mec human sensing and following trolley

7/22/2019 MEC Human Sensing and Following Trolley

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MEC, mechanical. Hassan.

Mr Abhishek Iyer

[email protected]

Corp Rs 1000 on 160911.

1. Telescopic conveyor.(which can be extended for length as required).12K---

2. Flexible conveyor.12K/15K------

3. Hydraulic tube bending machine.---16K-- This is a hydraulic machine to bend the metal tube upto 16mm diameter. The metal tubebending needs tremendous force which is done manually now. Here in this case we are making the hydraulic pump, cylinder and tank

within one housing and mounting the punch on the ram and fixing the dies on the frame within which the metal tube is inserted and by

the lever operating the pump, the ram comes out bending the tube to the required radius and angle. The force input on the lever isapproximately 10kg and at the output ram we get atleast 1500kg

4. Design and fabrication of wind powered apparatus to run the automobile..16K---- .--- this is a electric vehicle being driven by themotor and backed by Dc batteries and the batteries get self charged during the drive of the vehicle at the highways at high speed by

wind turbines fixed at the front portion of the vehicle. The position of the wind turbines are as shown in the below figure. The point 18

is the place where wind turbines will be fixed. The assembly will be made in such a way that it is detachable.

5. Hydraulic bench vice, foot pedal operated.-16K-- this project can be used by college permanently as a vice for bench, drilling andsmall machining works)----Hydraulic pressure is used for locking the workpiece which is kept by the hand positioned properly. This

smoothens the work and efficiency. In this the bench v ice is operated by the hydraulic cylinder and is operated by the foot pedal

pumping which is connected by the hose connection. A fabricated frame on which, Fixed jaw is fixed to the body which is having theguide railing to guide the movable jaw to move towards and away the fixed jaw for clamping and de-clamping. The hydraulic cylinder

is fixed behind the moving jaw and the ram is moving in between. The cylinder is connected by the hose connection to the foot

operated pump. The release valve is provided at the foot pump through which the fluid returns back to the fluid chamber. Fluidchamber is provided with the pump housing.

6. Hydraulic motor from linear to rotary providing the constant torque.15K--- in this the hydraulic pump operated by the lever is

creating the oil pressure which is connected to the actuator or motor which is driven whenever required by releasing this

accumulated pressure. We can use this drive to run any machine where we are not using any source of external power.

7. Automatic shaft loading system on machine.15K-- this is a machine working through a motorized rotation and lifting the shafts fromthe hopper stage wise to reach the machine chuck one after the other. This action is continuous to feed the machine and the speed can

be set according to the machine requirement. This involves cranking, lifting and stacking mechanism working automatically8. Steps locking ladder.12K-----This is single pole with the locking mechanism for the steps with leg foot holders and the lift slide

mechanism for stepping up stage wise. This is compact with a single center pole and the base stand and person standing on the footholder will lift up the steps left locking that in position will lift the right and again locking that in position will lift the left foot thereby

positioning in the elevated height.

9. Automated belt conveyor with number counting and sorting10. Vertical carousel storage system

11. Foot walking mobile phone charging.
mailto:[email protected]:[email protected]:[email protected]


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12. Self reliant power generation by footstep and door opening/closing action generating air pressure converting electricity by m icro

turbine.-----15K- -----the normal action of the footstep and the door opening closing of the commercial places where hundreds of

people operate daily, the actions pumping the air into the tank which can be whenever required can be used to run the micro

turbine to generate the electricity to charge the battery and drive the CFL tube. Such small units if installed in each and every

commercial shops and public offices, the actions can store good air pressure to generate power whenever required.

13. Electrical power generation system using Railway track.

14. Braking force retention in any machine to generate electric power.---15K----15. Braking force retention in automobile for immediate drive after release.15K---- in this we are making a small working model which

is powered by DC motor and when brake is applied, shown by hand lever engaging in this model, the spring retention takes place,

which is locked and when we release the brake for drive further, we dont put more power, the vehicle will start by the spring retendedforce for the immediate drive. Normally we put first gear in actual vehicle to have the starting torque which is eating more fuel, here in

which case we will use the brake force retended for immediate drive of the vehicle thus saving fuel.

16. Free energy by antigravity rotations.---16K--- in this we are making the ring assembly to rotate along a center which is holding

masses which are pivoted on this ring in the offset center to effect the gravitational effect to continue the rotations. We are

powering the center axle by the motor momentarily and make it to stop and the masses will roll around to continue the rotation due

to the antigravity effect, generating the power continuously. The power spent to rotate is very less than the power generated. (ratio

of power generated is 1:2.5)

17. Energy absorbing bumpers activated by sensing prior to colliding.

18. Wheel chair cum bed.---17K----it is a transport chair and emergency evacuation carrier designed for use for persons with lowerextremity, mobility or severe physical disabilities or spinal cord injury, providing infinite positioning seat.

