rectifier/regulator

[Drummie]

Hi All, i'm looking to replace the existing zener and rectifier (knackered) with a rectifier/regulator unit. It's a 66 royal star and I am wondering with the stator's 3 wires, is it a single or 3 phase. Coming from the stator, 2 of the wires are connected. The bike has a Boyer electronic ignition and is 12v. Any advice from anyone who has dealt with this would be very much appreciated. Also any recommendations of which unit to buy or parts dealers worth calling. thanks in advance Drummie.

[Caulky]

Your bike is single phase, if it was 3-phase it would have a 3-phase rectifier, utilising each of the three alternator wires seperately.
The reason for connecting two of the alternator wires together is to get the maximum power from the alternator.
There are many rect/reg units available, all of which are superior to the original set-up, if located on metal in an airstream for cooling.
Personally I use the Sparx SPX001, but 5000 Ohm loaded plugs or plug-caps must be used.
http://www.tri-corengland.com/acatalog/Regulator_Rectifiers.html

[Dean Southall]

I've used a  DVR  on all my BSA rebuilds (bikes and car). Fit and forget and been running them for years.

The owner is a beeza man

http://dynamoregulators.com/index.php

[ChrisG]

Sadly Dynamo Regulators don't do products for Alternators, but are great for Dynamos.
Re alternators, I fitted a Wassell 3 phase product to my OIF Thunderbolt  (it has a 3 phase alternator) and its still going strong after 14 yrs so definitely fit and forget.
However the early ones like mine do have a minimal leakage from the battery so if you leave it connected far a number of weeks without use, it will drain the battery. Not a problem on an OIF, I just lift the seat and take out the fuse. On the Royal Star, this would mean taking off the side cover (dreaded Oddie fasterners) every time you leave it for a few weeks, unless you extend the battery lead with the fuse to poke out in a convenient place.

[Drummie]

Thanks Guys for the advice, I'll look into buying one now. I was guessing the stator was 3 phase because it had 3 wires. Fortunately that's been cleared up before I bought the wrong one.  Is there a dealer you would recommend? Drummie

[Drummie]

Hi again, I've gone for the Sparx SPX001 regulator rectifier, as Caulky suggested. It didn't come with fitting instructions so im just checking I've got this correct. Green&Black/Green&Yellow  (wires joined together) to Yellow from reg/rec. then Green&White to other Yellow wire from reg/rec. Am I correct in thinking, as the bike is positive earth the Red wire from the reg/rec goes to earth and the Black wire goes to the ammeter in the headlight and then the ignition. Thanks Drummie

[Caulky]

http://www.tri-corengland.com/acatalog/Single_Phase_fitting_Instructions.html

[Drummie]

Thanks for getting back to me Caulky. I've been told because the bike is positive earth, I should run the RED wire to earth and the BLACK wire to ignition. just checking this as really not sure. I've noticed the wire to the battery - negative terminal has an inline fuse, and the +positive terminal wire goes to the earthing point on the old lucas rectifier. I have just looked up a lucas rec/reg on ebay and the wiring diagram shows the RED and BLACK wires reversed for positive earth bikes. This could be where my mate got his info. Do you know if the SPX001 unit is the same. Drummie.

[Caulky]

Red wires are postive (+), black negative (-). Unless *
So, for a positive earth bike (chassis/frame) the battery + red goes to the frame/earth and the red rect/reg wire.
The heatsink obviously needs to be mounted somewhere to the frame in an airflow.
The internal electronics are isolated from the heatsink, so it can be fitted to either +ve or -ve earth bikes.

*Now, some people convert their bike to negative earth, why I don't know? It causes confusion when the bike is sold on to innocent buyers.
If these people are using the the original wiring loom, it means that the wiring colours are now wrong. (red & black reversed polarity and the rectifier/coil connections are changed to suit).
Later Triumph T140's were negative earth and the wiring harness is colour coded to reflect this.
Your bike appears to be standard positive earth, negative feed is fused. Wire your bike as standard, you can remove the points arc capacitors and the old rectifier.

*Again, to add to the confusion to unsuspecting bikers, some people change the wiring, so that both power leads from the battery may be fused, or either singly.
This subject has been discussed to death in various forums.
I suggest you stick to the original wiring diagram for your bike, shown in the workshop manual.
Don't forget to use loaded plugs or plug-caps. The plugs will have an 'R' in their part number. I prefer to use loaded plug caps because any suitable (non 'R' plugs) can be substituted...don't use both loaded plugs and caps.
Ignore Ebay.

