Testing the Logitron regulator/rectifier

[Ventodue]

Fine, you have the necessary equipment at hand to perform a functional test of the R-R.
The figure shows the necessary arrangement of the components mentioned in my last post. The text in the figure tells what has to be done. Don't hesitate to ask any question, if you are in doubt.

Lovely, Hans. I'll put all that information somewhere safe - and hope that I never have a need for it .

Once again, thanks.

Craig

[Ventodue]

... but I now understand the r/r unit plays no role in firing up the bike. There is a red wire going from the battery directly to the ignition key switch.

I attached the wiring diagrams i made myself for reference <snip> ... a second one after the Sachse conversion.

Good stuff. For one thing, anyone who ascribes the code number "1" to the alternator gets my respect . It's all too frequently - e.g Ducati 860 factory diagram - around number 21 for reasons that escape me ...

Is a 6 Volt charger supposed to put out 9 Volt when not connected to a battery?

A good question and one to which I honestly don't know the answer . But I can quote you this:

"Set the charger to charge at 6 volts. Charging at a higher rate can damage your battery and may be dangerous."

[ducwiz]

Brilliant!! Thank you for the test circuit, that is very useful. I'll be putting that test set-up together next weekend, if my AC transformer can be used:

I have two AC transformers available, but as i just found out (sorry for the earlier misinformation) both are putting out more than 12 volt.

1) 16 Volt /~ 0,7 Amp
2) 14 Volt /~ 1 Amp

Can the excess of voltage for this test be compensated by the use of a incandescent bulb with a higher wattage?

Choose the 14 Volt/~ 1 Amp with a 12 Volt / 10 Watt bulb. I use this one:

A leftover from my youth, when it powered electric railway models.

Thank you for clearing up my misunderstanding about the function of the r/r unit. I will still test it, but i now understand the r/r unit plays no role in firing up the bike. There is a red wire going from the battery directly to the ignition key switch.

I attached the wiring diagrams i made myself for reference. Have a good laugh over it, but remember i have no education or training in electronics whatsoever! One with original Motoplat wiring, a second one after the Sachse conversion.

Compliments! Your diagrams are very good for an electrically untrained person. They show you are able to use your brain

Now we got the r/r unit out of the way, i can shift to other components in my search for a spark.

Meanwhile, and of course i should have checked that first, i found out that my 6 volt Energysafe battery is severely crippled. It won't give more than 4,5 Volt, which is just too little to activate the Sachse system.

I tested my Sparcon 6 volt trickle charger not connected to the battery and it appears to put out 9 Volt. So all winter my 6 Volt battery has been fed with 9 Volt? Or is the thing supposed to put out that much Volt initially and scale down accordingly to the demand of the battery?

I don't know this Sparcon 6 device. But I do not wonder about an unloaded output of 9 Volt. Connect the charger to a 6 Volt bulb of a power rating
P = 7 Volt * Iout(charger rating) and measure the voltage across the output. I presume you will find ~7 Volt.

Hooked up to the battery, the charger wont put out more than 4,5 Volt.
Tried to charge the battery with a different, old school -non trickle- charger with variable voltage, but all red warning lights it has light up when the voltage exceeds ca. 4,5 Volt.

This battery is dead as can be. Seems one cell is shorted. Forget about it, recycle it. And the charger's voltage you measured tells us it will settle to the voltage given by the batteries charge state.

Kind of confused here. Is a 6 Volt charger supposed to put out 9 Volt when not connected to a battery?

Of course this can happen with no load (see above).

Ordered a new (conventional lead acid) battery this morning. Comes uncharged, so i have to charge it myself. Before ruining another battery i need to know if my (preferred) 6 Volt trickle charger is in good order.

Trickle charging is not the best for lead-acid batteries. Hysteresis or float charging should be preferred. Some modern chargers have this mode. Read here: https://batteryuniversity.com/learn/article/charging_the_lead_acid_battery

Once i have a fully charged battery in good condition, i will continue the testing.
As a first step i will put the the Sachse unit into test mode. Good suggestion!
I suppose, with the Sachse unit in test mode, i have to hold the spark plug onto the engine to ground it?

When that works out well and i find a spark, get the bike running (assuming nothing else is wrong with fuel supply and/or carb), i will dive into testing the charging system, as you pointed out.

