Solid State Relays

A solid-state relay (SSR) is an electronic switching device that switches on or off when a small external voltage is applied across its control terminals.

SSRs consist of a sensor which responds to an appropriate input (control signal), a solid-state electronic switching device which switches power to the load circuitry, and a coupling mechanism to enable the control signal to activate this switch without mechanical parts.

These relays may be designed to switch either AC or DC to the load. It serves the same function as an electromechanical relay, but has no moving parts.


Solid-state relays are composed of semiconductor materials, including thyristors and transistors, and have current ratings that extend from a few microamps for low-power packages up to around a hundred amps for high-power packages.

They have extremely fast switching speeds usually ranging between 1 to 100 nanoseconds and are not easily affected by contact wear.

Solid State Relay

 

Solid State Relay

Applications

Heater Control: These Relays enable high-precision, high-frequency temperature control for reflow ovens, molding machines, and sintering ovens. Models are available with fault detection and cyclic control.

Three Phase Motors: Solid-state Contactors provide smooth starting and stopping functions to suppress sudden motor operation and thus reduce mechanical stress. They are ideal for conveyor belts and other applications requiring smooth movement.

Socket/Plugin Type: Also  suitable for high-frequency switching, signal exchange with controllers, and other I/O applications.


Shortcomings


Solid-state relays have several shortcomings: a high susceptibility to damage (a relatively high vulnerability to overloads in comparison to electromechanical relays); limited switching arrangements (SPST switching); a need for finer tuning due to high "on" resistances.

Switched-mode power supply

A switched-mode power supply (switching-mode power supply, SMPS, or switcher) is an electronic power supply that incorporates a switching regulator to convert electrical power efficiently. Like other power supplies, an SMPS transfers power from a source, like mains power, to a load, such as a personal computer, while converting voltage and current characteristics.

 

 

SMPS

 

 

The electric energy is not normally used in the form in which it was produced or distributed. Practically all electronic systems require some form of energy conversion. A device that transfers electric energy from a given source to a given load using electronic circuits is referred to as power supply. Of course, it does not really supply power, it just converts it, so "converter" is a more accurate term for such a device.

 

 

Flow chart

 

Switching regulators are used as replacements for linear regulators when higher efficiency, smaller size or lighter weight are required. They are, however, more complicated; their switching currents can cause electrical noise problems if not carefully suppressed, and simple designs may have a poor power factor.

Miniature circuit breaker(MCB)

Miniature circuit breaker(MCB) can be defined as a automatically operated electrical switch designed for the purpose of protection of any electrical circuit from damage that can occur by overload or short circuit. Basic function of MCB is to detect a fault condition and to stop flow of electrical current. Contrary to a fuse, which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation.

Types of MCB

Depending upon our requirement and phase of current to be used we use various MCBs like 1 Pole,2 Pole, 3 Pole, 4 Pole

1 Pole MCB

 

2 Pole MCB

 

3 Pole MCB

 

4 Pole MCB



MCB (Miniature Circuit Breaker)—rated current not more than 100 A. Trip characteristics normally not adjustable. Thermal or thermal-magnetic operation. Breakers illustrated above are in this category.

There are three main types of MCBs:

1. Type B - trips between 3 and 5 times full load current

2. Type C - trips between 5 and 10 times full load current

3. Type D - trips between 10 and 20 times full load current


The miniature circuit breaker (MCB) plays an important role in providing overcurrent protection and a disconnect means in electrical networks.


The Magnetic trip unit protects against a short circuit. The magnetic trip unit is comprised of an electromagnet and an armature.






 

 
 


 


 

Push Button

What is Push-button?

Push button is a component which connects two points in a circuit when we press it. In industry it can be used to provide input to circuit.

Push Buttons

Circuit Diagram

In the daigram shown below point A & B are connected when switch is pressed.

Application

The "push-button" has been utilized in calculators, push-button telephones, kitchen appliances, and various other mechanical and electronic devices, home and commercial.

In industrial and commercial applications, push buttons can be connected together by a mechanical linkage so that the act of pushing one button causes the other button to be released. In this way, a stop button can "force" a start button to be released. This method of linkage is used in simple manual operations in which the machine or process have no electrical circuits for control.

Photoelectric Sensor

1. Photoelectric sensor, or photo eye, is a device used to detect the distance, absence, or presence of an object by using a light transmitter, often infrared, and a photoelectric receiver. They are used extensively in industrial manufacturing. There are three different functional types: opposed (through beam), retro-reflective, and proximity-sensing (diffused).
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3. 

