More crazy audio idea's from Gumby

[ https://www.thirdgen.org/techbb2/showthread.php?s=&threadid=146818 ]

Ok for 20 bucks I can get brand new battries, 500cca and 700cca.

I was gonna get a few for the heck of it, any ways could a batt be use like a cap, run it inline, it should pull most of the juice form the closer batt and use the main batt just a little bit. leaving lots of right now load like a cap available. and for 20 bucks.

I dont need too or it may not work as well but is it possiable???

 

batteries dont supply the current fast enough like a capacitor does.. only thing extra batteries do is let you play your system for longer with the car off (when the alternator isnt supplying voltage)

 

would the way i have it wired in the pic work??? would anything blow up??? is there a better way or lots of ways???

 

i guess it would work.. all it would accomplish would be added weight and a greater drain on your alternator tho...

 

Voltage adds in series. You would end up with a 24 v system, which is enough juice to burn stuff out. If you put them in parrallel then the voltage stays the same, but available amps would increase. Like mudaholic said, it will extend your play time with the motor off but it would not supply the quick voltage for power spikes like a cap would.

 

could you make a quick image showing the right was to wire it???

 

Wiring two batteries in parrallel would be like hooking up jumper cables. Positive to positive, negative to negative. It keeps the voltage at 12v, but adds the amps. If you run two 550 cca batteries, it would be like having a single 1100 cca battery. Good stuff for really cold winters or if you like to listen to the radio for extended periods with the engine off. But it won't help with voltage spikes caused by heavy bass. You'll need a cap for that.

 

Yea being so cold I swear Im about killing my 1000cca under the hood. When the car is warm its fine but this winter seams awful hard on my engine. I actually could use the extra amps,

 

Like everybody else said, all you'll get is more play time with the car not running. It will not provide any benefit when the vehicle is running, plus you'll have 2x the strain on the alternator, so you'll burn it up faster.

 

just thought id clear this up.... the alternator DOES NOT supply VOLTAGE, it DOES supply CURRENT (or amps to those who are not formiliar w/ the electrical terms. i would think your battery would not last long if it supplied voltage.

 

yes it does, it supplies current at a voltage.. when the alternator can't keep up with the demands of your electrical system then the battery helps out.. also, when the car is off (and thus the alterantor is not producing voltage (current if it makes it easier to understand)) then the battery has to do all the work.. if you have extra batteries then you have more ampere hours to work with, and you can sustain your systems demands for longer.. thats theo nly advantage to having extra batteries in this instance.

 

i dont mean to rude, but you are wrong. that first line is true but the alternator does not supply voltage just current. it seems that in the middle there you are trying to say that voltage is current. you seem to be contradicting yourself. i was not being rude to you before, i was trying to clear up what you said for the people who dont know so much about electronics.

 

umm...... where does the 14 volts in your electrical system come from then..?

 

ahhh, a good question. in electronics, as you may know, voltage is pressure. its the same as if you tried to stuff more air into a can than what would usually be in there. the pressure would go up. more or less, same basic concept.

 

tamu is the one mistaken.

An alternator supplies BOTH volatage and current. You cant have current flow without "pressure" (voltage) and a resistance to draw from it.

An alternator is a generator - it only does it's thing when it's running, or generating electricity.

An alternator charges a battery because the alternator is designed to supply higher voltage than the battery at low RPM's in a car where a normal battery would not be able to supply the necessary current at 12V. The alternator (being a generator) will supply more current at 12 or 14V than the battery can supply. In a car, the alternator will DECREASE voltage and current supplied as RPM's increase. This is the most commonly misunderstood part.
The alternator will put out higher voltage at lower engine revs, but at the expense of the amperage at higher engine revs.

This higher voltage put out at lower revs is what charges the battery. The alternator and battery are wired in parallel, so the weaker of the two sources (battery) will draw from the stronger (alternator) and therefore charge itself back up. Since the alternator is a generator, and supplies it's own electricity - that works fine. With two power sources in parallel, you will always see the weaker trying to degrade the stronger source. That is why you do NOT want to leave 2 batteries connected in parallel, but alternator/battery is fine. If using 2 batteries, the stronger battery will become degraded by the weaker constantly trying to match it's more powerful brother in the parallel circuit. In that case, the stronger battery will quickly become degraded trying to constantly feed the weaker battery rather than having no load (besides internally) sitting by itself.

