Regulator question

On a job at major insurance company computer data center, big UPS and Battery room, reluctant data center manager would not replace the battery room, " if your lucky the room will not leak acid all over the data centre suspended room floor, or perhaps even not catch fire in the process..." Before i arrived back at the office, new order was on my managers desk for the battery room. Matter of finding the right words for the data center manager to grasp, the sales team had no luck with a new battery room sale... i did... the manager for me was well impressed, $45K order in late 80's.... if your lucky your Laverda will not burn down to the ground over a $10 bridge rectifier.... FWIW been on a bike when it catches fire while riding, ton of fun if you like being scared..... HTH j.
 
In the thread I forgot to post a link to, BTW I also have had a bike catch fire. VERY VERY hard to put out once they're going. I would say without a huge proper type fire extinguisher you have no chance. What the gauge had in my case helped with was overcharging, the rectifier was not taking away the excess change. It just helps to warn you about future issues, way better than a light.

Odd Charging Question

I had a volt meter fitted to my 3c,my bike has a full Redax 3 phase charging system, a couple of weeks back and had an odd thing happen today. Usually it shows 14.5 volts at anything above 2500 rpms. The first ride with the volt meter fitted started cold and a solid drizzle so in bad weather I...
laverdaforum.com laverdaforum.com
 
tribonnie said:
will keep an eye on temperature of rectifier and put on a temporary charging light
Click to expand...

Installing a charging light on a Laverda isn't a simple thing. A charging light is normally connected between the D+ terminal on the voltage regulator and the switched 12V from the ignition switch. But your bike doesn't have a voltage regulator and there's no D+ connection on the rectifier.

A cheapo digital voltmeter is a much easier option for monitoring the charging system. I have one on my Jota (photo below).

The eagle-eyed will note that there also appears to be a glowing "GEN" light, which indeed there is. It's on a little volt sensing circuit that's supposed to switch the light off when the voltage exceeds a pre-set value. It worked for a couple of months, but then failed and now the light stays on all the time. As you can see, the engine is at 2000rpm, the voltage is over 14V and the bloody GEN light is still on. One of these days I'll do something about it.


Voltmeter.jpg
 
never mind the volts...whats going on with the ( elaborate ) clutch and brake lever actuators?? Is the gen light driven by one of my project pcb voltage monitor items?? If so the fix will be not too difficult, should it be an iis monitor...hth j.
 
Hi John.

They're not clutch and brake levers, they're Tarozzi adjustable clip-on handlebars. I only put them on temporarily so I could get the fork caps out and back in several times while setting up a pair of gold valve emulators. The alloy parts you can see are clamps for the handlebar tubes. I finished setting up the valves but I haven't got around to putting the Jota bars and original headlight ears back on. It's only been about 10 years though. No point rushing into these things.

I was reluctant to identify it on a public forum, but since you asked ... Yes, the gen light driver is one of yours.
I've been meaning to cut the heat shrink off and see what's in there. Maybe a trim-pot? But again, it's something I've not got around to yet. I've been too busy thinking about putting the handlebars back on :)
 
Buggered if I know Vince. It was all too long ago and I didn't keep notes. I just set the sag so it was somewhere in the ballpark then tweaked the little springs in the valves until it felt OK.
 
Many countries have compulsory lights on now. I reckon that with that riding you would be ok even with them on. I am with you regarding indicators. I wish more cars used them properly. In Oz the cops were pretty strict on it, good I reckon.
 
John,

You have a good memory. It has been so many years since I have seen a 180 with the factory alternator, I forgot about the bucking regulator coil. As for modern regulators, I use Shindegen FET ones mostly from Yamaha's. They are rated at 30 amps continuous and can be had from the breakers for $25. They also don't even get warm at full alternator output. I also have some modern Shindegen series regulators which I have not tried yet.

The Electrex regulator I am using with the ignition you sent me 30 years ago, still works fine.

Bruce
 
Hello Bruce, well done you on the FET RR option, the one or two i tried at the time ( 15+ years ago ), had some compatibility issues, just reverted to SH530 as there were thousands in recycler yards. Given the FET can control fully the phase operation of alternator coils, single double oem or poly phase aftermarket, yields best efficiency in charging battery and maintaining safe upper system voltage control. There were some with "gen" light facility, though i never saw one in the real. Glad to read the pensioner grade RR is working, we pensioners do work, just not so quick as once, grin. j.
 
Hello Cam, of designs that do not work or parts that fail, am the owner, in public is not a problem.... wry smile. One of the issues with vertically mounted incandescent lamps is inrush current, over the actual operating lamp wattage. Additionally if the filament breaks and drops down onto the internal incoming leads it all but puts a short on the driver transistor, taking it out or the driver goes short circuit, seems yours is a shorted driver transistor, inrush the issue. Not sure if NPN or PNP driver was used in the design, have to search my old drives here for a schematic, in any case, you can replace the driver, with appropriate device, or even use a FET, or send it back to me, for repair. Easy either way. FWIW the gen light board on my 79 Jota with Kwaka ZX9 pod still works, even has that "soft glow" effect as the battery settles down on idle. Fixed voltage sense circuit, no pots for adjustment.... put this up for help to others, take it to pm's as required there Cam....j.
 
It's OK John. I can live without a working GEN light. I actually like having the voltmeter now, even though it looks a bit crappy stuck on the instrument bracket with double sided tape. I'd miss it if it was gone. It's the first thing I look at when I turn the key. I check that there's adequate voltage in the battery before hitting the starter. I liked it so much that I bought a few more for other vehicles that lacked voltmeters. I put one on my 2008 Benelli because I had some mysterious charging problem. You can get versions that plug into the cigarette lighter socket in a car.

