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Rebuilt solid state regulator and now ammeter is pegging at +30??


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Ok so my ammeter was "bit bouncy" and figured it couldn't hurt to do the solid state switch. So I got back and installed today. At idle, it just +1-5, and as soon as put the lights one, it goes (-) - so I figure great. Problem is if I even feather the gas, it pegs on the meter at +30??? IS this an issue I need to be concerned about? I switched the car off for fear of frying my system?? Suggestions of attack?

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Too low. Should be 14.8V. So the charging system is working full blast to compensate. Once the battery is charged, it should go back to a slightly positive current.

 

Badfrog

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Actually, a fully charged battery will be reading 12.6V (with nothing connected) NOT 14.8V.

 

14.8V is the voltage you will see with the engine running around 2000RPM charging a LOW battery. When charged, it will be reading between 13.6 and 14.4.

 

Cheers

 

Tony

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If this is knocks 30A into the battery for any length of time then it will overheat and have a short life.

 

If these semi-conductor things can't do any better than this then you should stay with the original.

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Tony,

 

That's what F1loco referred to: voltage delivery with engine running. At least that's what I understood by "state of charge".

I agree that the isolated passive battery delivers around 12,3-12.6 V. My 14.8 V relates to the engine running high enough for full current production, as you said. When the battery is a bit low, this is associated with 30 amp out current. Of course it should only last for a moment (expressed in minutes, not hours).

China-built electronic devices are not checked at the end of the production line. It is the buyer that does the checking. So it could be a fautly regulator if the 30 amps last forever. Action: either another one or the real part as Alan suggested.

 

Badrog

Edited by Badfrog
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I agree it could a faulty regulator JF, it could also be a duff battery (shorted cell) as that would also allow full current to flow. It should be interesting to see the final diagnosis. Bet you a pint it's the battery... :D

 

Cheers

 

Tony

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Tony,

 

That's interesting. I understand a shorted battery would not accumulate current, hence the lengthy 30 Amps output, but how could a shorted battery read 12.3V and allow current flow ? Shouldn't it block the process?

I'm a zero in electrics so bear with me.

 

Badfrog

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This a a regulator! It does a number of jobs. But one thing is that its supposed to limit the charging current.

 

Ideally you would not be putting more than 8-10A into the battery even it was flat or shorted. The old mechanical ones on TRs only have two-coils and and not great at stopping excess charging.

 

There is a later three-coil variant which is better at this.

 

So if your semiconductor one is worse than the two-coil then.. you work it out!

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China-built electronic devices are not checked at the end of the production line. It is the buyer that does the checking.

 

 

Your generalized statement is absurd! That said we don't even know where he bought this SS regulator. If it is the Bob Jeffers design you can be sure it was assembled and tested in New Hampshire, USA. If you read my recent posts regarding a dynamo failure, you will note that I was too quick to point a finger at the regulator as the source of trouble. In fact it was a bad dynamo all along. Getting back to the regulator, it is important to identify the dynamo and its maximum current rating. I made a mistake and had identified mine as a LUCAS C40 when in fact its a C39PV2. This resulted in a current limit setting (made at the factory) approx. 16 percent too high. Depending on one's driving habits and use of electricals, etc, this can kill a dynamo very quickly. Bob Jeffers was quick to point this out and we got the setting sorted.

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Too low. Should be 14.8V. So the charging system is working full blast to compensate. Once the battery is charged, it should go back to a slightly positive current.

 

Badfrog

No, that's not correct. All modern 12 volt batteries, regardless of design, have a cell voltage of just over 2 volts. To be more precise:

 

  • Open-circuit (quiescent) at full charge: 2.1V 6 x 2.1 = 12.6 volts
  • Open-circuit at full discharge: 1.95V 6 x 1.95 = 11.7 volts
  • Loaded at full discharge: 1.75V 6 x 1.75 = 10.5 volts

You may be thinking of the typical alternator output when charging a discharged battery.

 

For example:

  • Typical (daily) charging: 2.37V to 2.4V which gives you 6 x 2,4 = 14.4 volts
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Ok so my ammeter was "bit bouncy" and figured it couldn't hurt to do the solid state switch. So I got back and installed today. At idle, it just +1-5, and as soon as put the lights one, it goes (-) - so I figure great. Problem is if I even feather the gas, it pegs on the meter at +30??? IS this an issue I need to be concerned about? I switched the car off for fear of frying my system?? Suggestions of attack?

Where did you buy your regulator? Read my reply to badfrog. its important to have the current limit set properly or you will destroy your dynamo. As others have stated, the charge rate you describe indicates a battery that is discharged. One thing you can try is to have the battery checked and if necessary charged and reinstall. If that doesn't work, then I suspect the regulator needs to be adjusted or replaced.

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Sorry, it's not absurd but plain truth.

This was the answer I got from a big manufacturer of laboratory hardware when complaining about the failure of a brand new pHmeter. I expressed surprise about this fact when talking with another sales rep from another firm and got the same answer: it's cheaper to refund or repair without question than to check every single circuit of component coming from the big component makers.

The pHmeter was german and the other sales rep was working for a US company. A world-wide problem obviously. I was talking about chinese mass production, not US small scale electronic companies.

