Charging System

[George R. Garrison #0857]

W E L L - A voltage gage reads just that VOLTS (the EMF - elctro motive force) This is a static force.

AMPS or Amperage, is the current moving in the circuit or component, the flow. E over I x R.

R being the resistance in the circuit or component. E being the volts and I being the amps.

This is all basic stuff, and the volts and amps are different.

I think the voltmeter will read the volts. As the regulating system kicks in the volts will increase, but this is not amps. As you turn on more loads or resistances, the flow or amps will increase and this is read on an ampmeter.

Think of volts as pressure held and waiting to do something. Once a valves opened the amps move as a flow of fluid and there measured on a flow meter or ampmeter if it be electric.

I'm stupid, but that my story and I'm sticking to it.

Later, George in Delaware

[twinegar]

You don't sound stupid to me. It sounds like you have some electrical training that I wish I had.
I am getting a lot of good input on this topic and am glad I asked.
If the meter reads below 12 volts when first fired up and for the first few minutes driving, is this an indication that the clutch plates are slipping and how much can I safely shim the tension spring? I have two thin washers in there now that equal about 3/32" and it helped a lot but it appears I may need a little more shimming to stop the slipping. My 79 must be set up perfect because it immediately goes to 12.2 V on start up and never drops below that regardless of the load.

[George R. Garrison #0857]

Okay, now, I'm answering purely on theory, BUT, after starting you pull the voltage down,, the battery is down in volts. The generator or alternator, if operating properly will charge at a rate of about 12.7 volts. This is not amps. On an amp meter after starting you will see a rate of charge to the right of zero. As the battery reaches its full capacity the needle on an amp meter will slowly move towards zero. At zero the battery and charging system are at the same point. The battery needs nothing and the charging alternator in this case will provided nothing until a difference occurs.

If the alternator cannot keep up due to excessive loads, or if a belt is slipping or if the drive is slipping, this will get worse as engine speed increases OR load on electrical system increases and if the alternator drive is an oil bath drive, the engine oil temp will increase and engine oil pressure MAY decrease.

Heat in a gas engine has a negative performance effect so as the whole dam thing gets hotter the powerplant suffers in power output.

Diesel engines love heat, gas engines do not.

I do not have a clue regarding the shim thing, someone on here must know the proper thickness and spring tension needed within the alternator or drive.

I hope I do not have this problem with my 81 Pro-link, but she's not been started in years.

Later, George in Delaware

[EMS]

W E L L - A voltage gage reads just that VOLTS (the EMF - elctro motive force) This is a static force.

AMPS or Amperage, is the current moving in the circuit or component, the flow. E over I x R.

R being the resistance in the circuit or component. E being the volts and I being the amps.

This is all basic stuff, and the volts and amps are different.

I think the voltmeter will read the volts.

So, how do you build an instrument that reads "Volts". It is the static potential between two poles. Try to talk to an electrical engineer and have him explain it.
Just that relationship that you explain above, commonly known as the "Law of Ohm" is the base for the possible function of a "Voltage Meter"

[George R. Garrison #0857]

Okay, a volt meter has two posts. One for negative and one for positive. Connect it across the battery with is a large mullti cell capacitor and you will read the voltage of a the battery. This reading is of a static force. The volts are not going any where. At least most volt gauges or voltmeters are designed in a way that they consume an minimal amount amount to read either digitally or analog with a needle. Each cell in a conventional batteries 1 and 1/2 volts. So, a 12 volt battery has 8 cells and connected in series and the volt meter connects to the negative of the first cell and the positive of the last cell and reads 12 voltage of calibrated needle deflection.

Now, insert a resistance R in to the simple circuit. Disconnect the positive lead hooking the volt meter to the battery and install a light bulb. The bulb will light and a noticeable change of voltage will be seen on the volt meter. Your reducing the voltage of the battery (the power source) by the rate of the resistance and eventually the volts will be reduced. You are reducing the capacity of the battery. And reducing the volts.

But, the rate at which you reduce the capacity of the volts in the battery is read on an Amp meter. The is the rate of the flow of volts that are being used by the bulb. P over I X E
will give your the watts that are the result of using (volts) are a given rate of (amps hours).

Measure this in 1000's, kilo watts and that's what the electric company uses to measure your house electric usage. Your meter on your home is an amp meter calibrated to read in kilowatts. If you where to open your meter panel and connect a voltmeter across the main lugs you would read a static force known as volts. That force should remain steady regardless of the amount of current (amps) that you use.

When you go on vacation and leave your house, the volts are always there ready to force the current to a resistance when a switch is turned on. But, if no switches are turned on and no volts are used during that period of time, there will be no current usage (amps) and you meter will not move and your bill will be zero for that period of time. Of course the power company will bill you for a minimum and other delivery charges for the associated time but you used no power. So, in the case of a meter on a boat slip under private authority and local billing, you'd use no power and receive no bill cause you used no amps. But, during that period of time the volts would always be displayed on a gauge hooked across the meter as a force waiting to be used.

