate, upwards of 30 cycles per second; it's DC voltage, with a lot of ripple (the saw wave).

Regulator:  smooths out the voltage variations/peaks, to a lower, steady-state, flat-line voltage, which rises/falls slowly (no ripple), based on the input voltage; to do so, it reduces the voltage below the minimum output of the Rectifier, which prevents fluctuations from affecting it -- that's how it keeps it flat-lined and steady; with an input voltage of 18-25 Volts, you can regulate it up to around a maximum of 17 Volts, any higher, and you get ripple (bad).

You need a Rectifier, to convert the Alternator's output from AC, into DC; you also need a Regulator, to reduce the DC voltage to an acceptable level (<16 VDC), and to remove the ripple voltage to a smooth, flat-line voltage.  Bikes combine these two electronic devices into one unit, with a heatsink to dissipate the heat they generate.  Cheers!

[zedx]

That makes sense. Are you saying this description is wrong? It stated that it is a Regulator/rectifier.

http://www.ebay.com/itm/Voltage-Regulator-Rectifier-Honda-Spacy-CH-125-Elite-6-wires-3-phase-12V-/170856910311?pt=Motorcycles_Parts_Accessories&hash=item27c7dd8de7&vxp=mtr 

[sgtslag]

Sorry, I was looking at the other links, apparently.  That is the full module, containing both a Regulator, and a Rectifier.  The links I was looking at were for a three-phase Rectifier, and a 5 Volt Regulator.

The unit you are referring to looks to be made for a much smaller bike, a CH 125?  If it is the same components used on your bike's OEM unit, then it will be fine; if it is much smaller in amperage capacity, it will burn open very quickly.  Cheers!

[shinyribs]

It's a good thing Sarge is here to clear the mud.