Finally, such checking at the production is commendable, but it does not guarantee life duration of the material.

I usually only talk about what I know. Please remember this.

 

Badfrog

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I usually only talk about what I know. Please remember this.

 

 

It was your generalization that attracted my attention. Regardless of what you have experienced, many Chinese built devices are completely tested during production. Having prepared production testing specifications and quality control procedures as well as automated production line testing, I can assure you that your generalizations are not appropriate.

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You may be thinking of the typical alternator output when charging a discharged battery.

For example: Typical (daily) charging: 2.37V to 2.4V which gives you 6 x 2,4 = 14.4 volts

 

Yes, and 14.4 or 14.8 V is function of the aging state of the cheapo analyzer and me looking at the small dial with not so accurate eyes.

So we agree on this: a good battery is 12.6V on its own and the full charging in the complete system is the vicinity of 14.5V.

 

Then, can you elaborate on how the 16% variation in output can be detrimental? This is interesting and as I said, either I know or not and when I don't know, I ask.

 

Badfrog

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Then, can you elaborate on how the 16% variation in output can be detrimental? This is interesting and as I said, either I know or not and when I don't know, I ask.

 

Badfrog

Sure! In this particular case a few assumptions are necessary. From the perspective of the battery, if the battery is already compromised such as in the case of a bad cell, further forcing a high charge current could buckle the plates, over-heat the electrolyte and possibly cause an explosion. Not good at all. From the perspective of the dynamo, if the current limit is set too high, the dynamo would try to supply current beyond its design limit. For example, according to LUCAS literature , Triumph selected the C39 design based on an average demand not exceeding 16 amps. This dynamo has a maximum output of 19 amps. Back in the days when our cars were produced, this dynamo was adequate. Things are different now and with modern enhancements its easy to exceed 19 amps. However during my recent trip to North Carolina, I figure I was running somewhere near 20 amps continuous, due to the use of main beams, heater/fan, windscreen wiper, etc. The current limit had been incorrectly set (my error) at 22 amps. This allowed my dynamo to run in overload most of the time. The current limit setting should have been 19 amps. If electrical loads required more than 19 amps, the battery would eventually run down to a point requiring an external charge.

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Tony,

 

That's interesting. I understand a shorted battery would not accumulate current, hence the lengthy 30 Amps output, but how could a shorted battery read 12.3V and allow current flow ? Shouldn't it block the process?

I'm a zero in electrics so bear with me.

 

Badfrog

 

Faulty batteries can cause some weird, inexplicable things to happen JF....honest... :D I still bet the pint.

 

Tony (lives in OZ and is now used to weird things happening(

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Well... battery is full charged, but ran it today to take some readings...

 

At rest, it's a whopping 12.7

At idle, it is a whopping 12.7

At about 2K on the tach, it's 13.8

If I Rev it, the battery readings go as high as 14.2, but stay around 13.8 for the most part.

 

AND...still pegs at 30amps with any kind of throttle and if I hold it for a few seconds, needle sticks. Upon tapping the glass to the gauge it goes back down.

 

So is it the regulator or the dynamo possibly?

 

Any quick test to tell??

Edited by F1loco
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Where did you buy your regulator? Read my reply to badfrog. its important to have the current limit set properly or you will destroy your dynamo. As others have stated, the charge rate you describe indicates a battery that is discharged. One thing you can try is to have the battery checked and if necessary charged and reinstall. If that doesn't work, then I suspect the regulator needs to be adjusted or replaced.

Regulator was through a guy here in the states that is well known for building the boards for converting the coil set up.

 

He inquired as what "dynamo" I had and to be honest, there was not a single case stamping I could find on it for him. We anticipated it was a replacement type with this figures:

 

 

The original Lucas dynamo fitted was model C40-1, part number 22700.

Details from the Workshop Manual are as follows :

Model : C40 - 1

Type : Two brush, two pole, compensated voltage control

Rotation : Clockwise

Field resistance : 6 ohms approximately

Maximum output at 13.5 volts : 22 amperes at 2050 - 2250 r.p.m. (connected to a load of 0.61 ohms).

Brush tension : 22 - 25 ozs. (0.62 - 0.71 Kgs).

Minimum brush length : 11/32" (9mm)

 

 

Did you have similar problems not knowing your dynamo wasn't the Lucas specs? I just tried to take a reading at the regulator from the brown/yellow and brown/blue coming off the dynamo and was getting MV readings, not even a V? But when I rev'd it, the battery readings would go from 12.7 to 14.2?

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Tony,

 

Do you infer chamanism at work, with funny old men pointing twigs at your battery while mumbling?

 

Badfrog, too much Aussie movies, obviously ...

Edited by Badfrog
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I am looking at wiring diagram I found and beginning to wonder if the previous owner had a clue about wiring...looks like a few of the wires are crossed on the regulator. Will straighten them up when I get home and see if that helps things out. Question, on a positive earth ground system, the wire coming from the distributor to the coil is currently connected to the (+) side of the coil? Beginning to wonder if it should be the (-) side of the coil and the (+) going to the ignition switch? Does this sound correct? I'm guessing that may help with better spark as the current will be pushed better to the plugs??

 

What a mess...

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