solar trickle charger and alternator

[wingdood]

hi,

I was thinking about buying a solar trickle charger to increase my FE, but then I realized that it wouldn't make a difference if the alternator for the Yaris was not load sensitive (alternator still runs when the battery is fully charged).

Does anyone know for sure if the alternator for the Yaris is load sensitive?

[cali yaris]

Since the alternator is on a fixed pulley, it's always spinning and always causing some parasitic power loss on the system.

Is that what you mean by load sensitive?

[wingdood]

Originally Posted by cali yaris

Since the alternator is on a fixed pulley, it's always spinning and always causing some parasitic power loss on the system.

Is that what you mean by load sensitive?

kinda...I mean..does the alternator check for the voltage in the battery and adjust its amount of spinning when it knows how much recharge it needs to do?

[cali yaris]

No. It's on a belt, along with the crank pulley, the water pump and the A/C. So it spins with the motor regardless of of whether it is charging the system or not.

[silver_echo]

it varies the charge rate based on sensing the voltage in the system, by adjusting the electromagnetic field in the alternator... this is varied by the voltage regulator, which is connected to the rotor inside... the then powered rotor spins past the stator which causes electromagnetic induction, which is power generation... the power is generated as three phase, alternating(AC) current, which then flows through the rectifier which is a stack of 6 diodes(one way electricity valves) and then comes out of the alternator as DC current... if you feel like reading, take a look at this...





Description: The alternator consists of a spinning set of electrical windings
called a rotor, a stationary set of windings called a stator, a rectifier
assembly, a set of brushes to maintain electrical contact with the rotor, and
a pulley. All of these parts except the pulley are contained in an aluminum
housing. Today?s alternators use compact, electronic voltage regulators
that may be housed inside the alternator or the voltage regulator function
may be handled by the vehicle?s powertrain control module (PCM).


Purpose: The alternator generates direct current for recharging the battery
and for powering vehicle electrical loads.


Maintenance Tips/Suggestions: Have the alternator?s drive belt tension
checked at every oil change. A loose belt can reduce alternator output and
run down your car?s battery. Each spring, prior to travel season, it?s wise
to have your car?s charging system tested as part of a comprehensive
starting, charging and battery test. This test will determine whether your
car?s alternator is putting out the proper amount of current and voltage.
Your car?s alternator is designed to recharge the battery after slight
discharging such as engine starting; the alternator is not designed for
charging heavily discharged (?dead?) batteries. Relying on the alternator to
charge a heavily discharged battery can overload the alternator and cause
damage. In such cases, use a battery charger instead. An alternator
problem can cause a discharged battery, poor accessory and light
operation, frequent bulb replacement, repeat voltage regulator failures,
erratic engine operation, or a dashboard warning light to illuminate. To
pinpoint the cause, have your car?s charging system checked out by a
qualified service technician. Life expectancy of the average alternator is
75-100 thousand miles.
Standard Automobile Alternator
A key component of an automobile's charging system, which provides
current to recharge the battery and develops electricity to power all other
electrical components when the engine is running, is the alternator. The
other component of the charging system is the voltage regulator. The basic
function of the alternator is to generate the electricity required to start and
run the automobile, while the regulator is designed to control the amount of
voltage that circulates through the system. This discussion will focus entirely
upon the alternator, specifically, the principle of operation by which it works
and its main components. An alternator (Fig. 1) consists of rotor assembly,
a stator assembly, and a rectifier mounted in a housing.
Figure 1. Parts of an Alternator




















Alternator Housing. The housing is usually made up of two pieces of die-cast
aluminum. Aluminum is used because it is a nonmagnetic, lightweight
material that provides good heat dissipation. Bearings supporting the rotor
assembly are mounted in the front and rear housing. The front bearing is
usually pressed into the front housing or onto the rotor shaft. It is usually a
factory-lubricated ball bearing. The rear bearing is usually installed with a
light press fit in the rear housing.

Stator Assembly. The stator is clamped between the front and the rear
housing. A number of steel stampings are riveted together to form its frame.
Three windings around the stator frame are arranged in layers in each of the
slots on the frame. At the other end, they are connected into the rectification
assembly.

Rotor Assembly. The rotor assembly consists of a rotor shaft, a winding
around an iron core, two pole pieces, and slip rings. The rotor is pressed
into the core. Six-fingered, malleable, iron pole pieces are pressed onto the
shaft against each end of the winding core. They are placed so that the
fingers mesh but do not touch. When direct current is passed through the
field coil winding, the fingers become alternately north and south poles. A
slip ring assembly is pressed on to the rear end of the rotor shaft and
connected to the two ends of the field winding.

