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weirdo a but that similar treatment
click day the simple boards
bar complicated electronic device in a missile they call the grand mama papa
bunch in a number of hitting the electrical equipment
some types of mothers and generators are probably in years
alternating current or if they see and direct current or d_c_ motors and generators
this film will show the principles governing the operation of dec motors
and generators basic to the understanding of d_c_ mothers
and generators is a simple generation of an electoral on
divorce and a_t_m_ apt
mechanical energy removing of all why are all conductor across
a magnetic field by hand in this instance
produces electrical energy magnetic field is composed of lines of force
as the conductor cuts these lines an electro motherboards or cmf is generated
in the conductors moving the conduct of down through the field
makes them even though they told me to deflect one-way
which means the end that has one direction moving the conductor up through the field
produces the opposite deflection of the needle the m_f_n_ is now changed direction
moving the conductor back and forth with the field
does not make the middle of the hold me to deflect
there is no d_m_s_ because the conductor is not cutting the field
to illustrate the direction of current flow but conventional symbols will be used
current flowing in a conductor away from us is represented by across
toward us viaduct however moving a conductor in an automobile
demonstrate reciprocal fashion
is all quite an impractical assembled generator other e_m_s_ can also
be made by rotating a single time call
within a stationary magnetic field of two magnets with opposite polarity
right now in effect becomes too conductors
because both a top and bottom sections cut magnetic lines during rotation
since they cut lines of course a lot opposite directions as they were ok
here i met some opposite polarity will be generated in the conductors
in our dr cohn flow in the circuit polarities of the two conductors
must be opposite the amount of m_s_ generated at any instant
is determined by three factors the strength of a magnetic field
that is the number of lines of course the length of the conductor cutting the lines
of course and the velocite with which the conductor
is turning we can determine the amount of instantaneous
imap by a simple formula
the instantaneous cmf fees equals
busy the strength of the field
times l the length of the conductor cutting lines
of force times leave the velocity of the conductor
and increase in the number of lines of course all the strength of the field
increases the instantaneous m_f_n_ the conductor increases in the length of the conductor cutting
lyons also increases the e_m_s_
and finally the greater the velocity of the conductor
the greater the e_m_s_ this formula assumes conductor motion in a
straight line that has to say
cutting the same number of lines for each increments of its motion
but the conductor in an actual machine is not moving in a straight line but rotating
when the conductor moves in a rotary path remember the blinds cuts varies
depending on the position of the conductors at the top of the field for instance
no lines are being cut and all of the americans generated
as the conducted keeps turning the number of lions cut increases
so that adequate time or ninety degrees well maximum numbers being cut
and maximum geometries generated again at one hundred eighty degrees
no lines are cut nolte m_s_f_
we reach a maximum again at two hundred seventy degrees
and finally again that three hundred sixty degrees no lines are cut
the conductor has rotated three hundred sixty mechanical did raise
which correspond in this instance three hundred sixty electrical degrees
therefore want to conduct a rosemarie path another factor is added to the original formula
for the determination of instantaneous cmf
formula that now applies instantaneous idiomatic
equals field strength times the length of the conductor
times velocity multiplied by sign plato
finger is the angle formed by the flux line on the motion of the conductor
one member of the winds cut them the amount of d_n_a_ degenerated
is proportional to the side of the angle form by the magnetic lines with a
conductor motion autograph of the a m f versus conductor position
during one revolution will be assigned way of representing alternating
current or nec or moderate generators
produce a_b_c_ internally what you have seen so far
israeli pavilion operation of a basic a_b_c_ generator
but our purpose was to explain the principles of operation of a d_c_
generators the death of my current
we will attach each end of the conductor to a segment of copper
forming a commutative now our machine is a d_c_ generated
but commentator rotates with the move stationary contacts carbon brushes
right on the commutator segments they provide a means of collecting a meteor
or any other loan to the generators
republican dr while novel rotors and the commutator are
referred to as the armature as a liberal dolls
and the m_f_n_ the conductor reverses polarity connections to the low dollar also waivers
and the current or maintain the same direction externally
represented graphically the ultra amplitude still there is
or do you see is a more formal pulses ezell pulsating direct current
or p_v_c_ local station from zero to a maximum
twice for each revolution of the loop is called rebel
this rebel can be reduced by adding more lopes
and more commutator segments of the existing armature
tour groups at right angles connected to poor commentator segments
provide to outputs instead of one these outputs are ninety degrees displaced
or part which combine to smooth the d_c_ outpost
however even with troops and for commutator segments
the rectified curve is still somewhat irregular by adding magnets
we increase the number of deals cut by the armature
as we increase the number of milton commutator segments
variation between maximum and minimum value decreases
this in effect tends to flatten the d_c_ outpost
practical d_c_ generator are mergers have a great many loops while marauder
will feel is composed of many electro magnets together these factors tend to create an almost
pure dcr fought an important problem in the design of generators
is the prevention of sparking between the commentators
and the brush assembly the prevention of sparking depends on the
position of the brushes this swine flu points of zero generated ear
and i have is called
bunyan proclaim placing the brushes in this new complain
reduces the tendency for sparking between brushes and commentator
because during the time a brush is touching both commutator segments
there was no difference in potential between these segments
theoretically no sparking should occur at the commutator
brushes when they are placed in this position
but the current flowing in the armature loops or coils
sets up a magnetic field of its all this magnetic field interacts with the main
magnetic field and distorted well distortion causes a shift in the new
complain and sparking at the brushes
the effect is called armature reaction sparking may cause severe interference in
nearby electronic equipment there are two ways of maintaining the new
complain in its correct position
alamos avoiding sparking it may be done by the adjustment of the brush
position the bushes are adjusted to volume readjusted
neutral plan the other way of maintaining the new complain
is by adding enter bolster the generator field these are the polls are small magnets place
between the goals of the main field magnets
they end up all fields of all the fields created by armature reaction
run into a plane has moved back toward the correct position
in addition to brother contract armature reaction windings
called compensating landings i sometimes plays demanding bulldozers
let current in these windings is armature current
flowing in opposite direction to the current in the armature conductors
magnetic fields in bc generators may be produced by electro magnets or permanent
magnets permanent magnets are used in relatively small
devices like appeal telephone ringing generators
in larger generators lapierre was created by electro magnets
bloomfield winding used in this d_c_ generator can be represented by a symbol
well as simple as that of an iron core inductors i want to excite the field windings
can be supplied from an external source in that case
the generator is classified as separately excited
a small part of the generators all-out blood can also do the exciting
in that case it will be ourself excited generators
celtic cited generators must be initially magnetized
the residual magnetism and the court of appeal widening
provides enough magnetism to begin generator actions
looking coil winding may be connected in several ways
this is a series while generator which means that the iroquois listen series
with the armature because of his series arrangement
it as poor voltage regulation the reason for this can be demonstrated in
the following matter additional road will cause more current to
flow in the field co increase infield strength
increases voltage increase in voltage causes more current of
all this continuing action
stops only when the court is saturated when the loan has increased
voltage will increase when the love decreases
voltage will be grapes voltage regulation in the series while generator
therefore is very poor
when instead of in series will be arriving as connected in parallel
with the armature of the world we have a shop while generators
now buckingham current is independent alone current
therefore an increase in armature current will not cause an increase in the voltage
output voltage regulation here is greatly improve
insurance while generators therefore changing world cause is relatively small change
in boulder job board by changing the armature winding
our compound while generator results which combines the best features of both types
was susannah shaw ground generators when windings are arranged
so that magnetic field oppose each other it becomes in effect a series generators
business use only by a constant current is the prime requirement such as in arc
welding by changing the magnetic polarity of one of
the fields will feel windings aid one another
as a result this compound while generator has grown baldridge
unfair conflagration a graphic representation of generator output
characteristics with terminal voltage plotted vertical a
and armature current horizontally would look something like this
as we have seen in the output of assumes while generator
voltage regulation is very poor in parallel or shop while generators
low voltage regulation is fairly good but current regulation in sports
compound while generators all-pro flat compound it up with that is normally
most desirable it combines the good features of both bush
and ensues while generators and provides stable voltage upward under changing
worlds as we have seen in our analysis of the d_c_
generator its primary function as the conversion of
mechanical energy to electrical energy
if we now reverse the procedure and connect them electrical power source to
the generator we have a dec motor instead of a d_c_ generator
morrow action can be illustrated by attaching apollo soyuz to a conductor
which is inside a magnetic field the electric current creates polarity and
the conductor will solve all of a magnet
attracts them off all the conductor and reply all the south pole
well multipole of a magnet attract herself all of a conductor
and rebels the north pole this creates movement
depending on the direction of the study magnetic field
movement to also depends on the direction of the current although the
wire by changing the polarity of the battery
the conductor now holds in the opposite direction to see what really happens
let's go to a growing again here are conductor was suspended in a magnetic
field cohen fall from a policy was created to all
magnetic field and run around the conductor
this fielder while the conductor reacts with them a magnetic field to cause
motion of a conductor either olive oil field all into it
the arrow point indicates the direction of the current flow in the conducted
in this case the flow is taught us looking over the conductor has the same direction
as the main field above the conductor family opposite direction of the field biloba
conductors these two magnetic forces added together
distort the lines of the main field upward mobile above the conductor is that's made
stronger an appeal be lowered the conductor is made weaker
so the conductor moves down conversely when con flows in the opposite
direction that is to say away from us
will feel that the conductor opposes the main field above the conductor
those aids the main field below the conductor distorting the lions down
will be will be loyal to conduct a reverse made stronger
while the field above the conductor is made relatively weaker
those forces the conductor to move off with this basic principle of our action on
the story we got our exam and the d_c_ motors
verbally cdc walter like the d_c_ generator consists of a paleomagnetic polls
an armature made up of a single terminal commutator
and the brush assembly as we have seen
a conductor in a magnetic field will move one of old which is applied to it
with a voltage applied and the magnetic field and control has shown
alright conductor will be pushed down while the last one
is pushed off sinful forces on each conductor are now in
exact balanced there will be no more motion
adding an envelope and to commutator segments insures that had no time
well a balancing force is cancel each other out
within set up there will be motion that all times
as one commutator segment is moved away from the brushes
and other now takes his place and the movement continues
the greater the number of loops in the armature smoother its motion
all this reason rotors and practical bc motors have many whoops
since collor de mello groups must reverse each up cycle
to comitatus aikman's profile required here in the locker as in the d_c_ generators
there was a neutral plan they enjoy action of a conductor fields on
the main field cause of this new proprietorship and starting
to occur when the loan is added sparking n_b_c_ motors also produces bird
commentators and if there is a nearby electronica grappled
this parking can be prevented in one of two ways
one is by the adjustment of the brush position the branches are moved until daylight army
adjusted new complaint in the motor as in the generator
small interposed between the both of the main magnets are also used to eliminate
the shift of the neutral plan these into polo fields
tend to oppose the fields created by armature reaction
one hundred-point has moved back toward its correct position
also aiding are compensated windings which carry armature current emi opposite
direction to the current of the armature conductors
but neutral plane has less maintained in its proper position
do see motors operate most efficiently when stalking is a laminated
we start earlier but when a conductor was moved by mechanical
energy and a magnetic field aguilar map is generated
this is a generator action in the d_c_ motor
one rotation as desired is necessary to apply a medium after the conductor
however when used as a motor an opposing cmf is also generated in the conductor
this is called the contour electoral reforms or a c_ e_ and a half
by lenses lol the generated c_e_o_ math
must oppose the applied idiomatic the amount of c_e_o_ math depends on the speed
of rotation this is a practical importance in large motors
one starting large motors the problem exists of limiting current through the
rubble windings until a c_e_o_ now can be built up
if the phone card is applied before the c_e_o_ method i loves
it may burn out the rotor windings starting boxes are used with the e_c_ motors
in order to avoid his application of colon before the c_e_o_ map is build-up
here is a basic shunt motorways starring box in a starting position
basilica to the rotor windings is closed through a series of lies resistance calls
as the level of us which is moved roller speed and c_e_o_ math build up gradually
and the resistance corals are subsequently caught out
until running speed has been reached level is held in the fully open position by
an electro magnet if for any reason the power should fail
although field coil from the electromagnetic comes the energized
and the lever is returned to the starting position
by spring action just as in d_c_ generators
dec motors seldom use prominent magnets for the people
instead electro magnets are used like with the d_c_ generator feel why things
are constructed in several ways each type of landing a special characteristics
special values and specific uses groceries while motor has good starting talk
or turning force talked offends on armature current
and on the field strength stansfield strength is proportional to column
rahein starting current before c_e_o_ methods developed
all thanks to our as the square other columns promoter begins to turn
attempting to develop enough c_e_o_ math to completely opposed the applied p_m_s_
the loan program slips acting to control the speed of the motors
but if below is suddenly removed like in a case of a broken belt
promoter will build up speed trying to develop more c_e_o_ math
until it destroys itself beauchamp while motor has less starting park
but it is less dependent on law enforcement control
emissions while motor well beyond coils are connected in parallel
directly across the d_c_ input terminals was starting torque is not as great as in
the series motor stansfield strength is not affected by armature
current low-speed overshot boulder
is fairly constant under conditions of changing world
as more was applied the speed of the armature decreases
this decreases the c_e_o_ math and increases the current invoice
the increase income earned in blood belongs to the coupling between the field
of armature and increases the talks
causing a lot of the resume approximate running speed
a sudden reduction unload well not damage the mother
because the field code is independent of roller current in the shampoo isle motor
the desirable characteristics of both of suzan shown blog motors
can be achieved in the compound while motor in order to obtain good starting point
the city's fingers used when running speed has been obtained
a center of the girls which cuts out the sewage field
and cuts emoticon failed is now a shunt motor
and the speed regulation is good compounding provides good starting point
and godspeed regulation those allows for efficient operation analyzes
the possibility of damage to the moderate
now for a quick summary they operation of although getting electrical
machinery is based on one simple principle
but generation of an d_m_s_ the principle is used in the construction
of a simple casey generator but generally there are four
the or instantaneously and a half
equals b strength the field
times l length of the conductor
times be velocity of the conductor but because the movement of a conductor in
the field of actually circular we must also multiply with a sign of the angle
formed by the lines of forest and motion of the conductor
in order to arrive at the e_m_s_ all generators are basically alternating current
generators and produces nec internally
the basic a_b_c_ generator becomes a d_c_ generator when a commentator is
attached to the conductor each comitatus segment rotates with its respective
conductor producing a direct current
those columns which is a pulsating khatam is made smoldered by the addition of moral
magnets send more troops sparking in a generator
is sometimes caused by a shift in the neutral plan
this can be corrected by adjusting the brush position
or by the use of and the polls and compensating windings
and full field windings may be supplied from a outside source
in which case the generator will be separately excited
all the current may be a part of the generators all out for it
in which event it is called self excited generator feel why things are constructed
in three ways ceo islam
whether field windings on the armature are in series
sean globs in which the field winding is in parallel
with the average around the world and compound wild and wish that those features
of both bush and dan series while generators
are combined voltage regulation in the series while generator
is poorer image and while generator voltage regulation
is fairly good but current regulation is four
compound while generators provide stable voltage under changing world
this output is normally most desirable manuel action is the opposite of generator
procedure in a d_c_ motor
voltage is applied to to a halt loops in a magnetic field
this causes polarity envelopes the interaction of this pull out a date with
the polarity of the field makes the loops rotate
this is the basic dec motor when the conductor of the motor is rotated
by an applied here and a half it also generates avocado electro motive force
are going to lenses loft this generated cd and i have
must oppose be applied cmf as in generators
field windings in d_c_ motors are three types the series while motor has good starting talks
but since it's always governing factor is the load
the speed regulation is poor if the lotus disengage suddenly
the local race to destruction incham wild motors
with the field coils connected in parallel across the d_c_ input terminals
the starting park is not too good but since the field current is independent
of the rotor current was speed regulation is quite good
the compound while motor combines the best features of both types
it uses a series section for good starting talks
limit switches to a shunt arrangement for good speed regulation
vcd electrical motors and generators are at the heart of much military
barbara understanding of and use their board important
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