An alternator supplies both voltage and current in parallel to a battery. This IS your charging system, and the alternator also runs all of your 12V sources while the car is running. If the alternator didn't supply voltage and your battery died, your car would immediately stop running. Since they are in parallel - as the battery drains, more and more load is placed on the charging capability of the alternator to recharge the battery, as well as run the accessories and fuel pump, etc..that is why you can drive a car for quite a while on a dead battery. As the battery reaches 0V, the parallelled alternator is being literally drained to death by the failing battery and will eventually stop spark, fuel pump, accessories, etc on your car. Naturally, when an alternator is subjected to this type of load and abuse, it will also degrade and often fails as well.

I hope this clears it up.

 

you made a simple subject very complicated. you are right that you cant have current without voltage, but like i said and so did whats his face, it supplies a current at a voltage. i guess if you want to be simple about it you can say it SUPPLIES a voltage but thats is more of a side note than what is happening.

i dont know where you got this info from but almost none of it makes since. last time i checked, if you rev your engine you will get more voltage. i have never gotten less voltage when i was reving.

your last two paragraphs there are just confussing. i have alot to say about them but im not gonna waist everybodies time with that and ill just say a couple of things.
1) it is ok to have multiple batteries in your car. it may not be a good idea to wire them in parrelel but its kind of a by occasion thing. whatever you do, make sure you have the same or similar batteries.
2) the thing about you saying you can run your car on a dead battery... that dont make no since man. it doesnt work like that. the alternator does run the system while the engine is running but it does it THROUGH the battery. if the battery is at 0V then you aint gettin no where. the alternator will recharge your battery if it is pretty dead when you start it but if your battery goes dead while your driving, your car will probably die.

im sorry if i caused any confussion to anyone here.

thanks

 

tamu...... I'm with you.

I've tried to explain that to guys on here, but they don't want to listen. It's a case of "if you tell yourself something long enough, you'll believe it whether it's true or not"...... or something like that.

Has ANYONE here ever gone out to a DEAD battery? I mean...... you left your interior light on for 24 hrs or more on a 20* night? If so...... you'd know that the car won't start...... right?

So you hook up another car to jump-start yours. You wait a little while for the battery to be charged up so you can start yours. Next you hop in, crank it over and it starts. So you get out, walk over and unhook the jumper cables and not 30 seconds later, your car dies????? Why???

BECAUSE THE BATTERY IS DEAD!!!!!!

IF you've never had this happen then you won't know what I'm talking about..... but ask some elders around you. They'll tell you their experiences, I'm sure.

AJ

 

I think they have what you call a battey isolator that lets the altornator charge both batterys at the same time, but dosnt let the batteries kill eachother on the same circuit.

 

start your car and disconnect your battery if you dont believe what we're saying.. your car will run indefinitely. (note: don't do this on a computer-controlled car, as it will probably kill the comp). in other words, once your car is running the battery is not NECESSARY (but its still very usefull.. disconnecting it would be pretty stupid so just trust me that it works)

furthermore, alternators implement a voltage regulator. this prevents the voltage from getting too high for your electrical system. i dont know how much experience you have with alternators, but when the regulator goes out your system can jump up to 20+ volts... this is not a problem with your battery, its the ALTERNATOR that is outputting the extraneous voltage.

i think this is a good topic to be discussing, although its not too pertinent to car audio--its still something a lot of people are not very educated about, so hopefully people are learning some valuable info from this discussion.

 

YOU JUST ANSWERED YOUR OWN QUESTION RIGHT THERE!!!!!!!

Why do you think you could screw up the computer if the battery has nothing to do with the car running????

AJ

 

Yes, no problems with an isolator there. You need one to prevent problems draining the batteries. My example was explaining how an alternator works in conjunction with a battery the same way 2 batteries would work without isolation.



Yes, the car dies because the battery is bad. It gets its jollies cranking your car over, then it's up to the alternator to take over. If the battery is too far gone, it will not provide a path for the alternators supply of current since it becomes internally either virtually open or vitrually shorted (depends on what happened to it). That is why your car dies, and thats how a bad battery can easily blowup & leak.

tamu,
This has to do with the alternator having a voltage regulator in the circuit. If it did not supply a voltage, it would not need one. Are you saying your battery is increasing voltage when you rev it? Thats a magic battery!

