An LCD controller or LCD Display driver or an LCD Driver is an integrated circuit that offers an interface between the LCDs and the Microcontroller (MCU) or Microprocessor (MPU) system. Generally, a standard parallel or serial electronic interface is used for connection with MCU or MPU. LCD Drivers can be discrete chips executed in standard semiconductor chip bundles, with enormous I/O interconnects to a different LCD glass through gadgets like bonded flexible looms or elastomeric connectors. To beat the extremely high I/O interconnection necessities of the controller to the glass, the controller chip can be bonded straightforwardly to the glass, with the serial interface and power supply being the main I/O associations.

                                                        The above figure is that of an LCD circuit.

Display drives drive a matrix of liquid crystal segments or dots. The enormous number of spots broadens the achievable number of ports that can be associated with the chip. To beat this exceptional technique for driving, a dot matrix grid is implemented. This is accomplished by implementing the LCD as a cluster, or network of lines and sections, and driving the lines and segments by exceptional waveform shapes. The signal pattern on the LCD Controller ports is defined already to empower driving without contention and work in order to not harm the LCD.

LCD Drivers / Controller also consists of characters stored in a different language to enable driving the display efficient. They also come with programmable shape memory such that they can offer user-defined characters. The manufacturer of the driver/controller will generally offer a generic software driver to provide interfacing with the device. They usually provide regulation of voltage for changing the port waveform amplitude, managing the contrast and adapt to several ambient temperatures. They also come with the inbuilt functionality to manage backlighting.

Though a short one but this was all we have regarding LCD drivers. Hope you liked going through it. Brands that manufacture them are Texas Instruments, NXP and Maxim. Make sure to follow them using the links as provided.

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Motor drives refer to those circuits that help in running a motor. It can be said in other words that they help in motor interfacing. The motor can be easily interfaced with the drives. Their selection totally depends upon the kind of motor being utilized as well as their ratings (like the voltage, current, etc.). 

Let’s take a reference of a DC motor and understand its major components.

The major components of motor drive present in DC motors are a Motor Driver IC, a controller, Power Supply Unit, DC motor and required connections to the motor.

• Controller – The controller can be a microcontroller or a microprocessor.
• Motor Driver IC – Motor Driver IC (or Motor Driver Circuits) are current amplifiers which convert low current signal taking from the controller to high current signals.
• Motor – Motor is referred to as a mechanic or electric device that can cause motion. Some motors like a stepper motor, brushless DC motor, and normal DC motor might need a driver circuit or a driver IC while interfacing with the controller. DC motor is referred to as that kind of motor that helps in converting DC into Mechanical power. The brushless DC motor consists of an inverter that produces an AC signal to drive the motor and a DC power source. Stepper motor is referred to as a brushless DC electric motor that helps in converting electrical pulses into discrete mechanical motions.
• Power Supply Unit – Offers the needed power to the motor drive.

DC Motor Driver Circuits

Motor Driver circuits are basically current amplifiers. These motor drivers behave like a bridge between the motor and the controller. Motor drivers are produced using discrete parts which are coordinated inside an IC. The motor driver circuit or a motor driver IC takes in a low current signal as an input. The main functionality of the IC is to convert this Low Current signal to a High Current signal which is then provided to the motor. The motor can be a brushed DC motor, brushless DC motor, stepper motor or other DC motors, etc.

Characteristics:

• Better performance
• Supports with the high current drive
• Gives a high level of functionality
• Offers High voltage
• It comes with an assurance scheme to avert the disappointment of motors because of any issues.

What is the need for Motor Driver Circuits (ICs)

While interfacing the motor with the controller, one of the basic needs for the controller's operation is a small amount of current with a low voltage. But the motor needs a high current and voltage for its own operation. Thus we can say that the output generated from the processor or controller is not much to drive a motor. In this case, direct interfacing of controllers to the motor is beyond the realm of imagination and we use a Motor Driver IC.

This was all we have regarding Motor Drives. Hope you liked it. Brands that manufacture them are Schneider, Omron, and Applied Motion. Make sure to follow them using the links as provided.

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The act of sensing the absence or the presence of a substance (object) with a non-contact or contact sensing device is known as presence sensing. The sensors generate an output signal (electrical) that can be utilized to control processes or equipment.

