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.

View all the Motor Drives

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.

View all the Limit Switches

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.

View all the Solid State Relay – Industrial Mount

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.

View all the Safety Light Curtains