I don't understand how you would think it supplies ONLY current.? OHM's law applies to alternators, and supplying additional current without an increase in supply voltage or a decrease in resistance at the same voltage is impossible.
The fact that alternators supply additional voltage while the car is running takes into account the need to run all accessories as well as keep the battery charged.

Is it just me? C'mon guys, you can't have current supplied from the alternator without a voltage supplied from the alternator. Period. Check your battery voltage, then check your alternator voltage. If the alternator only supplied current - the voltages would match. Take the voltage regulator out of the alternator and you'll see some very dangerously high voltages for a 12V system. That is why some alternators put out 18V at idle, and 12V while cruising. The regulator is bad, or the alternator is from a transit bus or something that needs high voltage at slow speeds to supply A/C and accessories to a citybus full of 50 people. Alternators can be built to different specifications for different purposes, but they will ALWAYS supply a voltage.

Tamu - take the positive wire from the alternator to the battery and measure it's voltage. No ground, just the wire itself. It will show a positive voltage (or negative if you hooked it up backwards). The only way this is possible is if the alternator is a power supply in itself. It sees the battery as a load and is designed to keep the battery charged and at a constant voltage everytime the car runs. Keeping the battery's constant voltage, the battery can supply it's current as designed until the battery's electrodes quit generating and storing it's own energy properly.

 

sbcfreak is right here people. Those who disagree need to learn a thing or two about electricity.

 

ok sbc, we will say the alternator SUPPLIES voltage and current. if this makes it easier to understand than ok.

the voltage in the system, not the voltage of my "magic battery". what you said is total bs. connect a volt-meter to the battery and rev the engine and see what happens.

like i said current at a voltage.

how the hell would i check the voltage if i only had a positive lead? that doesnt make since. it is still direct current coming from the alternator to the battery isnt it? you tell me how i would do that and ill be more than happy to. but like i have said, "CURRENT AT A VOLTAGE".

oh and dont try and run your system with just the alternator and without the battery. that would be really retarded.

 

The battery's voltage is NOT increasing (unless it got drained to lower than 12V then it will increase to 12V). The HIGHER voltage of the alternator is being applied to the battery to CHARGE the battery. When you put a meter at the battery terminals you are reading the voltage from the alternator. The battery's charge never goes above 12 and change Volts.

 

i dont think that is entirely correct because i dont think you would get the higher numbers if the battery did not charge to that much. of course your statement does make since and it is a good basis to work with. i believe that this is a diffenent possibility. i was not taught this way but it is something i may look into.

oh and i never said the voltage is the battery's voltage, i said it was the system's voltage. i dont know if you were directing that sentence at me but i thought i would say it anyways.

 

to answer the first question for Gumby, No the Batteries in series (like you had in your drawing) will not work. I am an electronics guy myself. sorry guys, I'm not joining in the voltage/current argument......


make sure you have strong ground connections between your battery,engine block,chassis and amps.

get a multimeter set to test 12v DC and check for voltage drops (bad connections) see instructions in "body electrical" in haynes manual.

use lower gauge wires, clean the connecting surfaces as good as you can (wire brush)

this should help,upgrade to a stronger battery and alternator if neccesary. a cap will do the trick, but you shouldn't need one unless you are pulling some serious current...1000 watts rms or something like that.

 

Tamul30,

Put your Voltmeter on the positive connection at the alternator, and the other lead of the VM on the positive battery post. You will see a voltage there.

That is how you can easily check your charging system. If you see a voltage there, that means your alternator is charging your battery, and the voltage at the alternator is higher than the battery.

This is basic stuff. Don't be a fool and reply without knowing what you are talking about.

V/I*R is a formula representing OHM's law..work some numbers and get back to us. But don't be a stubborn *** and just blab just because you're wrong and can't admit it. How else are you supposed to learn if you think you know everything already?

This forum has some really really knowledgeable people, and their tips are greatly appreciated. But honestly, i think this forum is second only to the import forums for the amount of complete morons wasting space debating about what they think is right - even when the facts are right in front of them.

 

just to make you happy, i tried it how you said. put the positive lead to the alternator, negative to the positive on the battery. not suprisingly, there wasn't a voltage.

your right, this is basic stuff, but the problem is i dont know what YOU'RE talking about. i guess that makes you the fool then huh.

where did you find this equation? the proper equation for ohm's law is E=I*R (which is VOLTS=AMPS*RESISTANCE for those not formiliar with the apprev.). and what does it have to do with the discussion anyways. we are not trying to figure out the resistance in the system or anything.

if you are going to open your mouth about facts, make sure they are correct. i think i speak for the rest of the people in saying that you shouldnt be bad-mouthing this message board. when you have some logical facts, get back to me. until then, saying im a moron and dont know what im talking about does not hold water.

i dont know everything and neither do you. if you think im acting like i know everything you should look at what you said. wake up and smell the roses or toilet or whatever floats your boat.