Limit switches are a category of sensing device that helps in detecting the presence and absence of objects. Mechanical limit switches refer to those switches that can be activated mechanically i.e. they consist of some kind of lever, arm, plunger, knob, etc. which is mechanically or physically activated. Other kinds of switches/sensors include light sensors, proximity sensors, etc.

As said earlier, these limit switches help in the sensing of objects in industrial applications. The device is named as limit switch due to the operation it performs. As the target (object) comes in close contact with the switch’s operator, it moves the actuator to the limit where the electrical contacts change state. Because of this mechanical activity, the electrical contacts are either closed (in an open circuit) or opened (in a closed circuit). Capacitive proximity, photoelectric sensors, and inductive proximity carry out this same procedure through non-contact detection.

Let's have a look at some of the basic functions linked with limit switches.

• Counting
• Detecting Speed
• Detecting Absence or Presence
• Detecting Travel limit and Positioning
• Detecting Range of Movement
• When an unsafe condition forms up it breaks the live circuit.

Limit switches have found its use in many commercial and industrial applications which requires safety. Let’s check out some of its strengths as well as its weaknesses.

Strengths

• Limit switches can withstand several environments.
• It provides high accuracy, repeatability, and precision.
• It’s quite a good economic sensing solution.
• It’s not a big deal to switch high currents (approx. 10A).

Weaknesses

• The mechanical component used in it may wear out.
• It needs to make physical contact with an object to actuate.

Advantages of using Limit Switches

• It can operate multiple loads.
• It consumes less electrical energy.
• It can be utilized in nearly any industrial habitat.
• Loads can be switched with high inductance.
• It’s very much specific regarding repeatability and accuracy.

Disadvantages of Limit Switches

• These switches are by and large confined to hardware working at moderately low speeds.

Basic Limit Switch Design and Terminology

• Pretravel – It is the angle or the distance that the actuator must go through to trip the contacts.
• Operating Point – It is the position of the actuator where the contact break to the position of operation.
• Release point – It is the position of the actuator at which the contacts come back to their initial state.
• Differential – It is the length between contacts reset and contacts trip.
• Overtravel – It is the movement of the actuator past the contacts trip point.
• Initial Position – It is the position of the actuator when no external force is applied to it.
• Operating Force (Torque) – It is the amount of force needed to move the actuating element.

This was all we have regarding limit switches. Brands that manufacture them are Omron, Honeywell, and QUADRANT. Make sure to follow them using the links as provided.

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An SSR or a Solid State Relay is a piece of electronic switching equipment which when applied by a small external voltage across its control terminal switches ON and OFF. SSRs have a sensor in them that reacts to a proper control signal (input), a piece of switching equipment that changes power to the load circuit, and a coupling process to empower the control signal to initiate this switch without the help of any mechanical parts. The relay might be made to switch either DC or AC to the load. It offers the same functionality as that of an electromechanical relay but comes with no moving parts.

Packaged Solid State Relay utilizes power semiconductors like transistors and thyristors to change the electrical current approximately to hundred Amperes. The switching speed of solid-state relays is comparatively faster than that of the electromechanical relays. In addition to that, it has no physical contacts to wear out. The devices using the Solid State Relays must take into consideration their higher value of “ON” state resistance as well as their lower capacity to hold out against momentary overload. In contrast to an electrochemical relay, the SSR offers only a limited amount of switching arrangement.

Operation

A Solid State Relay that works based on a particular MOSFET (or multiple ones in a parallel array) works well with DC loads. This MOSFET comes with a substrate diode which helps in the conduction of electricity in the reverse direction. Thus it is not possible for a particular MOSFET to stop the current in both directions. To carry out an AC operation, 2 MOSFET are positioned one after the other with their source pins integrated. The output side is connected with their drain pins. The substrate diodes are reverse biased alternately such that the current can be blocked whenever the relay is OFF. Whenever the relay is ON both the gates are positively biased comparative with the source by the photograph diode.

Parameters

Solid State Relay is governed by several parameters. They are:

• Required activating output current and voltage
• Required activating input current and voltage
• AC or DC
• Resistance or potential drop affecting the output current and thermal resistance.
• SSRs are much less sensitive to operating environment and storage factors like humidity, mechanical shock, external magnetic fields, and vibration.