19. Design and fabrication of any side moving trolley for material handling.16K--- this is a trolley with four wheels being controlledfor the drive for material handling. When required to be driven in lateral direction, we activate a button to rotate wheels in angular turn

for 90 degree slide or any degree slide. The tilting of all wheels in angle is effected by the cam and link mechanism being powered by

DC motor.

20. Wheel chair cum bed.---15K----it is a transport chair and emergency evacuation carrier designed for use for persons with lower

extremity, mobility or severe physical disabilities or spinal cord injury, providing infinite positioning seat.

21. Power generation using suspension cushioning---14K.----Normally in the automobiles, the alternator dynamo is being driven by the

engine by the belt being clubbed to the engine which is reducing the efficiency of the engine. If it is removed and power is generated

by suspension cushioning, which is not utilised till now, the engine efficiency is going to the increased. The suspension cushioning is

converted into rotary by the set of gear trains which drives the DC dynamo to generate power which charges the batteries.

22. Automatic length inspecting and sorting station.----15K----the work piece coming on the gravity conveyor will stop at the stage and

the length is inspected by the sensors and if not to the parameter set, the base will automatically tilt to drop the rejected work-piece

to the rejection bin and if the length is as per the requirement will make the piece to move ahead. No manual intervention. We are

using round piece in this model.

23. Automatic loading station to the various vehicles, rotary, label sensing according to the destination.15K--- In this parcels are

moving on the rotary base. The parcels are labeled by the magnetic strip which is sensed at the entrance point and the rotary base is

having two set of outlets which are marked as destination point below which lorries are parked of that destination. When the

parcels of the particular destination is sensed, and when that parcel comes near the outlet point of the destination, the door

automatically opens to make the parcels get loaded on the vehicle automatically without manual intervention. This is done by the

control circuit. Two number of destinations can be planned in this project.

24. Human sensing and following trolley for material handling----15K----This is a material handling trolley, is

activated by showing the tag and the name of the person is spelled which is recorded by the trolley and

the tag is sticked to the person pant which is sensed by the trolley and the trolley will follow the person. If

he stops, it will also stop and if he moves and turns, the trolley will also turn and if the person is out of its

vicinity, will call the person by the name and when the person is sensed within the vicinity will continue to

follow. The trolley will have drive and steering mechanism, a three wheel base and the control circuit to

operate automatically.25. Passenger alighting system from moving trains.--------16K-------In this during the movement the passenger can get down from the

train without stopping the train in every station avoiding the fuel and time wastage. This is a mechanical system which can be

implemented actually.26. Intelligent orientation correction of the parts feeding during robotic assembly-----16K---work-pieces like stud moving on the

robotic feeder for the assembly are to be oriented properly like threading etc, which may be moving the wrong orientation which is

sensed in this while moving on gravity, stops and checks for the threading V notch by the mechanism by micro-switch and if it is

proper, the stopper moves back making the work-piece to move ahead and if the threading is not sensed in the face direction, the

base rotates to 180 degree to correct the orientation and then stopper moves back and the work-piece continue to move ahead for

the assembly

27. Fabrication of night light system for bullock cart using self power---15K.---- in this we are generating power which can be stored inthe battery to power lighting used in fields. This power generation is by clubbing gears to the bullock cart wheel and bullock cart when

moving will generate power and the stored energy can be used for lighting for the bullock while driving or in the fields where currentis at scarce


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28. Solar air cooler----18K---the solar panel is charging the DC batteries which are backing the air cooler blower to work making the air

to pass through the water causing the evaporative cooling. The batteries are dual chargeable by solar panel and AC mains. Human

movement sensing sensor is provided to put the air cooler on automatically when person is sensed near it. This is table top model29. Power generation by suspension cushioning.--15

30. Power generation through revolving door .14K----Door used in shopping malls and offices, are opened frequently by thecustomers when entering in or out which is converted into rotations and enhanced by the gear train to rotate the generator which

generators power which can be stored in the battery and used for lighting. Here in this model we are showing the output by glowingthe set of lights.

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Title of the project-----Human sensing and following trolley.(E-trolley for material handling).

Aim of the project-----

To design and fabricate the trolley held on the chassis.

To design and fabricate the drive and steering mechanism for the trolley.

To design the control circuit to sense the tag to activate to move.

To design the control circuit to move behind the tag and set the drive and steeringaccordingly.

To design the control circuit to maintain the set distance from the person or the tag, tostop when required and to steer according to the persons movement.

