750 Bosch Voltage Regulator adjustment

Used to night drive with 2 x 60W halogens when on high beam (H4 headlight and Cibie driving light). Always stayed charged. They produce sufficient wattage - rated at least 150W at cruising speed (from memory) but recall hearing a test showing higher than that. 65W wouldn't get you far, Ron!!
 
That Bosch Dynamo was a heavy bastard and barely delivered. I should have replaced it with an alternator, say from a Suzuki 3 cyl car, that delivers 3 x's the out put and weighed in less then 1/2 - but I never did and lived with the consequences ;o)
 
I used my heated grips during a long morning ride in drizzling rain a couple of weeks back I was also using the 90 watt low beam as the light conditions were very dull and flat. I was having trouble getting the grips to come on as they automatically detect if the voltage is below 12 volts and wont turn on, I did a quick check after fitting that voltage gauge we all were talking about a month back and It was still 12.5 and slightly higher at 3 to 4000 rpms with the grips and low beam turned on, so it still kept the battery up but it was lower that I expected.There was an issue during that wet ride where one phase of the 3 phases wasn't actively connected to the system with a burned pin, now fixed. These gauges are just so handy to catch problems before they strand you road side with a flat battery. It will be interesting to see what voltage it shows on the next long day ride.
 
Allways che

Forgot the orange SF(72) and the Buell M2 in our group.
Mathias found a picture he had made.

Thomas aus LAU
Fond memories. We arrived at our lodging in Monte di Malo at around midnight that day. The Atlas had no brakes, pistons were sticking. We found somewhere to eat at 22 hrs on the Altipiano di Asiago. Corinne decided that she would lead on her Triumph with GPS instead of getting lost.

One of the passes we had wanted to take was closed, so there was a detour. Detour was about 200 km.

Paul
 
Cam, I had the wire between the two sets of field windings broken on mine once, quick solder fix. Have you/he had a look inside the genny?
No, I didn't even look at the generator. The charging issue had been (temporarily) sorted by the time I got there yesterday. He'd borrowed a genny from a local SF owner that he'll post back to Tas when he gets home. I spent a couple of hours chasing an ignition issue instead. Eventually got that fixed, so he can now continue his trip around Tassie and back home to Queensland.

Thanks for the help guys.

One other question: Is there anyone who re-winds generators somewhere in Australia? There used to be an old guy here in Tassie who did them but he's retired now.
 
There is a place in South Oz called Betta Bikes, they specialise in doing big light upgrades used in the 24hr trials race they do there. Plus fixing unfixable older Husky EIs and alternators. I sent my failed Husky bits to about 3 or 4 specialist Bike Auto sparky's including Small Coil Rewinds in Vic but the South Oz blike is the best I found.
 
SF2 now over 6500km. Continuing problem with overcharging. Before the rally I took the tank off, and ran the bike with the cover off the regulator. It had been charging with the headlight on at 14.7 - 14.8 volts. Low beam 55/60 H4 bulb. I tweaked the adjustment on the points gap, and I had 14.2 with the headlight on. I double checked my little voltage Meter against my Multi Meter, accurate. All went well for the first 2-300 km. Then started spiking up over 15 volts. High beam on, 60 watts, helped a little. Seems like the reg would trip out, drop to battery voltage, then charge high again, cycling like this every minute or so. Tried resetting by turning it off and on, no change.
Bought a 55/100 watt bulb in Adaminaby, fixed. Charging now at 13.8 v to 14.3, depending on speed. Not a permanent fix, that's a lot of power running around. I am going to try and locate this mythical bosch upgrade regulator, wish me to luck.
 
Marty,

Is the regulator vibration isolated, ie, mounted on the rubber strap? Or at least on a couple of grommets? Vibes do stupid things to the contacts.

Bosch #s are 0190215028, 0190215034, 0190309018, 0190350006, 0190350007, 0190350013, 0190350055, F026T02203 for the electronic version of the original.

They retail here for around €120. I've fitted quite a few with excellent results.

piet
 
You can get an electronic voltage regulator that'll do the same job as your clunky old electro-mechanical dinosaur and be more tolerant of vibration. They cost peanuts and are reliable. At only around $10 to $15, you could buy a couple and keep one as a spare.
Some electronic VR's have a trim pot for adjusting the voltage but they cost a few more peanuts.
 
Here's the adjustable one. It's 3 pin so would be suitable for a DC generator. It's actually for an R-series BMW. Although those bikes have an alternator and rectifier, it's not a permanent magnet alternator, so the voltage control is done by switching the field coil in and out exactly the same as on your DC generator. Those BMWs were originally fitted with the same clunky Bosch VR that Laverdas had, so the electronic replacement should work just fine.

This cheapo Chinese VR has the same D+, D- and DF connections so it appears to do exactly the same thing (although not adjustable).
It might be rubbish but worth a try at that price. I've bought some dirt cheap stuff out of China that's been surprisingly good.

If you're concerned that the Chinese one can't be any good for the price, there's no reason an electronic VR should be expensive. They only have about $5 worth of electronic components in them - a couple of transistors, some resistors and diodes. Solder them together, shove 'em in a box and fill with potting epoxy. Job done.
Any factory that can't make them for under $20 is doing something wrong. Selling them for $176 is profit gouging to the max. Welcome to the free market economy where things are worth what some poor sucker is willing to pay.

Come to think of it, with a soldering iron and a circuit diagram, you could make one yourself out of parts from Jaycar. Here's a recipe I found on line. There are probably heaps of others. You might even be able to find one in kit form somewhere.
 
Aren't those BM and Guzzi alternator systems? There have been cheap electronic rec/reg available for ages, but not for DC generators. At least that is what I understood. The first DC electronic systems I came across were from Sachse.
 
Cam,

Post-1969 Beemers, starting from /5 series, all have alternators.

The replacement Bosch item may be expensive, but it is plug-n-play. I've experienced too much shit with cheap alternatives to risk another meltdown... happy to pay the premium for something I can rely on!

piet
 
Cam,

Post-1969 Beemers, starting from /5 series, all have alternators.
Yes, but voltage control is by switching of the DC field armature - same as a DC generator. So they use the same Bosch tin can type voltage controller. Basically, the only difference is that the Beemer's alternator brushes run on slip rings, whereas a DC genny has a commutator.
 
I bought a DVR4N, 12 Volt, 11 Amp for the 750 twin long ago based on chat with supplier though have not yet needed to install it, sounded like just what we need. If it works with British-electrics-equipped cars then should have no problems in the Laverda twins. It's compact and easy to hide and they claim it works with the charge light.
I have several original Bosch regulators that are still working just fine since they are simple and rugged if isolated from vibration but I'm trying to be prepared for when they decide they've had enough abuse and replacements unobtainable.
Time to install it and see how it does. I'll post results when the workshop priority list allows. If anyone has installed the DVR4N on a Breganze 750 please let us know how it works.
 
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