Advantages of SSR over Mechanical Relays:

• Slimmer and smaller than a mechanical relay.
• It carries out a totally silent operation.
• The switching speed of SSRs is much faster than that of electromechanical relays.
• The output resistance does not vary regardless of the amount it is utilized.
• The operation is bounceless and clean.

Disadvantages:

• For the gate charged circuit an isolated bias supply is needed.
• There is a chance of false switching because of the voltage’s momentary variations.

Hope you liked going through the article on Solid State Relay. Brands that make SSRs are Crydom, Omron and Phoenix Contact. Make sure to follow them using the links as provided here. Thank you for reading.

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A switch that can be operated electrically is known as a relay. It consists of several operating contact terminals as well as a group of input terminals for multiple or single control signals. The switch might come with a different number of contacts in several contact forms, like break contacts, make contacts, etc.

Relays have found its uses at places where several circuits need to be controlled by a particular signal or where it is important to control the circuit by a low power signal which is independent. Firstly relays were utilized as signal repeaters in long-distance telegraph circuits. Here they used to revive the signal rolling in from one circuit by broadcasting it on another circuit. Relays were utilized excessively in early computers as well as telephone exchanges to carry out logical operations.

The basic version of relays takes the help of an electromagnet to open or close the contacts, however, other working standards have been concocted like the solid-state relays which utilize the semiconductor properties for controlling. Relays that comes with multiple operating coils and adjusted working attributes are utilized in protecting electrical circuits from faults and overload. In current electric power frameworks, these capabilities are taken care of by digital instruments known as protective relays.

Types of Industrial Relay

• Coaxial Relay – Whenever a single antenna is shared between a radio receiver and a transmitter, coaxial relays are used. It helps in switching the antenna from the receiver to the transmitter. Thus the receiver is defended from transmitter's high power.

• Contactor – A heavy-duty relay that comes with a high current rating which is utilized for switching lighting loads and electric motors is known as a contactor.

• Force-guided contacts relay - These types of relay come with contacts that are linked together mechanically such that whenever the relay coil gets energized or de-energized, all of them moves together.

• Latching Relay – A latching relay is basically an electromechanical switch that helps in controlling small flow of electrical current with a larger flow of current.

• Machine tool relay - A machine tool relay is a relay that is used mainly for industrial control of transfer machines, machine tools, etc.

• Mercury Relay – The relay that takes the help of mercury as a switching element is known as mercury relay.

• Multi-Voltage relay – These relays are made in such a manner that they can withstand a wide range of frequency (0 to 300 Hz) as well as a wide range of voltage (24 to 240 VAC).

• Polarized relay – This relay positions the armature in between the poles of a permanent magnet only with a motive to increase sensitivity.

• Static Relay – This kind of relay comes with electronic circuitry to imitate each one of those attributes which are accomplished by moving parts in an electromagnetic relay.

This was all we have regarding Industrial Relays. Hope you enjoyed going through it. Brands that manufacture them are Phoenix Contact, TE Connectivity, and Omron. Make sure to visit them from the links as provided.

Light curtains come under optoelectronic devices that are utilized to defend personnel in the proximity of moving machinery that can cause harm like winders, palletizers, and winders. Light curtains can be utilized as an alternative to traditional machine guarding and other mechanical barriers. By decreasing the requirement for physical barriers and guards, these safety light curtains can uplift the practicality of the hardware they are guarding. It should also be noted that by the use of light curtains the efficiency and the operability of the machinery can be improved. 

Description

Light curtains can be categorized under those gadgets that are known as Presence Detection devices. Other popular Presence Detection devices include laser scanners and pressure-sensitive safety mats. Most significant uses of safety relays are in industries that work upon robotic cell setup.

Light curtains come with a transmitter and a receiver. The transmitter makes a projection of several parallel light beams in an array to the receiver. The receiver contains photoelectric cells that can easily absorb these array of light beams. Whenever an object is seen breaking one or more beams, the guarded equipment is notified with a signal to stop.

The beam of light produced from the transmitter is sequenced, in a steady progression, and is pulsed at a particular recurrence. The receiver is optimized to accept only a specific frequency and pulse from its respective transmitter. This helps in rejecting infrared light that is spurious and in this way improves their reasonableness as segments inside a security framework.

Generally, it is seen that a safety relay is connected with these light curtains that help in nullifying motive power from the hazard. Safety relays can be given muting usefulness which empowers the brief disabling of the security capacity to enable articles to go through the light curtains without stumbling the safety relay. This is especially valuable for hardware which has a few Semi-Automatic processes.