To design the control circuit to be in the range of the person and if lost to search till theperson is there within the range of the trolley sensors.

To design the switching off the trolley after use.

Working principle-----------in this we are making a three wheel vehicle with trolley mechanismon top to hold the various type of materials being taken from the various racks in the shopping

mall. The trolley will have the drive and steering mechanism being motorized and is backed by

DC batteries. The IR emitter tag when shown to the trolley will get activated and the tag issticked to the pant and the trolley will sense the tag and starts following the tag i.e., follows the

person. The IR emitter is continuously emitting the signals and the receiver is on the scanner

fixed to the steering mechanism which diverts the direction as per the emitter to drive the trolley

in that direction controlling the direction as per the persons movement. If the person is out of the

way, the scanner scans around to sense and once sensed will move towards the person. If anything comes in between and the person is out of reach, the scanner scans all around and even if

not sensing the person, then the buzzer sounds, so that the person can reach back the trolley and

again take the activation and makes the trolley to follow.

Advantages-----------


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1. Automation of retail shopping facility.2. These are handy and useful to stores where aisle width or storage is confined.3. Helps the customer to be free during the selection of items.4. It is a high-tech touch to the shopping mall increasing comforts to the customer.5. Increasing the comfort of the customer.

Unmanned operation with remote control support today is available for almost all types of new

and existing rail mounted containers. Besides that, most of the benefits could be emphasizing in

reduction of labor cost, high and uniform productivity, integration with terminal planningsystem, etc. Unmanned operation requires sensor systems for target position (TPS), sensors for

load position, control and communication equipment on the trolley and remote consoles for

control signals. To remain fully operational with terminal at all times requires extraordinary

work flows, narrow time schedules and lots of work which do considerably drive up the overall

investment.

Applied automation should consider follows

Reliability/quality breakdowns are costly in automated terminals.

Serviceability, support and diagnostics.

Flexibilitycapability to handle present and future environment, vehicles, containertypes, operation principles etc.

Simplicitynot more equipment than needed.

Safely---present and executed future safety standards. Standardization and experience.

Recent hypes in robotics technologies innovations emphasis on mobility an intelligence,

thus adds on flexibility and efficiency.

Labor cost, equipment cost.

Specification.

Materials used, list of components.

Power used.

Power used in this project---------the trolley is moving on 12VDC motors and is powered by 6VDC, 3.2ah-

--2nos batteries which can be charged by A/c mains plugging. The circuit draws very less current which is

also supplied by these DC batteries.

The tag is having a separate DC batteries of 9volts to power the transmitter.


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Approximate parts with approximate costing-------

1. Rear axle---------------C30 steel, dia20x75mm---2nos--------------Rs 900.

2. Bearing housing------mild steel, dia45x20---------2nos-------------Rs 900.

3. Ball bearing----------standard, ID15/35/10----------2nos------------Rs 400.4. Wheels and fittings---plastic, dia200mm------------2nos------------Rs 300.

5. Front wheel---------plastic, dia 100mm--------------1nos------------Rs 100.

6. Rear wheel fixing plate----mild steel ----------------2nos------------Rs 400.

7. Drive motor-------------------12VDC, 3amps---------1nos-----------Rs 700.

8. Drive axle---------------C30 steel------------------------1nos----------Rs 500

9. Motor holders-----------mild steel, dia 75x20--------2set------------Rs 600.

10.Steering control motor---12VDC, 1amps-------------1nos-----------Rs 700.

11.Steering assembly--------mild steel,dia100x15mm---2nos---------Rs 700.

12.Thrust bearing for steering---standard, dia70x18mm--1nos-----Rs 250.

13.Frame-------------mild steel angle and flat20x3mm----1set-------Rs 1000.

14.Trolley ---------- zinc steel sheet of 1mm thick-----1set------------Rs 800.15.Trolley fixtures------------------mild steel ------------1set------------Rs100.

16.Circuit---------------------------electronic components1set------Rs 4000.

17.Batteries -----------------------6VDC, 3.2ah---------2nos-------------Rs 400.

18.Charger------------------------standard---------------1set-------------Rs 200.

19.Labor charges-------------------------------------------------------------Rs 2500.

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The working can be explained in the more easier way-------

We are having two motors in this project. One motor is for drive and another motor is for steering,

which is fixed to the tilting base itself. This base is rotating for 150 degree in search of the infra red ray

being emitted by the emitter. Once it finds the infra red rays, the steering motor tilting stops instantly

and connects the drive motor to start to move in that direction. If any body comes in between, the

shade is sensed by the light dependant sensor to sense the particular shade which triggers the control

circuit to cut off the supply to the drive motor to stop till the light dependant resistor is sensing the

shade. The same case when the owner is also sensed to stop while following avoiding the hitting to the

person.