 

V/I*R is the basis of the formula. It's not THE fomula.
It allows you to take any of those variables and divide/multiply by what you have and solve for the missing value.

Such as:
V/I = R
I*R = V
V/R = I

that was my point.

Anyway - you didnt get any voltage across that wire...was the car running? It's also possible the wire isn't "bad" enough to carry enough resistance for a voltage drop on your meter. But it *WILL* have a voltage drop on a multimeter with enough resolution in it's scale. If it's an analog meter - you probably wont notice it, but it's there.

Go start your car, then disconnect your battery. If the alternator isn't putting out voltage and current, your car will immediately die.

I cant wait to hear your response after that.

Have you ever started your car and it just barely cranked over, but you drove it all over the place? Then next time you got in it, the car was completely dead? Guess what - you just drove around on your alternator with a dead battery.

I by far know everything, but at least i know when i am wrong, and can admit it. If you truly think you are correct, thats fine. To settle the debate - go disconnect your battery with the car running and your answer will be right there. Just dont reconnect it while it's still running (as it will be) because you can spike your ECM and fry the chip. But that is another topic..

Nothing i've said is contradictory to the fact that *an alternator supplies voltage and current* in opposition to your statement that said it ONLY supplied current. Thats all I was trying to explain.

 

the way you put it makes the formula incorrect. if you say that thats the basis for it then whatever but it is quite confussion for us normal folk. and you never told me what ohm's law has to do with the discussion.

when i checked it, of course the car was running. alternator doesnt do anything if it isnt running. im not retarded.

i sure as hell aint gonna disconnect my battery with the car running. that is stupid and you being right or vice versa is not worth screwing something up on my car.

you have been trying to do alot of things besides explaining that, including trying to make me look stupid. dont try and say everything you have mentioned in the last few posts was you trying to prove your point. and again i said "CURRENT IS SUPPLIED AT A VOLTAGE". listen to what i am saying. when you give me some real proof i will admit that im wrong but right now, i am right and you are less than right.

 

you originally stated that the alternator supplied current only, not voltage. the V=IR equation states that, in a given circuit, there is VOLTAGE, CURRENT and RESISTANCE. you can't have an equation with only 2 of the three; thats the reason ohms law was brought into the equation in the first place.

 

you are correct, but as i have been saying, current at a voltage. i know the equation and how it works but you guys keep forgetting what i am saying.

CURRENT AT A VOLTAGE!!!!!

 

Hmmm lots of good info in this thread.

Ok most car, if its running and you unhook the battery, it should keep going. if it dies, your alt is bad.

I did it to my thridgen and wagon just weeks ago when I had only 1 battery and needed to move both cars.



But lets throw this out there and see how it flies.



Ok dead battery in my wagon, will just click. put 50 amp boost charger on it and it turn over and fires right up.

take out the battery, and just hook the 50amp boost to the cables, the car will barley click let alone turn over.


why does that dead battery need to be there, cause its a cap?

a battery charger cant put out enough to crank over an engine but even a dead battery will "act like a cap" so you can jump the car/ have enough now juice to turn it over.

try and jump start a car with no battery, it wont work.

a battery is a cap, even when dead or am I reading that wrong.

 

That's how you check the ampheres, not the voltage.

To test voltage you have to put the pos lead of the VM on the pos of the alt/batt/ or whatever, then the other lead (negative) to GROUND!!!!!

It's obvious that you're book smart, but not application smart.

And yes tamu...... the alt does produce voltage "AT CURRENT" because you can't have one without the other, nor without resistance. In all actuallity... you don't HAVE to have resistance. If you had ZERO resistance, then you'd still have voltage and amps, but that's in theory. Any wire is going to have resistance even if it's as small as .000000001 ohms or less.

And the battery does supply voltage to the amplifier. It has to. The alt regulator isn't quick enough to supply the variable current draws fast enough.

A week battery will cause a car to stop running even if it's jumped. That's because it's putting such a load on the alt, there isn't enough power FROM the battery NOR the alt. to run the ignition/ECM/ etc....