Thanks for putting me into the right direction guys!

Ciao,
Edwin

OK. Keep us informed about your results.

cheers Hans

Addendum: The alternators made for CDI ignition (Ducati and Motoplat) put out only ~75 Watt to the charging circuit, while those made for coil ignitions offer ~90 Watt. Reason: In the CDI versions, one of the 6 stator coils is an HV coil and connected separately to the CDI transducer, feeding the electronic circuit with ~15 Watt at ~ 300 Volt. Hence, when bikes with this stator are converted to points ignition, the HV stator coil idles, cannot contribute it's power to the charging system.

[@win]

Choose the 14 Volt/~ 1 Amp with a 12 Volt / 10 Watt bulb. I use this one:
Image
A leftover from my youth, when it powered electric railway models.

Haha, who would have thought these would come in handy 50 years later! Here's mine:

trixexpresstrafo.jpg

[@win]

cheers Hans

Addendum: The alternators made for CDI ignition (Ducati and Motoplat) put out only ~75 Watt to the charging circuit, while those made for coil ignitions offer ~90 Watt. Reason: In the CDI versions, one of the 6 stator coils is an HV coil and connected separately to the CDI transducer, feeding the electronic circuit with ~15 Watt at ~ 300 Volt. Hence, when bikes with this stator are converted to points ignition, the HV stator coil idles, cannot contribute it's power to the charging system.

That is good to know. That's the blue wire coming from the alternator that is no longer connected to the transducer after the Sachse conversion. See the diagram i posted. No longer needed/wanted, as the Sachse appears to be fully battery powered.
It also means my alternator puts out way less watts to the charging circuit than i thought: 75 Watt instead of the ~120 Watt i was told the wide case alternators are supposed to put out. And that while the Sachse unit needs a top-charged battery to wake up. So short rides could really wear the battery out?

Ciao,
Edwin

[ducwiz]

@Win,

I don't think that short rides will wear the battery, they will only drain her more and more, if you run mostly at low rpms. If you have a battery charger, connect it from time to time, or after each ride. Float or hysteresis charging should be preferred, trickle charging can indeed wear the battery out, i. e. when continuously connected during the winter season.
Longer rides are more dangerous - the balance between charging power and load consumption can be continuously on the negative side, and finally your battery is low while still on the road.
I never heard of 120 Watt alternator power for the italian 6Volt w/c models. Ducati claimed 90 Watt for the bikes with points ignition, 75 Watt for the later CDI models. Afaik, a few spanish models, equipped with 12 Volt systems from the outset, were listed with 100 or more Watt. I remember having measured the available output power of my 75 Watt Ducati alternator (CDI version) with the 6 Volt/halfwave rectifying system as well after my 12 Volt modification. The factory value could be confirmed for both cases, approximately. I also can confirm ~90 Watt max. output power for the points ignition alternator. My power values quoted, as well as those from the factory, refer to a system voltage of 6.8-7.0 Volt, or 13.6 - 14.0 V, respectively.

As I recall, Trix used DC for their model railways, from ~1953 on. As I was a Märklin enthusiast, I have no experience with the Trix transformers. But the little icons on top of yours indicate that it has a DC and an AC output, so you can promptly use the AC as the power source for the bulb.
But, if you want to use it's DC output to drive the R-R's control input, you might run into trouble. I presume, the DC coming from the output is pulsating, as it is not smoothed/filtered by a capacitor inside the transformer housing. In this case, you shou connect a large electrolytic capacitor in parallel with the DC output. With a pulsating voltage at the control input, the R-R might show strange behavior, and could be even damaged, becaus the peak voltage of the rectified pulses may exceed 10 Volt, while the measured average or RMS voltage is only 7 Volt.
Most suitable here is still a continuously variable and regulated/filtered lab power supply, example: https://www.circuitspecialists.com/csi1501.html

Hans

[Ventodue]

<snip> It also means my alternator puts out way less watts to the charging circuit than i thought: 75 Watt instead of the ~120 Watt i was told the wide case alternators are supposed to put out.

No. As Hans: no 6 volt Ducati single that I've heard of ever put out that much ...

So short rides could really wear the battery out?