Circuits involved------

Tag activation to start the trolley.

Recording the persons name and save it for further usage.

IR emitter and transmitter to control drive and steering.


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LDR circuit for persons sensing and maintaining the distance as preset, to stop the trolley at a

particular distance from the person.

Charging circuit to charge the DC batteries.

Working of the circuit-----------

1. Card activation circuit--------in this we are providing magnet at the card which closes the

normally open reed relay or magnetic sensor which is connected to the pin number 7 of IC-UM-

606 which gives the inverted output at pin number 6 which gives the pulse input to the decade

counter CD-4017 which gives the clock output from pin number 2 which triggers the transistor

to connect the relay to connect the steering motor to start searching for the infra red signals

2. IR Transmitter is fixed on the activation card or tag which is sticked to our pant which will be

emitting signals powered by DC batteries.

3. The IR receiver is connected through the regulating IC to the transistor BC547 to pin number 2

of opto coupler MCT2E which gives the input voltage to pin number 7 of IC-UM-606 which gives

the inverted output to pin number 6 to trigger BC547 to connect the relay to stop the rotating

steering motor in search of the IR transmitted signals and start the drive motor.

4. Voice recording repeat circuit--------The recorder is available in ready market which we have

taken and made the circuit to repeat the recorded voice. In this we have set the variable resistorto the required range and the input voltage at pin number 7 varies which gives the inverted

output at pin number 6 to trigger the transistor BC547 to connect the relay to repeat the

recorded voice relay.

5. LDR Obtrusion sensor circuit-----------The light dependant resistor is fixed at the front face which

senses the shade falling on it. In the absence of light falling due to the obstruction in the path,

the internal resistance of the LDR changes which gives the high state input voltage at pin

number 7 of IC, Um-606 which gives the inverted output at pin number 6 to trigger the

transistor BC547 to connect the relay to stop the drive motor to stop the trolley till the

obstruction is not cleared.

Parts involved------------


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1. REAR AXLE.--------------Round mild steel bar of diameter 24mm is taken for the length of 75mm and

then it is turned on the lathe machine to make steps diameter of 15mm and 12mm to suit the ball

bearing and the wheel and at the end threading is done to lock the wheel with the nut. The wheel

is of plastic with the bore of 12mm. Such two number of axles are made for both the rear wheels.

2. Motor clamp.------ A mild steel flat is taken of size 25mmx5mm for the length of 225mm and it is

bent to the circle to maintain the diameter of 75mm to hold the motor. Same size two number of

motor clamp are made. It is welded at the end and m10 nut is welded on it after drilling on the

circumference.

3. Thrust bearing housing top------This is made in mild steel of diameter 90mm and thickness of

20mm being turned on lathe machine for the diameter 85mm outside and counter diameter of

75mm for the depth of 4mm and faced to maintain the thickness as 12mm with the center hole of

10mm to suit the center axle.

4. Thrust bearing housing bottom--------This is made in mild steel of diameter 90mm and thickness of

20mm being turned on lathe machine for the diameter 85mm outside and counter diameter of

75mm for the depth of 5mm and faced to maintain the thickness as 12mm with the center hole of

20mm to suit the center axle which is rotating.

5. Center axle for the thrust bearing housing (steering)-------- This is made out of C30 steel of

diameter 20mm and length of 55mm being turned on lathe machine and step turned for the

diameter of 10mm for the length of 10mm at one side and 30mm at the other side. Hole of 10mm

size is made at the side of 30mm step turning to accommodate the motor shaft which is of 10mm

diameter. A cross drill of 5mm is drilled on the diameter of 20mm and tapping is done to tighten

the motor shaft to the pin. This center axle is welded to the top thrust bearing housing.

6. Frame-----------------This is made out of mild steel angle of size 20mmx20mmx5mm thick being but

and joined as per the sketch and supports are welded as required.


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DRIVE SYSTEMS

Industrial robots are powered by one of three types of drive systems. These three systems

are:

1. HYDRAULIC DRIVES

This is generally associated with larger robots. This drive provides the robot with greater

speed and strength. The disadvantages of hydraulic drive system are that it typically adds to the

floor space required by the robot. Hydraulic drive systems can be designed to actuate either

rotational joints or linear joints.

ELECTRICAL DRIVES

These systems do not generally provide as much speed or power as hydraulic systems.

However, the accuracy and repeatability of electric drive robots fare usually better.

Consequently, electric robots tend to be smaller, requiring less floor space. DC stepping motors

or DC servo motors actuate electric drive robots. These motors are ideally suited to the

actuation of rotational joints through appropriate drive main and gear systems.

