Any ideas as to how to increase the power to my headlight w/o switching from positive to neg ground (which is needed to switch to a HID system)? I'm tired of running with my dip beam 'oil lamp', and Washington state refuses to install road braile for Norton riders.
Amperes and headlights - am I imagining a problem?
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concours
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Plug and play for peanuts, http://www.ebay.com/itm/TRIUMPH-NORTON- ... 1107144708
DogT said:
re; When I do turn on the ignition and switch on the headlamp, I get more discharge amps on the meter in low beam than high beam????
Generally because on low beam you switch on a set of alternators coils and on high beam you switch on yet another set of coils.
You have just hit the nail on the head as to why the motor industry stopped fitting amp meters. They were generally fine on the old type 6/12 volt direct current generators but when they went over to alternators they became confusing to most of the general public at large, this is not helped by the originally fitted cheap ammeters that are now 30 odd years old, and maybe a bit clapped out, on most 1970-80s Norton’s.
Every time you switch on your headlight with the engine running (if it is working normally) another set of generator coils are activated, and deactivated when you switch them off, together with the rise and fall of the speed that the engine runs – I gave up relying on those cheap ammeters fitted to Norton’s as a means of reading the output with any sort of accurately.
The most accurate way of measuring generator output s to obtain a digital voltmeter, and at least one a month to observe any faults as a preventive measure, connect the voltmeter across the battery terminals and observe the reading; when working normally it reads around 12.5 volts on tick-over rising to 14.3 to 14.7 volts when the engine running at a constant speed between 2-3000 revs, (or higher- and I stress constant speed) whatever position the headlight switch is.
Note; do not use horn or indicators when doing this as it will only confuse you.
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Bernhard said:
That certainly does not apply to any Commando, or any other British bike that had a two wire alternator as all coils work simultaneously, all the output is fed to the rectifier, and excess output controlled by the regulator (Zener).
With the crude pre-Zener charge controlled 6V Lucas system that I think you are referring to, four out of the six alternator coils usually powered the headlamp via the headlamp switch, and the other two coils fed the charging system.
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concours said:
I'm using a 55/60W H4 bulb in a Bosch H4 reflector and the stock system keeps the battery charged OK. Have not added relays yet but am using a "plus" bulb that is noticeably brighter than a standard H4....the extra brightness is at the expense of reduced life but given the low average voltage of a Commando compared to a modern vehicle life should be reasonable, have been running mine for two years or so.
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Your ammeter is reading what is being delivered to the system with the alternator wired the way you have it. The problem with the early Commando wiring harness featuring an ammeter is, the current travels from the battery up to the front of the bike to the ammeter, then back to the battery area and the ign switch, then forward to the headlight switch again before it's done any work. I suggest you bin the ammeter and remove two lengths of wire feeding it. What you are really interested in is the system voltage. There are some gucci LED voltage indicators available on ebay for about £10 (search Gammatronix). You will easily loose half to one volt between the battery and the headlight with the current going from Batt to ammeter to ign switch to headlight switch to dip switch and finally to the headlight bulb. Well worth fitting two mini relays in the headlight, one for dip and one for main, and run two fat wires from the battery to the headlight via the relays. The relays are switched by the original 2 wires from the dip switch. Result is brilliant lights.
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Bernhard said:
No, that wouldn't be correct.
Bernhard said:
I suggest you read through the charging section in the manual and study the wiring diagrams.: http://britmoto.com/manuals/Manuals/750_man.pdf
Bernhard said:
By the late mid-late 60's many British bikes had 12V electrical systems, these usually had a three wire (RM19 etc.) single phase alternator with two stator output wires (Green/Black & Green.Yellow) connected ahead of the rectifier to give 12V operation, however, the majority of Commandos had the 120W RM21 two wire stator, except for the 850 JPN and 850 MkIII models that had a higher output (180W) two wire RM23 alternator
http://www.gabma.us/elec/6Vto12V.pdf
At what rpm do the rm21 and rm23 produce their rated output? I tried running a heated vest (40watts) , lights (55 watts total) plus boyer analog ignition with the rm 21. This was too much load for the alternator at normal road speeds, up to seventy mph. The ammeter showed about two amps discharge at best, and even a thirty minute ride had he voltage down from 12.6 at start to 11.8 at finish. I have since fitted one of Paul Goffs neat little low draw halogen pilot bulbs. The rm 21 can run this light along with the heated vest, but it is a daytime only setup.
The rm23 on the mk3 (also analog boyer ignition) seems to handle the full lighting and heated vest load OK, battery voltage is at 12.5 after a two hour ride.
Glen
The rm23 on the mk3 (also analog boyer ignition) seems to handle the full lighting and heated vest load OK, battery voltage is at 12.5 after a two hour ride.
Glen
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worntorn said:
Here's the Mistral/Lucas output comparison graph for the RM21 and three phase RM24: http://atlanticgreen.com/images/lucasrm24.jpg
I can't recall ever seeing anything similar for the RM23.
Finally. Putting in halogen bulbs and high output alternators but still counting on decrepit connections and switch gear that are exposed to the elements is wishful thinking.concours said:
I like having an ammeter. A voltmeter only tells you how far the horse has gone after it's left the barn. An ammeter tells you what's happening in real time. Some interesting reading.
http://www.tonyfoale.com/Articles/Ignition/Sidebar.htm
http://www.nortonownersclub.org/support ... alternator
Do not forget figures for RM21 and RM23 were given for a brand new alternator. a 40 years old permanent magnet is not the same as a new one, gaps between stator and rotor could be sub-optimize . On the other hand a solid state rectifier could save you a few watts.
Anyway RM23 output of 180 W is at 5000 rpm , with 140W at 3000 rpm.
Anyway RM23 output of 180 W is at 5000 rpm , with 140W at 3000 rpm.
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