To say that the alt. does all the work, or that the battery does all the work is not true. Neither is true. It's a system. Kind of like a cam and heads. A bad pair of heads makes a good cam bad, and a bad cam makes good heads bad. Not that hard to figure out.

 

No, by hooking up the way sbcfreak said, the DMM is making a parallel circuit, and measuring VOLTAGE DROP do to resistance in the wire running between that battery and alt (do not confuse with voltage relative to ground!!). There should be very little drop, if there is alot, then there is high resistance in the wire--BAD!

In order to measure current, you would have to hook up the DMM in series, meaning disconneting the wire from the batt to alt and using the DMM terminals to carry the current *note-most DMMs cant handle the amount of current your alt can make, so don't try this at home

 

You're right.

I guess I shouldn't read this stuff at 2 am and wait to help when I'm well rested.

 

I found this....
-------------------------------


This is an edited article based on one that was in more detail and
pertained more specifically to BMW airhead motorcycles....I am
posting it to give some BASICS on electricity; and, the approach
used here is different than in the manuals and troubleshooting
guides that you might have, or are contemplating obtaining. NOTE
that many popular manuals such as the ones published by such as
Clymers and Haynes, often have some serious errors.

A schematic diagram of your bikes electrical wiring is a nice thing
to have, as well as any specifics on electronics and perhaps hints
on out of the ordinary type of systems/parts/etc.

Much of the following is rather simplified, no flaming from fellow
engineers, please!

Electricity is easiest to think of (??), as a flow of electrons.
Electrons are whirling submicroscopic parts of atomic structure.
These little bits have a 'charge'. Get enough of these little
charges (zillions) moving through a wire, and you have a flow of
CURRENT. Apply the flow to something like a lamp, and if enough are
flowing, the lamp will heat up, and might even put out light. Too
much flow, the lamp burns out, just like a fuse, which blows for
excessive current flow. Current flow is measured in amperes, and in
many cases, very tiny parts of amperes, such as milliamperes or
microamperes.

It is still sort of popular to use analogy of water pipes to explain
electricity. I find that this often confuses folks a lot. Water
pressure IS the force, like voltage, that ALLOWS more flow from the
faucet, at a given faucet opening. That adjustable opening IS like
resistance (ohms). The rest of the usual story, often confuses. I
won't get into it here.

In order to have a CURRENT FLOWING, it must begin someplace, travel
COMPLETELY through a 'circuit' and thus be returned to the source.
A battery may have an excess of electrons at one terminal, compared
to the other terminal, but NO current (other than internal leakage)
is flowing. If you connected the terminals directly, current (a
nasty big fire causing type) will flow. You need to have the device
to be powered, a lamp for instance, connected, somehow, to BOTH
battery terminals, for electrons to flow THROUGH the device, and the
battery too.

When electrons flow through something that allows such a flow
(usually metallic), the properties of the CONDUCTOR (as I said,
usually metallic, often a 'wire') are such that the conductor itself
offers SOME 'resistance' to the flow. Example: A thin wire would
offer much more resistance to flow to your starter motor, than a
much thicker wire. Resistance is generally undesirable in our
bikes. You can't get away from it, however.

In electronics, devices such as 'RESISTORS' are used to actually, on
purpose, restrict electron flow.

In some bikes and cars the resistance of the GENerator or ALTernator
lamp has the purpose of being the resistor that restricts and
supplies through it, the initializing current to the alternator
rotor to allow the beginning of alternator output. Your alternator
must have a certain number of turns of wire, in order to obtain
proper VOLTAGE output. Voltage is the pressure that the electrons
can exert. If we wanted to reduce the resistance (the unit of
measurement is OHMS) of the fixed physical size alternator to allow
more CURRENT output, we need either a lower resistance wire via
larger diameter wire, or, a metal that flows electrons with less
resistance. Both of these
are usually impractical, but a larger physical alternator, if it
would fit, could contain more wire or larger wire or both, and a
larger rotor to enable a bigger output overall. The only conductor
that is better than copper, that
could conceivably be considered is almost pure silver!