Motors

There are variety of types of motors used in robots, they include dc servomotors, stepper motors

and ac servomotors among these motors we have used dc servomotors. The main components of dc

servomotors are rotor and the stator. Usually, the rotor includes the armature and the commutator

assembly and the stator includes the permanent magnet and bush assembly. When current flows

through the winding of the armature it sets up a magnetic field opposing the field set up by the

magnets. This produces a torque on the rotor. As the rotor rotates, the brush and commutator

assemblies switch the current to the armature so that the field remains opposed to the one set up by

the magnets. In this way the torque produced by the rotor is constant through out the rotation.

Another effect associated with the dc servomotor is the back-emf. The effect of the back emf is to act

as viscous damping for the motor.

There are a variety of motors used in the modern robots, they include DC motors, DC screw-

motors stepper motors and AC screw-motors. These motors find a variety of applications in

various robots, field of application as per the design and consideration of the person who uses

them.


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In the model we have used the DC motors. The main components of the motor are the

rotors and the stators. Usually the rotors include the armature and the commutator assembly

and the stator includes the permanent magnet and the bushes assembly. The current is made

to flow through the windings of the armature; it sets up a magnetic field opposing the field set up

by the magnets. This produces a torque on the rotor. This causes the rotor to rotate. As the

rotor starts rotating the bushes and the commutator assemblies supply the current to the

armature so that the field remains opposed to the field set up by the magnets. In this way the

torque produced by the rotor is constant throughout the rotation.

D.C. motor principles:

1.

DC motors consist of rotor-mounted windings (armature) and stationary windings (field

poles). In all DC motors, current must be conducted to the armature windings by passing current

through carbon brushes that slide over a set of copper surfaces called a commutator, which is

mounted on the rotor. The commutator bars are soldered to armature coils. The

brush/commutator combination makes a sliding switch that energizes particular portions of the

armature, based on the position of the rotor. This process creates north and south magnetic

poles on the rotor that are attracted to or repelled by north and south poles on the stator, whichare formed by passing direct current through the field windings. It's this magnetic attraction and

repulsion that causes the rotor to rotate.

The advantages:-


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The greatest advantage of DC motors may be speed control. Since speed is directly proportional to

armature voltage and inversely proportional to the magnetic flux produced by the poles, adjusting the

armature voltage and/or the field current will change the rotor speed. Today, adjustable frequency

drives can provide precise speed control for AC motors, but they do so at the expense of power quality,

as the solid-state switching devices in the drives produce a rich harmonic spectrum. The DC motor has

no adverse effects on power quality.

The drawbacks:-

Power supply, initial cost, and maintenance requirements are the negatives associated with DC motors.

Rectification must be provided for any DC motors supplied from the grid. It can also cause

power quality problems.

The construction of a DC motor is considerably more complicated and expensive than that of an

AC motor, primarily due to the commutator, brushes, and armature windings. An induction

motor requires no commutator or brushes, and most use cast squirrel-cage rotor bars instead of

true windings-two huge simplifications. Maintenance of the brush/commutator assembly is significant compared to that of induction

motor designs.

In spite of the drawbacks, DC motors are in wide use, particularly in niche applications like cars and

small appliances.

SPECIFICATIONS:

RATINGS:

System voltage: 12 V

Operating temperature: 20C to +90C


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CHARECTERISTICS:

Typical light running current: 3.8 Amps

Rated torque at output gear: 18 to 25 Nm at 12V

Operating speed: 30 r.p.m

BATTERIES:

Voltage: 6 V

Current: 3.8 Amps

SENSORS IN automation or robots:

Sensors used as peripheral devices in robotics include both simple types such as limit

switches and sophisticated types such as machine vision. Of course, sensors are also used as

integral components of the robots position feedback control system. Their function as

peripheral devices in a robotic work cell is to permit the robots activities to be coordinated with

other activities in the cell. The sensors in robotics include the following general categories:

1. TACTILE SENSORS

These are the sensors, which respond to contact forces with another object. Someof these devices are capable of measuring the level of force involved.

2. PROXIMATE AND RANGE SENSORS

A proximity sensor is a device that indicates when an object but before contact has

been made when the distance between the objects can be sensed, the device is called range

sensor.

3. MISCELLANEOUS SENSOR

This includes the remaining kinds of sensors that are used in robotics. These include

sensors for temperature, pressure and other variables.

4. MACHINE VISION


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A machine vision is capable of viewing the workspace and interpreting what it sees.

These systems are used in robotics to perform inspection, part recognition and other similar

tasks.