Two brushes are held against the slip rings by springs, usually mounted in
plastic brush holders that support the brushes and prevent brush sticking.
Each brush is connected into the circuit by a flexible copper lead wire. The
brushes ride on the slip rings and are connected through a switch to the
battery. When the switch is closed, current from the battery passes through
one brush, through the slip ring, and then through the field winding. After
leaving the field winding, current flows through the other slip ring and brush
before returning to the battery through the ground return path. The flow of
electrical energy through the field winding, called field current, creates the
magnetic field for the rotor.

Rectifier Assembly. The rectifier assembly consists of six diodes mounted
either in the rear housing or in a separate small housing called a rectifier
bridge. Three of the diodes are connected to ground, and three are mounted
in an insulator. Since the mounting assembly carries off heat caused by the
operation of the diode, it is often called a heat sink.

A fan and pulley assembly is either pressed onto the rotor shaft or held with
a nut. The pulley drives the rotor through an engine accessory drive belt.
The fan behind the alternator pulley pulls air in through vents at the rear of
the alternator to cool the diodes.

[ka0sx]

well defined.

[silver_echo]

thank you... i just finished learning about auto electric systems last quarter at spokane community college

[yaris-me]

Originally Posted by wingdood

hi,

I was thinking about buying a solar trickle charger to increase my FE, but then I realized that it wouldn't make a difference if the alternator for the Yaris was not load sensitive (alternator still runs when the battery is fully charged).

Does anyone know for sure if the alternator for the Yaris is load sensitive?

I believe the answer is yes.

[daf62757]

Originally Posted by silver_echo

thank you... i just finished learning about auto electric systems last quarter at spokane community college

Hey...I have to fly to Spokane at the end of the month. Is there any really great restaurants that are a must do in Spokane?

[cali yaris]

I believe the answer is yes.

I'll say again that it's on a fixed pulley (not a clutch pulley) and therefore there is constant parasitic mechanical power drain, regardless of how much electricity it is producing for the car.

Have I got that wrong somehow?

[silver_echo]

Originally Posted by daf62757

Hey...I have to fly to Spokane at the end of the month. Is there any really great restaurants that are a must do in Spokane?

depends on how much you want to spend... clinkerdaggers is pretty good but expensive... also depends on what kind of food you like... let me know what you like to eat... pm me

[silver_echo]

Originally Posted by cali yaris

I'll say again that it's on a fixed pulley (not a clutch pulley) and therefore there is constant parasitic mechanical power drain, regardless of how much electricity it is producing for the car.

Have I got that wrong somehow?

yes there is a mechanical drain, but it is very minimal... the larger portion of the drain is how much energy is being used by the alternater to magnetize the rotor of the alternater... i will look it up in my book and type in the section of the chapter from the auto electric book on this when i get home later

[yaris-me]

Originally Posted by cali yaris

I'll say again that it's on a fixed pulley (not a clutch pulley) and therefore there is constant parasitic mechanical power drain, regardless of how much electricity it is producing for the car.

Have I got that wrong somehow?

Alternators are load sensitive. The regulator keeps the voltage constant. When there is a greater power draw, the alternator produces more current so the voltage can be maintained. Therefore it is load sensitive.

The mechanical power drain would increase with increased power draw.

[sqall12001]

They are on a pulley yes, but the regulator increases the "Field strength" to increase amperage output of the alternator, so when the Car needs more juice, the engine will work harder to spin the armature through the field windings.

-Nick

[daf62757]

Originally Posted by silver_echo

depends on how much you want to spend... clinkerdaggers is pretty good but expensive... also depends on what kind of food you like... let me know what you like to eat... pm me

Anything under $30.00 a meal.....I eat anything that doesn't eat me first!

[silver_echo]

Originally Posted by daf62757

Anything under $30.00 a meal.....I eat anything that doesn't eat me first!

well if you want cheap, there is a burger place in downtown spokane that is good and very inexpensive... "dick's hamburgers"

when you gonna be in town? how long?

[cali yaris]

They are on a pulley yes, but the regulator increases the "Field strength" to increase amperage output of the alternator, so when the Car needs more juice, the engine will work harder to spin the armature through the field windings.

ah, cool, thanks.

I didn't know that the mechanical resistance increased or was variable. I figured the alternator makes what it makes at all times and the electricity produced was regulated into the system a different way.

when the Car needs more juice, the engine will work harder

How much harder?

[wingdood]

so just to be clear

when a solar trickle charger is used, the car battery is always fully charged, the amperage output of the alternator doesn't need to be increased, the engine doesn't need to work harder, and fuel is saved....correct?