Regulator Woes

[Kiwi_Roy]

I have been having intermittent low battery voltage accompanied by other mysterious symptoms. All along I suspected the regulator and went as far as ordering parts to build my own (still a work in progress).

In the weekend I pulled the Ducati reg off and thought I would remove the guts so I could build my new one into the shell, also try and find out what's gone on with it.

I found one of the main diodes had come unsoldered from it's lead with obvious signs of arcing this would cut the output in half at least. Other than this obvious fault there seems to be little wrong so I soldered the diode back together and will give it another shot.

While I was about it I reverse engineered the circuit to get a better understanding of it's workings, basicly a bridge rectifier made of 2 diodes and 2 SCRs. A regulator circuit turns the SCRs on as required

 

If anyone has some old burnt out regulators around I would be interested in obtaining the case to build my prototype into. Please send me a PM

 

Roy

[raz]

I've been thinking of doing an autopsy on my old one too. Probably the exact same problem as yours have. How did you get into it, heat gun?

[luhbo]

That's an interesting thread. My regulator problems began with a "leaking" battery and two burnt headlamps in a row. Basically it's been the 2nd burnt bulb what made me measure the voltage. 17V at 4000 - and a sweating but quite new Hawker! This was last october after some days in rain and cold. A short time cure was to cook the regulator in our kitchen oven at 120°C for 2 hours.

During winter I then cut out the plastic stuff down to the PCB. The idea was more to make it easier for the internals to dry. Anyway, once remounted the regulator was completely dead. Only then, using a 10x microscope at work I found some solder points, not only one, to be looking a bit strange. One of them had become completely loose indeed, or maybe never was soldered at all. Crap.

 

Actually all is well now. I laquered the back of the pcb to keep the most water and debris away from it and so far this does an appropriate job. Nevertheless I feel this is a bit a week point at my bike. Probably international communism will strike when bicycle repair man isn't available at all.

 

Hubert

[Kiwi_Roy]

I've been thinking of doing an autopsy on my old one too. Probably the exact same problem as yours have. How did you get into it, heat gun?

Hi Raz,

No the material in mine is semi hard, I just took it out in slices with a utility knife.

Once I got some out I managed to work the rubber wire grommet out that allowed access to the under side (component side)

You have to unsolder the 3 wires to diodes and the two SCRs as they stay with the case.

I haven't quite finished the schematic, still have a couple of points to clear up.

 

Roy

[raz]

I laquered the back of the pcb to keep the most water and debris away from it and so far this does an appropriate job.

You didn't refill it with some kind of goo like there was before? I imagine 100 VAC would love some moisture around those components.

 

Maybe I should put some laquer where the leads come out of the rubber, as a preventive measure.

[raz]

No the material in mine is semi hard, I just took it out in slices with a utility knife.

Once I got some out I managed to work the rubber wire grommet out that allowed access to the under side (component side)

You have to unsolder the 3 wires to diodes and the two SCRs as they stay with the case.

This will be a fine job for next winter, and then I can sell my newer regulator as almost new. I guess my old one could be regarded more reliable than the new one, after I fix it and check all soldering.

[Kiwi_Roy]

 

During winter I then cut out the plastic stuff down to the PCB. The idea was more to make it easier for the internals to dry. Anyway, once remounted the regulator was completely dead. Only then, using a 10x microscope at work I found some solder points, not only one, to be looking a bit strange. One of them had become completely loose indeed, or maybe never was soldered at all. Crap.

 

Ah Yes, a dry solder joint, I found one on my board, either caused by vibration, not being hot enough or movement as it cooled.

I'm glad you got it working again. Hopefully mine will work also, I'll keep you posted.

Roy

[raz]

...caused by vibration...

Yet the potting is on the component side too, or isn't it?

 

Maybe one could fix the components with hot glue and fabricate a water proof bottom lid instead. All hot components are screwed to the cover, right?

[Kiwi_Roy]

Yet the potting is on the component side too, or isn't it?

 

Maybe one could fix the components with hot glue and fabricate a water proof bottom lid instead. All hot components are screwed to the cover, right?

Potting compound is everywhere

 

Once I get mine working I will fill with silicone sealant

[The Monkey]

Potting compound is everywhere

 

Once I get mine working I will fill with silicone sealant

 

Sikaflex works wonders at keeping electrics dry Roy! Has anyone hauled apart one of the Accel regulators referred to in a related post that were for the late 80's - early 90's harleys. To have to accommodate the poor quality control associated with these replacement regulators at this point in our evolution beggars belief! My last one gave up with 4 days run on it, the replacement is still in the bike but after 3 days run, I wonder at its potential life span considering my tach jumps at the end of the day when I either work the turn signals or hit high/low on the headlight. Idle just drops away to nothing- you dont need a voltmeter with these scooters, I have found the tachometer a very useful tool for indicating charge rate! @#!#$# me, I would gladly hang a working reg off the side of the bike a la panhead if it would only do its job. 7 days - 6,000km 2nd reg about to pooch! at least have an original replacement reg to put in next- (the original lasted 74000km). Keep up the news gents, it is being read with more than just a little interest. Wonder how I would do on a tour bus?

[fotoguzzi]

Are you saying "carry a spare reg on road trips"?

[luhbo]

Don't take this way. Of course a late regulator will leave you stranded, but so will do broken camshafts, gone big ends or dead ecus. Such parts just have to last - and usually they do.

 

Hubert

[raz]

Are you saying "carry a spare reg on road trips"?

 

The trick is to always, always carry a bottle of whisky. This way, no matter what breaks down, you'll be fine until picked up.

[docc]

. . . always, always. . .

[The Monkey]

Are you saying "carry a spare reg on road trips"?

 

No, I just have to at this point, will pass on info regarding the regs not to buy soon. Hubert is right, the things should last just do your homework before replacing. Raz is ever so right, although I pack Tequilla. Funny and sad- as I sat beside the road awaiting the service for which I pay to come retrieve me no less than 4 new types on their massive motorcycles paraded past without pause, then I heard the distinctive pop of a single approaching, an 250 enduro on which a feller in his 60's did stop and ask if all was well. Nice to see a human out here. The adventure does only commence when something goes awry. Cheers