So far I have mentioned amperes, volts, and ohms. When current
(amperes) is flowing, in a resistance (ohms), due to being forced
through the conductor by pressure (voltage), HEAT is produced. In
some instances the heat is desirable or necessary, like in an
incandescent lamp. In other cases the heat is not desirable, even a
bad thing. Semiconductor 'things' like diodes and transistors, do
NOT like heat. Specifically they do not like excessive heat, and
also do not like to be cycled, cold/hot/cold....This cycling tends
to bring about failures from molecular sized faults in the
manufacturing process. Microscopic cracks, if you will. In many
types of electronics equipment, excessive heat causes the circuitry
to fail, sometimes in intermittent ways.

When current flows, heat, or work, or whatever, is done...whichever
way you want to think about it. Work being done has a unit of
measurement called WATTS, and it just so happens that there are some
very specific, dyed-in-the-wool specifics about the relationships
between amperes, volts, ohms, watts:
volts multiplied by amperes equals watts.
746 watts is one horsepower.
Ohms equals volts divided by amperes.
Engine output is sometime specified in so many Kw (Kilowatt, a
thousand watts).

>From the above, any value can be obtained from any two known values!

If the flow of electricity is restricted by such as a too thin wire
(like maybe some broken strands...), badly corroded connections,
sulfated battery, etc., than we say that there is 'excessive
resistance'.

Voltage is typically measured by allowing a very small amount of the
current to be diverted from a circuit under test, and applying that
diversion to circuitry, or an old fashioned analog meter, in such a
way as to have a calibrated reading. So, the metering device
usually 'pulls a tad of current, itself'. That fact can, in SOME
circumstances, affect the meter reading. For practical purposes,
that is unlikely to affect readings for anything but electronics
circuitry.

Ohms is typically measured by applying a voltage to the part under
test, by internal meter circuitry, in such a way, that the current
flow is indicated on the meter, but calibrated for the effective
resistance in the circuit. That is why almost all ohmmeters contain
a small battery. Some devices, such as diodes, are tested by means
of an ohmmeter (as well as other tests). A diode, once the applied
voltage is high enough (roughly half a volt), must pass current in
one direction, and not in the other (or, very very little). If the
ohmmeter does not apply enough voltage and also current, to the
diode, the diode may well not 'turn on' in the so-called 'forward
direction'. This DOES happen on some, usually very expensive
digital meters, that on purpose use very low currents, to avoid
damaging sensitive devices that might be connected to the meter. Do
not purchase a meter unless it tests diodes adequately, on its
ohmmeter AND diode test functions (if it has both). The ohmmeter
readings on such a meter might be so weird as to be unusable.

So, the applied voltage AT the diode, must be at least half a volt
or more, for most diodes to 'turn on' in one direction. Some types
of diodes are specifically made for some 'strange' functions. A
'Zener diode' is used in your electronics type voltage regulator,
and some tachometers, and plenty of electronics items, to regulate
the voltage...or provide a reference for that type of function.
There are diodes used in your CD player, called laser diodes. These
emit a type of infrared narrow beam of light. There may be plenty
of other diodes in the rest of your motorcycle, including the
alternator output rectifying diodes, and may be small diodes here
and there in the bike for other purposes.

Diodes, in the forward, turned-on direction, can be thought of as
having an inherent internal resistance, since they have an internal
voltage drop of roughly half a volt for most types. Hence, they
can, with enough current
flowing, develop a lot of heat.

The electricity in your home is AC (alternating current). What this
means is that for over any portion of time (you name it), the power
at the wall socket is such that its VOLTAGE is constantly varying,
going up and down, and in fact, becomes ZERO, as it follows a CURVE
that mathematically is called a SINE WAVE. When this 'WAVEFORM'
goes from zero to maximum positive, back down to zero and back to
maximum negative, and back to zero, that is called 'ONE CYCLE'.
Cycles per second gave way many years ago to the term HERTZ, to
honor Mr. Hertz. In your home, the number of cycles per second, is
60. This value is kept
very accurately by your power company...so accurately that old
fashioned electric motor clocks run VERY accurately.

Alternating current has one HUGE advantage over Direct Current, it
can be transformed. What this means is that a device called a
transformer...nothing more than a specially designed magnetic steel
structure, with some turns of wire on it....and another such 'COIL'
of more turns of wire, the two generally being electrically
separated...can change an input voltage to a lower or higher output
voltage. Since we have learned that POWER (watts) is voltage
times amperes, this means that if we can transform the POWER of a
power plant to a super high
voltage, many thousands, in fact up to half a million is in usage,
we get the same POWER at a much lower CURRENT (amperes),........we
would need only a much thinner than otherwise wire, to carry energy
for many miles, where at the other end, we could transform the
voltage downward...say to 220 or 110. Otherwise, the wiring to our
homes and businesses might, in some cases, be as thick as many
feet! Vehicles used to be mostly 6 volts, 12 volts is standard
now, some trucks use 24, and the coming trend for vehicles is likely
going to be 24 or 48.
This allows thinner wire and also allows for higher efficiency in
many things.

