XSNate
XS650 Addict
If I put a vr115 regulator is it necessary to replace the rectifier? My experience is that a rectifier either works or it doesn't , agree?
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Rectifier regulator?
- Thread starter XSNate
- Start date
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- Tags
- electrical
Have a close look, usually see corrosion on the terminals, means more resistance. Change one why not the other and if you built your own the cost is minimal.
XSNate
XS650 Addict
I will look for a 3 phase recto. Then dig around here for a diagram. I imagine it will be similar to the 2 bridge recto wiring?
No, I can't agree with that. Your old stock rectifier may still be working, but it has deteriorated over the years, and it will have increased voltage drop, which leaves less voltage for the bike.
Modern silicon diodes as used in 3 phase rectifiers or bridge rectifiers, work much better and have less volatge drop.
pamcopete
Ride.Enjoy.Life is Simple
Old original rectifiers are a leading cause of rotor failure. As RG says, they develop a larger voltage drop with age and that means that the regulator will increase the average current to the rotor to maintain the correct voltage on the brown wire. This larger current in the rotor makes the rotor run hotter which shortens the life of the winding. You can replace the rectifier for less than $10 which is more than 10 times less than the cost of a new or rebuilt rotor or 20 times less than the cost of a PMA conversion.
The next biggest cause of rotor failure is the voltage drop across the contacts of the ignition switch. The regulator monitors and maintains the voltage on the load side of the switch (brown wire) but the output from the rectifier is on the source side of the switch (red wire) so if you drop say 1 Volt across the switch, then the regulator will cause the output from the rectifier on the red wire side to make up the difference and it does this by increasing the current to the rotor. In addition. this higher voltage on the red wire side of the ignition switch is also where the battery is connected, so the battery gets too high a voltage, shortening its life as well.
So, by properly maintaining your ignition switch and installing a $6 replacement for your rectifier, you can extend the life of your rotor and battery.
The next biggest cause of rotor failure is the voltage drop across the contacts of the ignition switch. The regulator monitors and maintains the voltage on the load side of the switch (brown wire) but the output from the rectifier is on the source side of the switch (red wire) so if you drop say 1 Volt across the switch, then the regulator will cause the output from the rectifier on the red wire side to make up the difference and it does this by increasing the current to the rotor. In addition. this higher voltage on the red wire side of the ignition switch is also where the battery is connected, so the battery gets too high a voltage, shortening its life as well.
So, by properly maintaining your ignition switch and installing a $6 replacement for your rectifier, you can extend the life of your rotor and battery.
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WELDFAN
XS650 Enthusiast
so could a slighlty higher amp cause the reg/rect to get a bad reading n send a low voltage to the rotor?? im only getting 10v from reg/rect to rotor... i replaced grounds and connections thinking maybe bad connection/ground causing reg/rect to get a bad reading n send a low volt to rotor but no change..popped in a new reg/rect just to find right out the box its still sending only 10v to the rotor..im starting to think having switched to a gel pack battery that maybe for some reason its too strong n allowing too much amp to the reg/rect?? checked the fuse for the power to reg and it was fine but was on the bit too hot side but not kicked..was thinking maybe bad fuse just isnt kicking allowing too much to the reg/rect so its doing its job n sending less volts??
Sounds like you have a 1980 to 83 bike. If you are only getting 10 volts at the right (inner) brush, then you have a large voltage drop coming from the battery. Voltage at the right brush should be within 0.5 volts of the battery voltage.
A little hard to understand your description, but do you mean your fuse was hot? If so, a hot fuse/fuseholder is what happens when the resistance goes up. If you have the old original fuse holders (clip type with glass fuses), they are well worn out and should be replaced with automotive blade type fuse holders asap.
As pamcopete mentioned, the ignition switch can also have its resistance increase, and cause voltage drop. On my bike, I've had to open up the ignition switch and clean the contacts, due to higher than normal resistance. Ignition switch should have 0 resistance.
RG, can you elaborate on this "voltage drop" thing with the rectifier? Is it something I can test my rectifier for? I have the replacement made up, just not installed yet. Have the VR115 ready to go as well but same deal, just not installed yet. The bike charges fine still with the original components but I'd hate to be putting undo stress on my rotor.
All rectifiers/diodes have a voltage drop due to internal resistance (physics etc). They do there job with the voltage drop being normal, and with the voltage drop/resistance producing heat.
The old selenium type rectifiers had about 1 volt voltage drop, while the modern silicon diodes have only 0.6 or 0.7 volts voltage drop. So the newer diodes are more efficient, consuming less power themselves, which leaves more power available for the bikes loads.