Sensors are important components in work-cell control and in safety monitoring

systems.

MAGNETIC SENSOR-----

The reed switch is an electrical switch operated by an applied magnetic field. It was invented at Bell

telephone laboratories in 1936 by W.B.Elwood. It consists of a pair of contacts on ferrous metal reeds in

a hermetically sealed glass envelope. The contacts may be normally open, closing when a magnetic field

is present, or normally closed and opening when a magnetic field is applied. The reed relay is a type of

relay, in which a reed switch is mounted inside a coil.

The reed switch contains two magnetizable and electrically conductive metals reeds which have end

portions separated by a small gap when the switch is open. The reeds are hermetically sealed in

opposite ends of a tubular glass envelope.

A magnetic field from an electromagnet or a permanent magnet will cause the contacts to pull

together, thus completing an electrical circuit. The stiffness of the reeds cause them to separate, and

open the circuit, when the magnetic field ceases. A more complicated configuration contains a non-

ferrous normally closed contact is assured by plating a thin layer of precious metal over the flat

contact portions of the reeds. Since the contacts of the reed switch are sealed away from the

atmosphere, they are protected against atmospheric corrosion. The hermetic sealing of a reed switch

make them suitable for use in explosive atmospheres where tiny sparks from conventional switches

would constitute a hazard.

One important quality of the switch is its sensitivity, the amount of magnetic energy necessary toactuate it. Sensitivity is measured in units of Ampere-turns, corresponding to the current in a coil

multiplied by the number of turns. Typical pull-in sensitivities for commercial devices are in the10 to 60 AT range.


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Magnetic fields----------------Reed relays in general can be characterized as susceptible to the influence of

external magnetic fields. It is importance to keep the relays at a proper distance from each other

because of the possibility of magnetic interaction between them. Proper magnetic shielding must be

used to contain stray magnetic fields. When installing reed relays into equipment one should aware of

the devices within that equipment which can produce magnetic fields. The relays being installed into

that equipment should be positioned as far as away as possible from any stray magnetic fields and

should be shielded to prevent false operations.

Infrared sensor-----------

Passive infrared sensors (PIR sensors) are electronic devise which measure infrared light radiating from

objects in the field of view. PIRs are often used in the construction of PIR based motion detectors.

Apparent motion is detected when an infrared emitting source with one temperature, such as a human

body, passes in front of a source with another temperature, such as a wall.

All objects emit infrared radiation. This radiation is invisible to the human eye but can be detected by

electronic devices designed for such a purpose. The term passive in this instance means the PIR does not

emit any energy if any type but merely sits passive accepting infrared energy through the front of the

sensor, known as the sensor face. At the core of a PIR is a solid state sensor or set of sensors, with

approximately inch square area. The sensor areas are made from a pyroelectric material.

The actual sensor on the chip is made from natural or artificial pyroelectric materials, usually in the form

of a thin film, out of gallium nitride (GaN), caesium nitrate (CsNo3), polyvinyl fluorides, derivatives of

phenylpyrazine, and colbalt phthalocyanine, lithium tantalite (LiTaO3) is a crystal exhibiting both

piezoelectric and phyroelectric properties.

The sensor is often manufactured as part of an integrated circuit and may consist of one, two or four

pixels of equal areas of the pyroelectric material. Parts of the sensor pixels may be wired as opposite

inputs to the differential amplifier. In such a configuration, the PIR measurements cancel each other so


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that the average temperature of the field of view is removed from the electrical signal, an increase of IR

energy across the entire sensor is self-cancelling and will not trigger the device. This allows the device to

resist false indications of change in the event of being exposed to flashes of light or field-wide

illumination.

PIR-based motion detector----

In a PIR-based motion detector, the PIR sensor is typically mounted on aprinted circuit boardwhich also contains the necessary electronics required to interpret the signals from the chip. Thecomplete circuit is contained in a housing which is then mounted in a location where the sensor

can view the area to be monitored. Infrared energy is able to reach the sensor through the

window because the plastic used is transparent to infrared radiation (but onlytranslucentto

visible light). This plastic sheet prevents the introduction of dust and insects which could obscurethe sensor's field of view.

A few mechanisms have been used to focus the distant infrared energy onto the sensor surface.

The window may haveFresnel lensesmoulded into it. Aternatively, sometimes PIR sensors are

used with plastic segmentedparabolic mirrorsto focus the infrared energy; when mirrors areused, the plastic window cover has no Fresnel lenses molded into it. A filtering window (or lens)

may be used to limit the wavelengths to 8-14 micrometers which is most sensitive to human

infrared radiation (9.4 micrometers being the strongest).