[Drummie]

Many thanks Caulky, i'll get it fitted and see how it goes. hopefully my charging issues will be over. thanks again Drummie.

[Drummie]

Hi all, hopefully i'm not becoming a pest as I have a couple more questions on this subject. First one is, I have positioned the rectifier regulator on a bracket I made up. While it is bolted to the original mounting point for the old lucas rectifier (under the seat) with the use of the bracket it sits lower and closer to the shock. My thinking is the air flow the rear wheel will produce may be enough to cool the unit. Please correct me if this is not the case. My second question is, having fitted the SPX001 rec/reg and the bike also having a boyer mk3 electronic ignition, can I use the 12v coils already fitted? I have read other posts where they seem to have been swapped for two 6v coils. Thanks in advance Drummie.

[ChrisG]

Location regarding air-flow is not super critical as long as it in the open i.e. not inside a toolbox for instance. On my A65 OIF Thunderbolt I fitted mine to the underside of the Battery Carrier which places it between the airboxes so it gets a whiff as the air intake passes by but no fresh air from the speed of travel. I have never had any problems in the last 14 yrs, (apart from the slight voltage drain when not used, as mentioned in previous post).
Regarding the Boyer ign, they did advise some years ago to use 6V coils as earlier systems didnt work with 12V coils if the voltage dropped below around 6V I think. However, my Thunderbolt has a Mk3 Boyer and the original Lucas 12V coils, and I've never had any problems during the same period of ownership. Maybe I've been lucky???
Chris

[Drummie]

Hi Chris, thanks for the reply. The bike has been running fine with the 12v coils and boyer ignition, although battery wasn't charging properly ie would run all day if I didn't use the lights. What concerns me is having fitted the new sparx rec/reg to try and eliminate the charging issue, could it interfere with the coils or boyer, or am I barking up the wrong tree? electrics is far from a strong point with me. Drummie.

[Caulky]

An explanation.
With the old points system, each 12V coil charges with energy every other cycle of the crank on its compression stroke. (left/right/left/right/etc) four stroke engine,
So each coil will have 12V across it before its point opens and the plug fires. Each 12V coil primary has a resistance of around 4 Ohms, giving a DC current of I=V/R, I = 12/4, i.e. current I = 3 Amps.
It is the 'rate of change of current' which governs the primary voltage. Although it appears to be instantaneous when the points open, it isn't because of the nature of the release of the magnetic energy is a discharge curve (hysteresis), and the internal resistance. But it is very quick.
The primary coil produces a back EMF (opposite polarity voltage spike/pulse) which opposes the applied 12V DC voltage of around 100V,  which is transformed by the huge number of turns in the secondary into thousands of Volts at the plug gap. This voltage is high enough to ionise the compressed fuel/air mixture which significantly lowers the resistance, and an arc (spark) ignites the mixture at its timing point.

With an electronic ignition, the above still happens BUT, the coils are in series, both fire at the same time.
So here, we have 12V across two coils. *If they are 12V coils the available current is halved because the resistance is doubled, 8 Ohms, hence the available energy is also halved.
This is why 6V coils are recommended, because their primary resistance is around 2 Ohms, giving a total resistance similar to a single 12V coil.
The reg/rect unit prevents overvoltage to about 15V, this prevents the battery from overheating and the electrolyte boiling.
Although the 12V coils usually work, there is a snag if the battery is not in good condition, fully charged.
A bad battery may cause misfires, if the voltage is too low, a fully charged battery has a voltage of 12.6V. More when running (~14V).
Radiated and conducted voltages may affect the electronic components in the rect/reg, which is why loaded plugs or plug caps are recommended.
Especially from the spark plug, because it a mixture of various spikes at various frequencies, this load attenuates the spikes to a reasonable level.
The primary voltage is prevented from going back to the E.I. unit by blocking diodes/filters.

If you have charging problems, they are caused by 1) bad battery 2) alternator not coping with the load current  3) poor wiring/connectors.
Usually, the battery itself is the source. If any of the cells are damaged, it will hog current, which ought to power the normal electrics.
Simple test, ignition on, main beam on, motor not running.
From Sparx "a good battery should sustain 12 volts for 10 minutes". If the lights dim greatly within this time limit, get a new (tested) battery.
   

[ChrisG]

Hi Caulky,
At last, a proper explanation! Brilliant and many thanks for this. Can I put your writings in The Star as a Tech Article?
Chris