No. It's not the duration of the ride that matters, it's how fast the alternator is turning. Poddle around for 3 hours in a parade and your battery will be dead. Run it round to the shops, revving its nuts off like a teenager, no problem .

[@win]

As I recall, Trix used DC for their model railways, from ~1953 on. As I was a Märklin enthusiast, I have no experience with the Trix transformers. But the little icons on top of yours indicate that it has a DC and an AC output, so you can promptly use the AC as the power source for the bulb.
But, if you want to use it's DC output to drive the R-R's control input, you might run into trouble. I presume, the DC coming from the output is pulsating, as it is not smoothed/filtered by a capacitor inside the transformer housing. In this case, you shou connect a large electrolytic capacitor in parallel with the DC output. With a pulsating voltage at the control input, the R-R might show strange behavior, and could be even damaged, becaus the peak voltage of the rectified pulses may exceed 10 Volt, while the measured average or RMS voltage is only 7 Volt.
Most suitable here is still a continuously variable and regulated/filtered lab power supply, example: https://www.circuitspecialists.com/csi1501.html
Hans

Hmmm.. this ruins the fun a little. Although, learning is fun too, isn't it.
I thought i'd use my TE transformer as both the AC as the DC source for the r/r unit test. As i understand now, to find out if the r/r unit is still working, there is a possibility that doing so, might actually break it.. and "then we are further from home"!

Obviously i had never heard of pulsed dc. I had to google it and found out that the wave of the AC current is cut in half and becomes DC (don't laugh), but there's still a wave. I assume that's what they call "ripple". And for the test of the r/r unit we want a DC power source with as little "ripple" as possible (Ripple: 0.3mV, in the example you linked to).

Unfortunately i can't find a way to tell if my transformer has a capacitor built in, or what it's "ripple" is. I could not find any 'technische daten' on the internet for the Siemens TE 5599 transformer. I understand that the ripple won't show when measuring with a normal volt meter. The only thing i know, is that the TE transformer was also advertised as a battery charger, but i don't know if that tells us anything about the "ripple" or the presence of a capacitor.

Conclusion: Best not to run that advanced r/r unit test with the equipment i have available. Charge the new battery and get the bike running, then perform the basic tests.

I never heard of 120 Watt alternator power for the italian 6Volt w/c models.

No. As Hans: no 6 volt Ducati single that I've heard of ever put out that much ...

I must have been misinformed or mixing things up again.

Thanks for elaborating guys!
Ciao
Edwin

[ducwiz]

@Win,

"pulsed DC" might have been the wrong espression. You know, my native language is german, I learned the english in school and practised it over the years rarely with british or US people, but with a lot of english speaking foreigners. Despite I work in the electonic business, I am still misunderstood sometimes cause I used inappropriate words.
Your google finding and the interpretation thereof is correct, there is nothing ridiculous with it. "Ripple" as I learned it is the periodic fluctuation af a DC voltage that was made from an AC wave, by rectifying, either half or full wave. Without a filter capacitor it is 100%, from zero to the peak voltage. With a cap and some regulating electronics it can be as low as you quoted from my link. A battery behaves as a strong filter, like a huge capacitor, and smoothens the ripple to near zero. All these effects would be visible on an oscilloscope, not an instrument available in the average motorcyclist shop. A simple voltmeter can only show the average DC voltage of the (unipolar) wave. Note: The average value of an AC voltage is Zero, it has no DC component.
If you don't know your transformer has only a rectifier inside but no cap, you can solve the problem by adding an external one. But find a large one, like 4700 micro-Farad (uF) or more, with a blocking voltage of 20 Volt minimum. Or, buy one of those cheap chinese variable DC adapters like this https://www.ebay.com/itm/Universal-Adjustable-AC-DC-Power-Adapter-Voltage-Regulated-48-60-72W-2-3-5A-Tool/153908605109?hash=item23d5aaf0b5:m:mo_fGzTtExgEx9kqoZYNDAA

Conclusion: Best not to run that advanced r/r unit test with the equipment i have available. Charge the new battery and get the bike running, then perform the basic tests.

That is the decision of a wise and patient man.

Btw, are you a US or a UK citizen?

Hans

[Ventodue]

I learned the english in school and practised it over the years ... <snip>

And very good it is too, Hans!