The PIR device can be thought of as a kind of infrared 'camera' which remembers the amount of

infrared energy focused on its surface. Once power is applied to the PIR the electronics in thePIR shortly settle into a quiescent state and energize a smallrelay. This relay controls a set ofelectrical contactswhich are usually connected to the detection input of an alarm control panel. If

the amount of infrared energy focused on the sensor changes within a configured time period, the

device will switch the state of the alarm output relay. The alarm output relay is typically a"normally closed (NC)" relay, also know as a "Form B" relay.

A person entering the monitored area is detected when the infrared energy emitted from theintruder's body is focused by a Fresnel lens or a mirror segment and overlaps a section on the

chip which had previously been looking at some much cooler part of the protected area. That

portion of the chip is now much warmer than when the intruder wasn't there. As the intruder

moves, so does the hot spot on the surface of the chip. This moving hot spot causes theelectronics connected to the chip to de-energize the relay, operating its contacts, thereby

activating the detection input on the alarm control panel. Conversely, if an intruder were to try to

defeat a PIR perhaps by holding some sort of thermal shield between himself and the PIR, acorresponding 'cold' spot moving across the face of the chip will also cause the relay to de-

energizeunless the thermal shield has the same temperature as the objects behind it.
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Manufacturers recommend careful placement of their products to preventfalse alarms. They

suggest mounting the PIRs in such a way that the PIR cannot 'see' out of a window. Although the

wavelengthof infrared radiation to which the chips are sensitive does not penetrate glass verywell, a strong infrared source (a vehicle headlight, sunlight reflecting from a vehicle window)

can overload the chip with enough infrared energy to fool the electronics and cause a false (non-

intruder caused) alarm. A person moving on the other side of the glass however would not be'seen' by the PIR.

They also recommended that the PIR not be placed in such a position that anHVACvent wouldblow hot or cold air onto the surface of the plastic which covers the housing's window. Although

air has very lowemissivity(emits very small amounts of infrared energy), the air blowing on the

plastic window cover could change the plastic's temperature enough to, once again, fool the

electronics.

PIRs come in many configurations for a wide variety of applications. The most common used in

home security systemshas numerous Fresnel lenses or mirror segments and has an effective

range of about thirty feet. Some larger PIRs are made with single segment mirrors and can sensechanges in infrared energy over one hundred feet away from the PIR. There are also PIRs

designed with reversible orientation mirrors which allow either broad coverage (110 wide) orvery narrow 'curtain' coverage

Light dependant resistor--------

As the name suggests, a light dependant resistor is a component, whose

resistances changes when the amount of light falling on it (called the lightintensity) changes.

The resistance goes down as the amount of light goes up. Resistance decreases

as light intensity increases, light is low, dark is high (resistance).
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Photo Resistors (CDS), Light Dependent Resistor (LDR) - PGM Series

GENERAL RESISTORS INDEX

PGM Series - Light Dependent Resistor (LDR), Photo Resistors (CDS)

CR Series- Carbon Resistors

RCR Series- Anti-Surge Resistors

RSS, RSN Series- Metal Oxide Resistors

MF Series- Metal Film Precision Resistors

RDM Series- Carbon Film MELF Resistors

CCR Series- Carbon Composition Resistors

ZO, JW Series- Zero Ohm and Jumper Wire Resistors

KNP, KNPN Series- Wirewound Low-Inductance Resistors

KNP-VE Series- Vitreous Enamel Coated Wirewound ResistorsBWW Series- High Precision Wirewound Axial Moulded Resistors

FRN, FKN, FSQ Series- Metal Film, Wirewound, Cement Fusible Resistors

SQP, SQM, SQT, SQH, SQZ Series- Non-Corrosive Cement Resistors

RESISTORS - TECHNICAL STANDARDS AND USAGE METHODS

Resistor Precaution Usage

Resistor Forming and Dimensions

Glossary - Terminology of Resistors

Marking System - Resistor Color Code
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Terminology

Light Resistance: Measured at 10 lux with standard light A (2854K-color temperature) and 2hr.

preillumination at 400-600 lux prior testing.

Dark Resistance: Measured at 10th seconds after closing 10 lux.

Gamma characteristic:Under 10 lux and 100 lux and given by

= log(R10/R100) / log(100/10) = log(R10/R100)

R10, R100: resistance at 10 lux and 100 lux. The tolerance of is 0.1.

Pmax: Max. power dissipation at ambient temperature of 25C.At higher ambient temperature,the

maximum power permissible may be lowered.

Vmax: Max. voltage in darkness that may be applied to the device continuously.

Spectral peak: Spectral sensitivity of photoresistors depends on the wavelength of light they are

exposed to and in accordance with fig 2. The tolerance of spectral peak is 50nm.