Applications of Safety Light Curtains: Point of Operation Vs Perimeter

Industrial facilities and manufacturers utilize light curtains for safety in 2 general situations i.e. Point of Operation & Perimeter. Let's discuss them in brief.

• Point of Operation

In this case, the individual positions the light curtains at the point of material handling, let's say under a hydraulic press. It is done with an only intention to make sure that nobody enters the danger area while the machine is being operated.

• Perimeter

Conversely, perimeter guards allude to depicting an entire working space or room, let's say for robotic arms. It makes sure that no object or person comes in the boundary of the movement of the machine.

Advantages of Safety Light Curtain

Light curtains provide several advantages over physical barriers, such as.

1. It's quite easy to access machine guarded by safety light curtain rather by a physical barrier.
2. To perform semi-automatic processes and routine maintenance can be done efficiently.

Hope you liked the above article on safety light curtains. Brands that manufacture them are Panasonic, Omron, and Honeywell. Make sure to follow them using the links as provided.

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A photo eye or a photoelectric sensor is a gadget that helps in discovering the present and absence of the object as well as its distance by utilizing a light transmitter, generally infrared, with a photoelectric receiver. They are most commonly used in manufacturing in the industry.

Types

There are 3 types of Photoelectric Sensors. Let’s have a look at them.

A photoelectric sensor that is self-contained comes with the optics in addition to the electronics. It needs only a source of energy. The sensor does its own output switching, amplification, modulation, and demodulation. Some sensors that are self-contained also supports an option for counters or built-in control timers. Because of the advancement in the tech world, today, self-contained photoelectric sensors are reduced in sizes.

Remote photoelectric sensors that are utilized in remote sensing comes with only the optical part. The hardware for amplification, output switching and power input are situated elsewhere, generally in a control panel. Thus allowing the sensor to get very small. In addition to that, the controls of the sensor are increasingly available, since they might be greater.

When space is one of the constraints or the environment is excessively hostile for using remote sensors, we take fiber optics into consideration. Fiber optics are latent mechanical detecting segments. They can be utilized either with self-contained sensors or with remote ones. They have neither any moving part nor comes with any electrical circuitry. It can pipe light safely into and out of any hostile environment.

Modes

There are 3 different modes of photoelectric sensors. They are as follows:

• Opposed (through-beam)

Pros:

1. The sensing range is the longest.
2. It is mostly accurate.
3. It is very much reliable

Cons:

1. It is important that it should get installed at 2 points in the system i.e. receiver as well as an emitter.
2. It is a bit costly as it required a separate receiver and emitter.

• Retro-Reflective

Pros:

1. Its sensing range is much better than that of diffuse.
2. It is slightly less accurate than through beam.
3. It is very much reliable.

Cons:

1. Its sensing range is lesser than through beam.
2. It is a bit more costly than diffuse
3. It is important that it should get installed at 2 points in the system i.e. reflector as well as the sensor.

• Diffuse (Proximity Sensing)

Pros:

1. It needs to be installed only at one point.
2. It is much cheaper than reflective as well as through-beam.

Cons:

1. It requires more setup time.
2. Accuracy level is lesser than retro-reflective or through-beam.

This was all we have regarding photoelectric sensors. Hope that you enjoyed reading through the article. Brands that manufacture photoelectric sensors are Omron, Panasonic, and Sick. Make sure to follow them using the links as provided.

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A counter or a tachometer is an instrument that helps in measuring the speed of rotation of a disk or shaft, like that present in a motor. This device generally shows the RPM (Revolution Per Minute) on a calibrated analogue dial. The digital displays are getting much popular these days.

The word speedometer as well as tachometer have the same meaning i.e. a device used in measuring the speed. But by convention in the world of automobiles, one is used for representing the speed of the vehicle and the other one represents that of the engine.

The 1^st made tachometer depended on estimating the Centrifugal force. Its operation was similar to the Centrifugal governor. The person who invented this device was Dietrich Uhlhorn, a German Engineer, in 1817. From 1840, this device is utilized to calculate the engine’s speed.