   Photo electric sensor

   Application
4. Photoelectric sensors use a beam of light to detect the presence or absence of an object. This technology is an ideal alternative to inductive proximity sensors when you require long sensing distances or when the item you want to sense is non-metal. Our photoelectric sensors satisfy applications found in many industries, such as material handling, packaging, food processing, and transportation. For your specialized applications that require a non-standard connector or cable, we can customize the sensor connections.
5. Modes
6. In (through beam) arrangement consists of a receiver located within the line-of-sight of the transmitter. In this mode, an object is detected when the light beam is blocked from getting to the receiver from the transmitter.
7. A retro-reflective arrangement places the transmitter and receiver at the same location and uses a reflector to bounce the light beam back from the transmitter to the receiver. An object is sensed when the beam is interrupted and fails to reach the receiver.
8. A proximity-sensing (diffused) arrangement is one in which the transmitted radiation must reflect off the object in order to reach the receiver. In this mode, an object is detected when the receiver sees the transmitted source rather than when it fails to see it.

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   Modes of Photoelectric sensors

   Photoelectric sensors offer many advantages as compared to other technologies such as inductive,capacitive,magnetic & ultrasonic.They are price competitive as well when compared to other technologies.
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Solenoid Valve

A solenoid valve is an electromagnetically operated valve.It is controlled by an electric current through a solenoid: in the case of a two-port valve the flow is switched on or off; in the case of a three-port valve, the outflow is switched between the two outlet ports. Multiple solenoid valves can be placed together on a manifold.

Solenoid valves are the most frequently used control elements in fluidics. Their tasks are to shut off, release, dose, distribute or mix fluids. They are found in many application areas. Solenoids offer fast and safe switching, high reliability, long service life, good medium compatibility of the materials used, low control power and compact design.

Solenoid Valve

Operation

There are many valve design variations. Ordinary valves can have many ports and fluid paths. A 2-way valve, for example, has 2 ports; if the valve is open, then the two ports are connected and fluid may flow between the ports; if the valve is closed, then ports are isolated. If the valve is open when the solenoid is not energized, then the valve is termed as normally open (N.O.). Similarly, if the valve is closed when the solenoid is not energized, then the valve is termed normally closed.

Operation of Valve

Common uses

Solenoid valves are used in fluid power pneumatic and hydraulic systems, to control cylinders, fluid power motors or larger industrial valves. Automatic irrigation sprinkler systems also use solenoid valves with an automatic controller. Domestic washing machines and dishwashers use solenoid valves to control water entry into the machine. Solenoid valves are used in dentist chairs to control air and water flow. In the paintball industry, solenoid valves are usually referred to simply as "solenoids." They are commonly used to control a larger valve used to control the propellant (usually compressed air or CO₂). In addition to this, these valves are now being used in household water purifiers (RO systems).

Besides controlling the flow of air and fluids, solenoids are used in pharmacology experiments, especially for patch-clamp, which can control the application of agonist or antagonist.

Rotary Encoder

What is Rotary Encoder

It is an electro-mechanical device that coverts the angular motion/position of the shaft to analog or digital code.It is also known as shaft encoder.

Application

Rotary encoders can be used in all applications that require monitoring rotation rate, speed, acceleration and direction. These sensors can be utilized in many applications found in mechanical engineering, the conveyor industry, material handling and the packaging industry. You are certain to find a suitable rotary encoder for your application from our broad product offering.

In automation, rotary encoders are used as sensors for angle, position, speed and acceleration. Linear motion can also be measured through the use of spindles, gear racks, measuring wheels or cable pulls.

Rotary encoders convert a mechanical input into electrical signals, which can be processed by counters, tachometers, programmable logic controllers and industrial PCs.

Rotary encoders in many application which require precise shaft unlimited rotation specialy in robotics,industrial control,special purpose photographic lense,computer input devices(mouse & trackballs)

Absolute rotary encoder ROQ 425

There are two types of rotary encoder :

• Absolute
• Incremental(Relative)

A Gray code absolute rotary encoder with 13 tracks. At the top the housing, interrupter disk, and light source can be seen; at the bottom the sensing element and support components.

                                                               

Absolute Encoder

Output of absolute encoder indicates current position of the shaft.It maintains position information when power is removed from the system and when power is again to the system the position is retrieved.

Incremental Encoder

Output of incremental encoder supplies information regarding motion of the shaft in terms of speed,distance,position.It doesn't power up with fixed relation between encoder state and position.

Use in industry

Encoders used on servomotors

Rotary encoders are often used to track the position of the motor shaft on permanent magnet brushless motors, which are commonly used on CNC machines, robots, and other industrial equipment. Incremental (Quadrature) encoders are used on Induction Motor type servomotors, but absolute encoders are used in Permanent Magnet Brushless Motors, where applicable. In these applications, the feedback device (encoder) plays a vital role in ensuring that the equipment operates properly. The encoder synchronizes the relative rotor magnet and stator winding positions to the current provided by the drive. Maximum torque results if the current is applied to the windings when the rotor magnets are in a particular position range relative to the stator windings. The motor will perform poorly or not at all if this timing is not adjusted correctly. Improper encoder alignment on the motor can actually cause it to run backwards sometimes resulting in a hazardous run away condition. Correct alignment is essential to proper operation of these motors.