Spectral Response

Physical and Environmental Characteristics

ITEM CONDITIONS PERFORMANCE

Solderability Put the terminals into welding tank at temp. 2305C

for 20.5s (terminal roots are 5mm away from the tin

surface).

wetting>95%

Temperature Changing Change of temperature in accordance with: TA: -40C

TB: +60C Number of cycles: 5 Exposure duration:

30min

Drift of R10 = 20%

No visible damage

Constant humidity and

heat

1. Put the device in test box at Temperature: 605C

Humidity: 90-95% Illumination: 0lux Duration: 100h

2. Take the device and measure after24h at normal

Drift of R10= 30%

No visible damage


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temperature and humidity.

Constant load

Temperature

At 255C

Illumination: 150lux at rated power

Duration: 600h

No visible damage

Wire Terminals Strength Bend the wire terminal at its root to 90 degree,and then

bend it to a opposite direction.

No visible damage

Vibration Frequency: 50Hz

Swing: 1.5mm with

Directions: parallel to ceramic substrate normal to

ceramic substrate. Duration:2h

A relay is a simple electromechanical switch made up of anelectromagnetand a set of contacts. Relays

are found hidden in all sorts of devices. In fact, some of the first computers ever built used relays to

implementBoolean gates.

Relay Construction

Relays are amazingly simple devices. There are four parts in every relay:

Electromagnet
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Armature that can be attracted by theelectromagnet

Spring

you can see that a relay consists of two separate and completely independent circuits. The first is at the

bottom and drives theelectromagnet. In this circuit, a switch is controlling power to the electromagnet.

When the switch is on, the electromagnet is on, and it attracts the armature (blue). The armature is

acting as a switch in the second circuit. When the electromagnet is energized, the armature completes

the second circuit and the light is on. When the electromagnet is not energized, the spring pulls the

armature away and the circuit is not complete. In that case, the light is dark.

When you purchase relays, you generally have control over several variables:

The voltage and current that is needed to activate the armature

The maximum voltage and current that can run through the armature and the armature contacts

The number of armatures (generally one or two)

The number of contacts for the armature (generally one or two -- the relay shown here has two, one of

which is unused)

Whether the contact (if only one contact is provided) is normally open (NO) or normally closed (NC)

Relay Applications

In general, the point of a relay is to use a small amount of power in theelectromagnet-- coming, say,

from a small dashboard switch or a low-power electronic circuit -- to move an armature that is able to

switch a much larger amount of power. For example, you might want the electromagnet to energize

using 5 volts and 50 milliamps (250 milliwatts), while the armature can support 120V AC at 2 amps (240

watts

Relays are quite common in home appliances where there is an electronic control turning on somethinglike amotoror alight. They are also common in cars, where the 12V supply voltage means that just

about everything needs a large amount of current. In later model cars, manufacturers have started

combining relay panels into the fuse box to make maintenance easier

An electromagnetic relay is a type of electrical switch controlled by anelectromagnet. Theelectromagnetic relay is used in a variety of applications, including alarms and sensors, signal

switching, and the detection and control of faults on electrical distribution lines. The

electromagnetic relay was invented in 1835, anditsstraightforward function has not changedmuch since. Consumers interact with the electromagnetic relay in a variety of forms daily, from

timed office lights to test buttons and otherquality controldevices.
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The core of the electromagnetic relay, naturally, is an electromagnet, formed by winding a coil

around an iron core. When the coil is energized by passing current through it, the core in turn

becomes magnetized, attracting a pivoting iron armature. As the armature pivots, it operates oneor more sets of contacts, thus affecting the circuit. When the magnetic charge is lost, the

armature and contacts are released. Demagnetization can cause a leap of voltage across the coil,

damaging other components of the device when turned off. Therefore, the electromagnetic relayusually makes use of a diode to restrict the flow of the charge, with the cathode connected at themost positive end of the coil.

Contacts on an electromagnetic relay can take three forms. Normally opened contacts connect

the circuit when the device is activated and disconnect it when the device is not active, like a

light switch. Normally closed contacts disconnect the circuit when the relay is magnetized, and a

change-over incorporates one of each type of contact. The configuration of the contacts isdependant upon the intended application of the device.

The electromagnetic relay is capable of controlling an output of higher power than the input, and

it is often used as a buffer to isolate circuits of varying energy potentials as a result. When a lowcurrent is applied to the electromagnet, throwing the switch, the device is capable of allowing a

higher current to flow through it. This is advantageous in some applications, such as trippingalarms and other safety devices, because a safer low current can be used to activate an

application requiring more energy.

mec human sensing and following trolley

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