On a similar topic, I was working on a mate's bike yesterday that's a hybrid with a BMW engine and wiring harness in a non-Beemer frame. It was evidently put together by someone who didn't know much about vehicle wiring (not that I know a great deal) because some circuits were incorrectly connected and not working at all.

It has an alternator with a field coil (as opposed to permanent magnet) so it has a VR (voltage regulator) separate from the rectifier to control the field current, and a simple circuit for a charge light. But it was wired all wrongly so nothing was working. I put that right, but in the process I found that the charge light circuit went via the starter relay. This may not come as a surprise to BMW owners, but I'd not seen it before and it was a bit of a mystery until I did some research.

It has an interesting starter relay with a little transistor circuit that prevents the starter engaging while the engine is running. It uses the charge light circuit (D+) to determine whether the engine is running, and only allows the starter relay to engage if there's zero volts at the D+ terminal of the VR. I reckon Ron could have used one of those relays rather than wiring his starter circuit via the neutral light. :)

BTW, that start lock-out feature is a simple little circuit that could be made for a few bucks and incorporated into the wiring for any starter relay, but you need a D+ connection so it'll only work on vehicles with a VR that controls a field coil. I think the 750 SF bikes are wired that way. I can provide the circuit details if anyone is interested.

Start lock-out is more of an issue on bikes with a car-type ring gear and Bendix pinion starting system like BMWs and Guzzis because it can damage things if the starter engages while running. It not really necessary on bikes with sprag clutch starters, but if it gives you peace of mind (as it did Ron) who am I to argue?
 
While on the subject of regulators, both my 1200TS and RGS had Nippon Denso regulators. These are to be avoided especially if running a Moto Witt ignition. Both of them put out 15.2 volts which will cause the Moto Witt to shut itself off usually when it is very dark and cold and miles from home! If you shut the key off and wait a few seconds it will start back up for some miles before failing again.

I have three IIS ignitions and they don't care about over voltage but my RGS has a Moto Witt and it does. All now have Shindegen FET regulators except for the 3CL which has an Electrex. I have a Shindegen for it to but the Electrex works fine.

I have both Shindengen series SCR and shunt FET regulators that I will try on the 3CL. Need to do some research to see what I think is better. As I have been retired from the electrical engineering business for seven years, I have forgotten many things.

Bruce
 
1200ts said:
While on the subject of regulators, both my 1200TS and RGS had Nippon Denso regulators. These are to be avoided especially if running a Moto Witt ignition. Both of them put out 15.2 volts
Click to expand...
This may have been your experience but two points :
The OE reg/rect was not designed to charge at 15.2v. The effect of age on these devices means that their output increases over the design spec. It is very wise practice to replace aging RRs with modern equivalent to assure proper operation.
The very early Moto Witt DMC is now susceptible to over voltage. Later units less so. Max design voltage is quoted as 18v
 
Rob said:
The effect of age on these devices means that their output increases over the design spec. It is very wise practice to replace aging RRs with modern equivalent to assure proper operation.
Click to expand...
I wasn't aware that they would allow overcharging as they wear out, so to speak. That makes a voltmeter a wise investment. I am glad that my Koso tacho/speedo instrument has a voltmeter.
 
Thanks for all the replies, getting to the point where I haven’t a clue what you are talking about
But ……. the dilemma I have now is do I buy a Reg/Rec or a fire extinguisher
 
Agree with you Hamish. 😂 Love the photo!
I greatly respect John Wilson's expertise but have never heard of a fire on an early triple using the OE Bosch rectifier. Generally if a diode fails in this application, it fails open circuit and the battery receives no/reduced charge. If circumstances prevailed that caused it to fail short circuit (e.g. a large reverse voltage from the planet Zog..'cos it certainly isn't coming from the puny alternator) then the large current flowing from the battery could be stopped by fitting a 15A inline fuse in the red wire(s) from the rectifier to battery.
 
Read only if background information is of use....bit of a ramble, wry smile here.

Hello Rob, some points for clarity, mentioned the old style rectifier issues in context of the era, have one here in the bin of shame somewhere, it shows the type of high temperature failure indicated. My description was "fire hazard" and that remains the case. Not that we had a Laverda catch fire, the warning was sufficient to act and replace. Of diodes ( any junction type semiconductor ) have various modes of failures. A least understood is reverse bias leakage, a notable design issue for switching power supplies. Power dissipation or Pd is of most interest, given the area of the semi junction can be less than a square mm, any power dissipation is concentrated ( indeed, generated ) across that die area, spot overheating can produce extreme temperature and ongoing thermal issues with encapsulation materials, the old rectifier in question from memory was petroleum based and did exhibit flame potential.

Of fuses, that is also complicated, in the case you mention, 15A fuse, when does it clear? Not at 14.9A, then suddenly clears at 15Amps? Ostensibly a fuse is a fault current limiter in operation, to specify fuse operation you will require the I squared t information. Also type of construction, from open fuse wire to the silver/sand fuses have replaced in expensive corporate equipment, the subject was so complex i needed the assistance of fuse manufacture engineers to have a proper grasp of what a fuse does and operates. UK engineers funny enough were of most help.

Your observations are correct overall, the details are where outcomes are not so obvious. The fault current figure for a bike battery may well be in the order of many Kamps perhaps a momentary 1000A, a failing diode would perhaps try to dissipate that Pd, go open circuit likely, or fuse the PN junction and go short, seen many modes of failure, and post failure analysis of the die where possible, yields what actually was the cause of failure. Semiconductor junctions have various failure states, not open or short, can be stages in between, know this is not directly on topic, out there all the same. j
 
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