The transformation idea is actually done in your alternator,
magnetically, from the induced field from the rotor, and some other
effects in the stator...but this is far too complicated to explain
in this article...BUT, the only place this type of thing is done
DIRECTLY in your bike, is the ignition coil, which by
trickery, has a DC voltage applied that is made to act like a form
of AC, and that is applied to a moderately low number of PRIMARY
winding turns....and the SECONDARY winding has many thousands of
turns. It is a property of transformers that the ratio of the
number of turns of primary and of secondary determines the step up
(could be used backwards as step down).

In your bike, the source of electricity is the battery, which, if in
good condition, has an INTERNAL RESISTANCE which is very low, a
small fraction of an ohm...which is why dangerous currents (like
melting things type of levels) can flow with short circuits. The
battery must be constantly recharged, from its inherent self
discharge during the time the motorcycle is not driven, old flooded
types often as much as 1/3 OR MORE in a month in hot weather,
(..more, if you have a clock, less, without)...and, of course, from
drain from the lamps, ignition, etc., while riding the bike.

A true generator produces DC, and it would be less efficient and
likely much larger, and its brushes would not last very long, and
they tend to spark a lot and create other problems, so
manufacturer's have elected to use a type of generator called an
alternator. The name means that its output is alternating
current...that sine wave thing again ...and the frequency (number of
CYCLES per second or HERTZ) varies with engine speed. When the
frequency is high enough, and your attached radio is not filtered
well, some of the alternator noise
may show up on your radio as a whine. A poor diode tends to create a
big electrical noise output.

In order to charge the battery, the AC must be RECTIFIED, that is,
converted to DC (Direct Current)....which is done by the large
diodes in the diode board. The one diode section of three diodes
allows only the positive half of the AC to go to the battery
(positive post), and the other diode section of three diodes
allows only the negative half of the AC to go to the battery
(negative post).

The alternator used on most motorcycles does not produce just one
sine wave output...but, for efficiency...is designed to have
three...'THREE PHASES'. This
means that if a single cycle of waveform is 360 degrees, that the
alternator,
WITH REFERENCE TO any ONE of its output phase connections, is
producing output every 120 degrees...during that 360 degree period.
(boy have I simplified this ....don't climb on 'ol snowbum here).

These three waveforms are rectified by three positive and three
negative
diodes. There are likely other diodes, I won't discuss them much
here., too complicated, but they may be rectifying a smaller current
from perhaps the centertap of the alternator stator winding. As an
example of a popular system, in the BMW motorcycles, there is a
diode board containing all the alternator required diodes, and it
has a small set of diodes, which do exactly the same thing as the
larger ones, but are only used to provide a SMALL amount of current,
for 'sensing' the voltage of the alternator, versus the battery, by
the voltage regulator. In the Bosch-BMW system, the regulator does
not exactly and directly sense the battery voltage. Nor does it do
this at the big diode outputs.

If a large diode in the diode board short circuits, it allows the
entire AC waveform to pass, causing a huge current flow, and usually
charring/burning, and a gross failure. If that diode OPENS, then
you will lose far more than just 1/6th of the alternator output, due
to complex interaction of the waveforms, diodes, and magnetic
fields. This type of failure is hard to diagnose sometimes.
Symptoms could included a battery that MIGHT seem to fully charge,
with correct battery voltage; yet, when enough load is put on the
bike's
system...such as the headlight light, or heated
clothing...etc....the voltage
will not come up far enough. Since other faults can mimic this
one, it takes some sleuthing. It is a rare event, but does happen.

Diodes are usually best checked out of the motorcycle...and with
both
an ohmmeter for forward and reverse resistance, and by an
alternating voltage source with a lamp. On a practical basis, since
diodes can act funny if hot or cold, a really **** person would
check them at room temperature, and then repeat all measurements
around boiling water temperature, and at freezer temperature.

 

wassaap
this is very educational post
Quick someone make it stickey -seriously-