Automatic transmission(Automatic gearbox) have been around for
sometimes now.It was invented in 1921 by Alfred Hormer Munro of
Regina,Saskatchewan Canada,so definitely its a familiar system in Auto
world.Automatic transmission is a gear system/transmission system that
automatically select gear ratios,velocity and movement base on the speed
of the car freeing the driver from the shifting the gears manually.
Automatic transmissions can also be driven like manual transmissions Manual mode M or +,- mode.
The US standard have modes ordered
P R N D L prior this mode arrangement is the
P N D L R
ever since the US standard mode arrangement there have been lot of
modifications and adjustment to this arrangement due to technological
advancement and need to include more efficient and high tech modes.
Automatic transmissions have different types of mode depending
on maker and model of the transmission.Below are some common modes in
Auto transmisssions
P (Park)
All auto transmissions have this mode,it mechanically restrict vehicle
from moving by preventing transmission from rotating,locking the output
of the shaft of transmission however some vehicle still tends to slip if
parked on a slopy edge or surface its then advised that the handbrake
be used after the selection gear have been shifted to park to prevent
total movement.Car engines can be started when the shifter is on mode
P(park) and N(neutral),this is because the open inhibitor switch all
known as neutral safety switch wired in series with the starter motor
engagement circuit is closed when P and N is selected.
R(Reverse)
This gear selection mode allows backward movement of the vehicle and it
activate a switch that turns on backup light for improved
vision.Selecting R in most vehicle the driver must come to a halt in
other not to damage the transmission however some modern auto
transmission have a safety mechanism which requires the brake pedal to
be matched in order to allow the selection of reverse.The shifter can
simply be move from R to N or N to D without depressing the button but
it can`t be shift back to R without depressing the button
N(Neutral)
This mode disengages all the gears with the transmission,hence it can
move freely on its own weight and gain momentum without force.The
vehicle might be stagnant if N mode is selected before the vehicle moves
and on a plane surface.
D(Drive)
The drive shift allows the transmission to activate its full range of
available forward gears and accelerate through it ranges of gears,the
gear ratio present depends on the maker and model four,five,six or over
OD(Overdrive)
OD is is used in some modern transmission system it allow early
computer controlled transmission to engage OD.The mode D locks off the
automatic OD though similar or identical otherwise but the OD is engaged
under steady speed or low acceleration.
3(Third)
This shift mode limits the gear transmission to the first three gears
or sometimes locks the transmission in the third gear however if the
maximum(Revolution Per Minute) RPM is reached it can cause engine damage
so its recommended for truck towing
2(second)
2 mode limits transmission to the first two gear or locks transmission
in the second gear,its common on cars like ford,kia,and Honda models.Its
recommended for snow/ice driving and climbing or descending a hill
1(first)
This mode locks the transmission in the first gear only in older model
it will not change from 1 automatically except you shift manually while
in newer vehicles it automatically shift out of 1 if a certain RPM is
reached to prevent engine damage
D5
This mode is equipped with auto 5 forward gear ratio and it uses all the
5 gears ratio.The mode D5 is commonly use for highway driving and found
majorly in Honda and Acuras
D4
D4 uses 4 gear ratio that is it uses the first four gear ratios its also in Honda and Acura commonly use for city driving
D3
Uses only the first three gear ratios,its commonly found in
Honda,Acura,VW and pontiac with 4 speed auto it can also be use for city
driving where the traffic is not too light
D2 and D1
Uses the first two transmission gears in this mode D2 the car start in
D2 and up shift to the third gear ratio and its commonly found in older
ford transmission
S(Sport)
Its a similar mode to Drive but the up shift changes much higher up the
engine revolution range,this is maximizing the available engine output
to enhance the performance of the vehicle due to this effect the S mode
consumes more fuel than D mode.
+,- and M
Manual mode selection of gears in certain automatic transmissions such
as Porsche`s Tiptronic and Honda Steptronic and few other products with
Tronic features,some don't have the M mode but have the + and - the
driver can shift by toggling the mounted console shift
W(Winter)
This mode engage the second gear instead of the first gear when pulling
away from stationery to reduce the likelihood of loss of traction due to
wheel spin on ice or snow this is similar to function D2 on GMs,kia,
and Honda automatics,it can be access by moving gear shifter to mode D2
to start,then taking your foot off the accelerator while selecting D
once the car is moving.The W mode is found in some Volvo,Mercedes
Benz,BMW and GMs of European model
B(Brake)
B is a mode selectable on some Toyota model in non-hybrid cars,this
mode let the engine do compression braking also known as engine braking
typically when encountering a steep hill,it has the same effect in
slowing car without using brakes.
عنوان: کتاب صوتي سرزمین کورها
نویسنده: هربرت جرج ویلز
مترجم: مصطفی امینی
زمان کل: 1 ساعت و 20 دقیقه
زبان: فارسی
نوع فایل: MP3
راوی: بابک 
توضیحات:
