24-01-2013, 04:50 PM
AUTOMATIC RAIN OPERATED WIPER AND HEAD LIGHT DIM & BRIGHT CONTROLLER
[attachment=48373]
INTRODUCTION
A wiper generally consists of an arm, pivoting at one end and with a long rubber blade attached to the other. The blade is swung back and forth over the glass, pushing water from its surface. The speed is normally adjustable, with several continuous speeds and often one or more "intermittent" settings. Most automobiles use two synchronized radial type arms, while many commercial vehicles use one or more pantograph arms. Mercedes-Benz pioneered a system called the Monoblade in which a single wiper extends outward to get closer to the top corners, and pulls in at the ends and middle of the stroke, sweeping out a somewhat 'W'-shaped path. Some larger cars are equipped with "hidden" (or "depressed-park") wipers. When wipers are switched off, a "parking" mechanism or circuit moves the wipers to the lower extreme of the wiped area, near the bottom of the windscreen, but still in sight. To hide the wipers, the windscreen extends below the rear edge of the hood, and the wipers park themselves below the wiping range at the bottom of the windscreen, but out of sight.
WIPER
The fi¬rst windshield wipers were operated manually by moving a lever inside the car back an¬d forth. Today, most of us take our electric windshield wipers for granted. The wipers faithfully keep the window clear, moving back and forth across the windshield countless times as they sweep the water away. On their highest speed, they move impressively fast, sometimes shaking the car from side to side. Windshield wipers are found on car windshields, some car headlights, and airplanes and even on the space shuttle. In this article, we'll take a look inside windshield wipers, learn about the blades and the controls and then explore a new rain-sensing wiper control system.
INSIDE THE WIPERS
The wipers combine two mechanical technologies to perform their task:
A combination electric motor and worm gear reduction provides power to the wipers.
A neat linkage converts the rotational output of the motor into the back-and-forth motion of the wipers.
In the past, automakers have tried to either eliminate the wipers or to control their speed automatically. Some of the schemes involved detecting the vibrations caused by individual raindrops hitting the windshield, applying special coatings that did not allow drops to form, or even ultrasonically vibrating the windshield to break up the droplets so they don't need to be wiped at all. But these systems were plagued by problems and either never made it to production or was quickly axed because they annoyed more drivers than they pleased.
BATTERY
Battery is use for storing the energy produced from the solar power. The battery used is a lead-acid type and has a capacity of 12v; 2.5A.the most inexpensive secondary cell is the lead acid cell and is widely used for commercial purposes. A lead acid cell when ready for use contains two plates immersed in a dilute sulphuric acid (H2SO4) of specific gravity about 1.28.the positive plate (anode) is of
Lead –peroxide (PbO2) which has chocolate brown colour and the negative plate (cathode) is lead (Pb) which is of grey colour.
When the cell supplies current to a load (discharging), the chemical action that takes place forms lead sulphate (PbSO4) on both the plates with water being formed in the electrolyte. After a certain amount of energy has been withdrawn from the cell,both plates are
Transformed into the same material and the specific gravity of the electrolyte (H2so4) is lowerd.the cell is then said to be discharged.there are several methods to ascertain whether the cell is discharged or not.
BATTERY CIRCUIT DIAGRAM DETAILS:
In our project we are using secondary type battery. It is rechargeable Type. A battery is one or more electrochemical cells, which store chemical energy and make it available as electric current. There are two types of batteries, primary (disposable) and secondary (rechargeable), both of which convert chemical energy to electrical energy. Primary batteries can only be used once because they use up their chemicals in an irreversible reaction. Secondary batteries can be recharged because the chemical reactions they use are reversible; they are recharged by running a charging current through the battery, but in the opposite direction of the discharge current. Secondary, also called rechargeable batteries can be charged and discharged many times before wearing out. After wearing out some batteries can be recycled.
DC MOTOR:
The d.c generators and d.c motors have the same general construction. When the machine is being assembled, the workmen usually do not know whether it is a d.c generator or motor.any d.c.generator can be run as a d.c.motor and vice versa. All d.c.machines have five principal components viz(i)Field system (II) armature core (iii) armature winding (iv)Commutator (v) brushes
(i) FIELD SYSTEM:
the function of the field system is to produce Uniform field within which the armature rotates.it consists of a number of salient poles(of course, even number) bolted to the inside of circular frame (generally called yoke).the yoke is usually made of solid cast steel whereas the pole piece are composed of stacked laminations. Field coils are mounted on the poles and carry the d.c exciting current. The field coils are connected in such a way that adjacent poles have opposite polarity.The m.m.f. developed by the coils produces a magnetic flux that passes through the pole pieces,the air gap,the armature and the frame.practical d.c machines have air gaps ranging from 0.5mm to 1.5mm.since armature and field systems are composed of materials that have permeability,most of the m.m.f.of field coils is required to set up flux in the air gap.by reducing the length of air gap,we can reduce the size of field coils(number of turns).
(ii) ARMATURE CORE:
The armature core is keyed to the machine shaft and rotates between the field poles. It consists of slotted soft-iron laminations (about 0.4 to 0.6mm thick) that are stacked to form a cylindrical core. The laminations are individually coated with a thin insulating film so that they do not come in electrical contact with each other.the purpose of laminating the core is to reduce the eddy current loss.the laminations are slotted to accommodate and provide mechanical security to the armature winding and to give shorter air gap for the flux to cross between the pole face and the armature “teeth”.
(iii) ARMATURE WINDING:
The slots of the armature core hold conductors that are connected in a suitable manner.this is known as armature winding. This is the winding in which “working”e.m.f. is induced.the
The armature conductors are connected inseries-parallel: the conductors being connected in series so as to increase the voltage and in parallel paths so as to increase the current. The armature winding of a d.c.machine is a closed –circuit winding: the conductors being connected in a symmetrical manner forming a closed loop or series of closed loops.
(iv) COMMUTATOR;
a commutator is a mechanical rectifier which converts the alternating voltage generated in the armature winding into direct voltage across the brushes.the commutator is made of copper segments insulated from each other by mica sheets and mounted on the shaft of the machine. The armature conductors are soldered to the commutator segments in a suitable manner to give rise to the armature winding.depending upon the manner in which the armature conductors are connected to the commutator segments ,there are tow types of armature winding in a.d.c. machine viz(a) lap winding (b) wave winding.Great care is taken in building the commutator because any eccentricity will cause the brushes to bounce, producing unacceptable sparking .the sparks may burn the brushes and overheat and carbonize the commutator.
[attachment=48373]
INTRODUCTION
A wiper generally consists of an arm, pivoting at one end and with a long rubber blade attached to the other. The blade is swung back and forth over the glass, pushing water from its surface. The speed is normally adjustable, with several continuous speeds and often one or more "intermittent" settings. Most automobiles use two synchronized radial type arms, while many commercial vehicles use one or more pantograph arms. Mercedes-Benz pioneered a system called the Monoblade in which a single wiper extends outward to get closer to the top corners, and pulls in at the ends and middle of the stroke, sweeping out a somewhat 'W'-shaped path. Some larger cars are equipped with "hidden" (or "depressed-park") wipers. When wipers are switched off, a "parking" mechanism or circuit moves the wipers to the lower extreme of the wiped area, near the bottom of the windscreen, but still in sight. To hide the wipers, the windscreen extends below the rear edge of the hood, and the wipers park themselves below the wiping range at the bottom of the windscreen, but out of sight.
WIPER
The fi¬rst windshield wipers were operated manually by moving a lever inside the car back an¬d forth. Today, most of us take our electric windshield wipers for granted. The wipers faithfully keep the window clear, moving back and forth across the windshield countless times as they sweep the water away. On their highest speed, they move impressively fast, sometimes shaking the car from side to side. Windshield wipers are found on car windshields, some car headlights, and airplanes and even on the space shuttle. In this article, we'll take a look inside windshield wipers, learn about the blades and the controls and then explore a new rain-sensing wiper control system.
INSIDE THE WIPERS
The wipers combine two mechanical technologies to perform their task:
A combination electric motor and worm gear reduction provides power to the wipers.
A neat linkage converts the rotational output of the motor into the back-and-forth motion of the wipers.
In the past, automakers have tried to either eliminate the wipers or to control their speed automatically. Some of the schemes involved detecting the vibrations caused by individual raindrops hitting the windshield, applying special coatings that did not allow drops to form, or even ultrasonically vibrating the windshield to break up the droplets so they don't need to be wiped at all. But these systems were plagued by problems and either never made it to production or was quickly axed because they annoyed more drivers than they pleased.
BATTERY
Battery is use for storing the energy produced from the solar power. The battery used is a lead-acid type and has a capacity of 12v; 2.5A.the most inexpensive secondary cell is the lead acid cell and is widely used for commercial purposes. A lead acid cell when ready for use contains two plates immersed in a dilute sulphuric acid (H2SO4) of specific gravity about 1.28.the positive plate (anode) is of
Lead –peroxide (PbO2) which has chocolate brown colour and the negative plate (cathode) is lead (Pb) which is of grey colour.
When the cell supplies current to a load (discharging), the chemical action that takes place forms lead sulphate (PbSO4) on both the plates with water being formed in the electrolyte. After a certain amount of energy has been withdrawn from the cell,both plates are
Transformed into the same material and the specific gravity of the electrolyte (H2so4) is lowerd.the cell is then said to be discharged.there are several methods to ascertain whether the cell is discharged or not.
BATTERY CIRCUIT DIAGRAM DETAILS:
In our project we are using secondary type battery. It is rechargeable Type. A battery is one or more electrochemical cells, which store chemical energy and make it available as electric current. There are two types of batteries, primary (disposable) and secondary (rechargeable), both of which convert chemical energy to electrical energy. Primary batteries can only be used once because they use up their chemicals in an irreversible reaction. Secondary batteries can be recharged because the chemical reactions they use are reversible; they are recharged by running a charging current through the battery, but in the opposite direction of the discharge current. Secondary, also called rechargeable batteries can be charged and discharged many times before wearing out. After wearing out some batteries can be recycled.
DC MOTOR:
The d.c generators and d.c motors have the same general construction. When the machine is being assembled, the workmen usually do not know whether it is a d.c generator or motor.any d.c.generator can be run as a d.c.motor and vice versa. All d.c.machines have five principal components viz(i)Field system (II) armature core (iii) armature winding (iv)Commutator (v) brushes
(i) FIELD SYSTEM:
the function of the field system is to produce Uniform field within which the armature rotates.it consists of a number of salient poles(of course, even number) bolted to the inside of circular frame (generally called yoke).the yoke is usually made of solid cast steel whereas the pole piece are composed of stacked laminations. Field coils are mounted on the poles and carry the d.c exciting current. The field coils are connected in such a way that adjacent poles have opposite polarity.The m.m.f. developed by the coils produces a magnetic flux that passes through the pole pieces,the air gap,the armature and the frame.practical d.c machines have air gaps ranging from 0.5mm to 1.5mm.since armature and field systems are composed of materials that have permeability,most of the m.m.f.of field coils is required to set up flux in the air gap.by reducing the length of air gap,we can reduce the size of field coils(number of turns).
(ii) ARMATURE CORE:
The armature core is keyed to the machine shaft and rotates between the field poles. It consists of slotted soft-iron laminations (about 0.4 to 0.6mm thick) that are stacked to form a cylindrical core. The laminations are individually coated with a thin insulating film so that they do not come in electrical contact with each other.the purpose of laminating the core is to reduce the eddy current loss.the laminations are slotted to accommodate and provide mechanical security to the armature winding and to give shorter air gap for the flux to cross between the pole face and the armature “teeth”.
(iii) ARMATURE WINDING:
The slots of the armature core hold conductors that are connected in a suitable manner.this is known as armature winding. This is the winding in which “working”e.m.f. is induced.the
The armature conductors are connected inseries-parallel: the conductors being connected in series so as to increase the voltage and in parallel paths so as to increase the current. The armature winding of a d.c.machine is a closed –circuit winding: the conductors being connected in a symmetrical manner forming a closed loop or series of closed loops.
(iv) COMMUTATOR;
a commutator is a mechanical rectifier which converts the alternating voltage generated in the armature winding into direct voltage across the brushes.the commutator is made of copper segments insulated from each other by mica sheets and mounted on the shaft of the machine. The armature conductors are soldered to the commutator segments in a suitable manner to give rise to the armature winding.depending upon the manner in which the armature conductors are connected to the commutator segments ,there are tow types of armature winding in a.d.c. machine viz(a) lap winding (b) wave winding.Great care is taken in building the commutator because any eccentricity will cause the brushes to bounce, producing unacceptable sparking .the sparks may burn the brushes and overheat and carbonize the commutator.