I've never done a direct comparison of old versus new rectifiers for voltage drop. If you did do a comparison, i.e. bike at 3000 rpm , having exactly the same AC voltage into the rectifier, the modern diodes would have a higher DC voltage output, and less heat.
The old rectifiers were quite reliable, so its not surprising that yours still work. My old rectifier was still working when I removed it.
Further to what Pamcopete was saying, I recommend you disconnect your ignition switch and measure its resistance. Use the lowest resistance scale. The ignition switch resistance can go up to 0.8 ohms of more. When the copper contacts are clean you should read 0.0 ohms. That low resistance across the switch will let the regulator do its job, while keeping the rotor current as low as possible.
I think I might install just my new rectifier for now and see what effect (if any) that has. My ignition switch should be good because I took it all apart, cleaned it, and dielectric greased the parts when I got the bike.
I have one of those L.E.D. charge indicator lights from gggGary installed and while the charging seems good, it sometimes is not consistent. The light is green at my normal cruising RPMs most of the time but sometimes it's not. It goes orange occasionally indicating a lower charge rate. I'm leaning towards the old mechanical regular as the culprit for the inconsistent output but would like to upgrade just one component at a time to see.
I have one of those L.E.D. charge indicator lights from gggGary installed and while the charging seems good, it sometimes is not consistent. The light is green at my normal cruising RPMs most of the time but sometimes it's not. It goes orange occasionally indicating a lower charge rate. I'm leaning towards the old mechanical regular as the culprit for the inconsistent output but would like to upgrade just one component at a time to see.
Yes 5twins, I agree with only changing out one component at a time. Put a few miles on after just changing one thing, and see how it goes.
If the voltage is not consistant, would point towards the mechanical regulator.
The goal is to get 14.0 to 14.3 volts, whenever the rpms are over 2000.
If the voltage is not consistant, would point towards the mechanical regulator.
The goal is to get 14.0 to 14.3 volts, whenever the rpms are over 2000.
XSNate
XS650 Addict
What's the story on the nylon washers? I have a 79. Do I need to change?
I see it says 80-84 so I think I am ok. Must be something different in the circuit?
I see it says 80-84 so I think I am ok. Must be something different in the circuit?
pamcopete
Ride.Enjoy.Life is Simple
The voltage from the regulator to the rotor is not a steady voltage unless the load is at the full capacity of the alternator. During normal operation, the voltage from the regulator to the rotor winding is constantly turning on and off, so what you are seeing is the average voltage between 12 Volts and zero minus any losses incurred in the contacts of the mechanical regulator or the transistor in a solid state regulator. The transistor, as an example, drops about 1.2 Volts when it is on.
If you are looking at the output from the solid state regulator of a later model, then that is not a voltage to begin with. The rotor gets its 12 Volts directly from the brown wire and the regulator provides a switched ground, so you are looking at the voltage from the other brush and a switched ground, so again, you are reading the average of those two.
WELDFAN
XS650 Enthusiast
i have a 79 with the electric start removed and converted to a non points system. im gunna re check connections, replace my fuse, and probly re run my ground with a bit larger gauge wire n see what i get. heres the lil pain in my arss...but guess when i go to build my triumph ill wish it was a xs
If you have a 1970 t0 1979 alternator, and use rectifier/regulator that is designed for 70 to 79, then nylon screws not required.
Nylon screws only needed, if you want to use a 1980 to 83 rectifier/regulator with 1970 to1979 alternator.
On the 70-79 bikes the regulator is before the rotor and controls the power to the rotor.
On the 80 up bikes the regulator is after the rotor and controls the ground.
That's the difference.
Leo
On the 80 up bikes the regulator is after the rotor and controls the ground.
That's the difference.
Leo
WELDFAN
XS650 Enthusiast
went thru all the connections, replaced the fuse, ran a new ground and she seems to be hitting the mark. im still going to keep an eye on it the next few days due to the fact i had it seem fine a few time to only have a dead battery days latter..and of course suttin lil n stupid had to happen on my victory ride..flippin gas cap popped off and despite two passes of looking for it no luck but tomorrow ill look again when its light out. thank you all for your help
I think with the vr115 regulator you don't need to change the screws on the points at the stator. Build a rectifier as per the link i posted, real easy and cheap. 2o 2 single phase or 1 3 phase rectifier as per the link.
WELDFAN, would help with less confusion on the answers posted if you started your own thread. who are the answers for you or the thread maker?
motomanmort
XS650 Member
How can I test my vr115 regulator?
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