Revolution counters or tachometers present in aircraft, cars and other automobiles show the rotation rate of the crankshaft of an engine. It has also got a marking that points to the range that is safe for the rotation speed. This helps the driver in choosing the right gear and throttle setting. Overheating and inadequate lubrication is the major consequence of their prolonged use at high speed.

In analogue tachometers, if the speed rises more than the safe operating speed then it is displayed by a zone of the gauge with a red mark. Thus, offering to ascend to the declaration of “redlining” an engine - firing it up to the most extreme safe point of confinement. The modern cars used these days also come with this red mark in their tachometer. However, they are of no use as their engines come with a limiter which automatically limits its speed to prevent the car from any damage. Diesel engines with conventional mechanical injector frameworks come with an integral speed limiter which stops the engine to speed up. Thus the tachometer used in them lacks redline.

The trucks and tractors come with a tachometer that has a green arc in them. This green arc lets the driver know the speed at which the engine is producing the maximum torque. Some tractors also come with a PTO (Power Take-Off). The tachometers in them help in letting the driver accustomed to the speed of the engine needed to rotate the PTO at the standardized rate. Tractors having more than one ‘road gear’ often have tachometers with multiple speed scale. The green arc is said above is also present in the tachometer of an aircraft to show the cruising speed range of their engine.

Traffic Engineering

From the above discussion, it is clear that tachometers help in estimating the volume (flow) and speed of the engine. A vehicle is fitted with a sensor and conducts "tact runs" that keep a record of the traffic information. The information gathered here is a complement to loop detector data. To get measurably huge outcomes needs a large number of runs. Nonetheless, due to the cost and spacing tach runs is a popular practice.

This was all we had about counters and tachometers. Brands that manufacture them are Panasonic, Omron, and Crouzet. Make sure to check them out through the links as provided.

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A varistor is an electrical device having an electrical resistance that differs with the potential applied to it. A varistor is popularly known as Voltage Dependent Resistor (VDR). It possesses a non-ohmic and non-linear Current-Voltage characteristic which is equivalent to a diode. Unlike the diode, it has a similar characteristic for the flow of both directions of current. Customarily, varistors were made by joining 2 rectifiers i.e. either the germanium-oxide or the copper-oxide rectifier in a configuration that is anti-parallel. The electrical resistance of the varistor is high at low voltage but as the voltage increases the resistance decreases. The varistors that are used presently are fundamentally dependent on sintered ceramic metal-oxide materials. On a microscopic scale, it shows directional behavior. This category is popularly known as MOV or Metal Oxide Varistor.

Varistor serves as a compensation and a control element in the electrical circuit either to defend against excess voltage or to offer optimal operating conditions. When utilized as defending devices, they shunt the current established by the exorbitant voltage away from touchy segments when activated.

Composition

As said earlier, the newest form of varistor that is used is the Metal Oxide Varistor. This kind of varistor is constituted by a ceramic mass of zinc oxide grains with metal oxides (like a small quantity of cobalt, bismuth, manganese oxides) placed in the middle of 2 metal plates, which comprise the device’s electrodes. A diode junction is formed between each grain and its neighbor.

When the electrodes are given a small potential difference then only a small amount of current flows through the diode junction which is a result of reverse leakage. On the other hand when a large voltage is applied on the electrodes a large amount of current flows, as the diode junction separates itself because of the combination of electron tunneling and thermionic emission. The consequence of the above-said behavior is a non-linear Current-Voltage characteristic where the MOV possesses a low resistance at high voltage and high resistance at low voltage.

Voltage Rating

MOVs are categorized by the range of voltage that they can endure without damage. The other parameter is the varistor’s breakdown voltage, maximum current, energy rating in joules, response time and operating voltage.

The rating of energy is regularly characterized utilizing institutionalized transients like 10/1000 microseconds or 8/20 microseconds. Here 10 microseconds are the front time of the transient and 1000 microseconds is the time of half value.

Capacitance

The range of capacitance for varistors which are consumer-sized i.e. 7 to 20mm in diameter is from 100pF to 2,500pF. Varistors that are used in micro electric protection have low capacitance like around 1pF. You can get this kind in cellular phone. These varistors having low capacitance cannot withstand the flow of a large amount of current as the PCB mount size is compact.

Response time

The response time of the MOV isn't institutionalized.

Hope you liked the article on Varistors. Brands that make them are Littelfuse, EPCOS, Panasonic. You can refer to them using the links as provided. Thank you for reading.

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