Dam, now after saying all that I know I'm stupid. I need to check my ammeter to see what rate of amps I'm using so I don't run out before getting recharged. My volts may be getting low.

Later, George in Delaware

[EMS]

You describe it perfectly, George. As soon as you connect the Voltmeter with its two poles across the battery, a current will flow. It will be very very small, because the resistance in the instrument is large. Due the relation based on the formula you describe, the instrument will use this little current (amperage) and indicate a related Volt amount.
It's just that this is how these instruments are built. If there was no current flowing, it could not indicate a voltage. The smaller the resistance (light bulb), the higher the current and the result is a voltage drop. There is no way to measure "Volt" as a static force without using the current flow from one pole to the other that it produces.

[George R. Garrison #0857]

S O, I stand my ground......I am STUPID!

Later, George in Delaware

[twinegar]

I guess the person that seemed to know about shimming hasn't read my post. During my search of the forum archives I did run across a guy talking about shimming the tension spring in order to stop unnecessary slipping but can't seem to find his comments again. I will go with what I think I have learned here and from my own experience and will shim a small amount each time until the slipping is halted. I doubt any amount of shimming would keep the plates from slipping during the critical moment that the design was intended to address.

[EMS]

twinegar: Do you have a service manual? In there it gives the service limit for the uncompressed spring height. I would start from there and compare this with the actual height for your spring. Add a shim thickness to get back slightly above the service limit number. You don't want to compress the spring too much.
I would assume the guy you are waiting for to chime in is Dave McMunn.

[spencer]

I'd say you are both right, but George is closer to real life. In a volt meter, the resistance is so high that the current which flows through it is small enough that it can be considered to be zero.

Comparing electricity to water is a good analogy. Volts is comparable to water pressure. It's there whether water is flowing or not. Current is comparable to water flowing. When you open a valve, to allow water to flow, the pressure drops, just like voltage drops whenever current flows.

Just my two cents worth.

[EMS]

This from another source:

A voltmeter is a device used to measure the voltage potential between two points in an electrical circuit. First created in the early 1800s, voltmeters were originally called galvanometers. Technically, all voltmeters are ammeters, as they measure current rather than voltage. Although current is measured in amps, Ohm's Law, which establishes the relationship between voltage, current and resistance, can be used to scale the amps to volts.

Voltmeters were made possible by an 1819 discovery by Hans Oersted. When he passed a current through a wire near a compass needle, he noticed the needle would change direction. The earliest attempts to take advantage of this effect were little more than a coil of wire wrapped around a compass; the stronger the current passing through the wire, the greater the deflection of the compass needle. While functional, these early models were not very accurate.

[EMS]

One other thing on 12V batteries: A conventional automotive/mobile 12V battery consists of six cells, each at 2.1-2.3 Volts depending on construction. Thus, a fully charged battery measured with a precise, calibrated instrument will show a charge of 6x 2.3V = 13.8 Volts maximum, sometimes only 12.6 Volt. Any attempts to get more out of (or into) the battery will result in overheating or gassing-out of the battery and potentially doing more harm than good.
A typical charge system provides a fixed voltage of typically 13.8 to 14.4 Volt, but that doesn't mean the battery will assume that voltage level when fully charged.
Again, if you don't believe me, talk to an electric engineer or a physicist. Sometimes, people who work with that stuff for a living, can be trusted. At least more than all those shade-tree mechanics with decades of garage experience.

[Don]

Strictly speaking, there is no such thing as a Voltmeter. They are all ampere meters. A voltmeter just takes the measured ampere and converts it over a specified resistance into Volts

. . . . and, technically speaking, there is no such thing as an ammeter - An ammeter is actually a voltmeter which measures the voltage drop across a calibrated resistance (a shunt) and translates that measured voltage drop across the shunt into amperes displayed on the front panel scale ;)

Which came first . . . . the chicken or the egg?

Don

[EMS]

Sorry, Don, but I have to remain opposed to that belief. No instrument can measure volt. They all measure a current. What you are describing is how the instrument indicates "Volt" by measuring a current against a defined resistance. I would like to know, how you construct an instrument that can measure a "voltage drop" and unless someone comes up with an explanation I stick to what my physics teacher in high school and my electronics professors at university told me.

[twinegar]

Well......................after reading my initial post and following the responses to the end I sure opened a can of worms.
For whatever it's worth here is my observation:
If you start the bike and the volt needle doesn't sweep up to 12 volts and like mine sits at a little over 11 volts then the plates are slipping. More proof is if you either let it sit at high idle or drive for two or three minutes and then the needle sort of twitches a couple of times and then climbs to normal charge range in accordance to the rpm the plates are slipping. My 80 does this , my 79 does not so I will get with our beloved Louis and see if he has a new clutch tension spring and take it from there. It would be interesting to unplug the head lamp and driving lights just to see if that is enough to keep the plates from slipping at start up. If the new spring doesn't quite fix it then I will shim to reel it in.............or blame it on the Chinese bearings I installed.
Either or......I shall prevail.