Your Leading HK XRS Technology Ltd. Supplier
HK XRS TECHNOLOGY Ltd., established in HK,is one of Asia's leading distributors of semiconductors and electronic components. Our company has been committed to providing customers with high-quality electronic components products and services,including shortage and obsolete parts supply, PPV cost-saving solutions,non-core materials VMI solutions and extended inventory management with value-added service.Our company is able to to provide a wide range of products as well as supply chain solutions that can be customized to meet our customers' unique needs, maximize our efforts to achieve customers’ goals, and establish long-term friendly working relationships.
We have a professional and experienced team,from senior management to sales and purchasing. Our people are committed to providing our customers with unparalleled service. Our customer-care team works 24/7 to locate parts that fulfill the requirements of our customers. With years of industry expertise, our staff training professionals are dedicated to learning about our customers and encouraging an open dialogue to understand our customers' needs to provide better service.
On top of that,we have a highly-trained and professional logistics department that prides itself on getting your order to you safely and on time. You will be able to track your shipments online as soon as they are processed. We use all shipping companies, including FEDEX, UPS, DHL. and other freight forwarders to help you get your products from a preferred carrier at the lowest cost.
What Is Relays Electronics?
Relays are electric switches that use electromagnetism to convert small electrical stimuli into larger currents.
These conversions occur when electrical inputs activate electromagnets to either form or break existing circuits.
By leveraging weak inputs to power stronger currents, relays effectively act as either a switch or an amplifier for the electric circuit, depending on the desired application.
Benefits of Relays Electronics
The operation is simple
When learning how to operate a relay or putting it into action the method is really simple. The current that flows from the power source operates the coil of a relay which in turn creates a magnetic field that attracts an internal lever that changes the contacts over. Relays are generally controlled by using small currents and can control larger circuits when just using these low levels of current.
Isolation and separation of circuits
Relays ensure safe isolation between the control circuit and load circuits when used in certain applications. Relays are used to separate the control circuit from the circuit that has a load on it. They are not just a device used for control, they can also be used for safety applications.
Small in size
Relays are generally small components that can be integrated into most panels and control circuits. Instead of using a range of contacts and coils relays compact this all into one unit that consists of a base and a relay. Sometimes these relays are interchangeable as they can be plugged into a base.
Easy to troubleshoot
Relays are extremely easy to test and perform fault-finding activities on. The wiring diagram of a relay can either be found printed on the side of the relay or in the operation/installation manual. As relays are also low-cost components they can be cheaply replaced to rule them out as a problem. A button can also be located on the top of a relay which can manually operate the contacts of a relay.
Control of more than one component
Relays can be used in a system to control up to 4 different switching applications. They can be used to switch more than one contact over at a time. This again saves space and gives much more options when designing a circuit. The output contacts of a relay can be used to switch different load circuits or components that may have different voltage or current levels.
Low-cost components
Relays are relatively cheap electrical components. Due to their low price and ease of use relays are found across a wide range of electrical circuits and systems.
Ease of installation
Relays are extremely easy electrical components to install. Most relays or relay bases can be mounted onto din rail. Some types of relays are interchangeable, this means if the contacts or coil fail the relay can be replaced without disconnecting any wires.
Ease of cable termination
Relays generally have a range of different cable termination methods. The options generally include screw, fork, and spring-style termination methods. The termination method on a relay is generally secure and protects against cables coming out when located in environments that have vibrations. Relays that are designed to be used on PCBs have pins that can be soldered to the board.
Can be used to switch ac or dc
Relays can be used to switch AC or DC loads depending on the spec and type of the relay.
Relays Have Long Lifespans
Relays tend to have long lifespans and do not need changing on a regular basis. If your relay requires changing on a frequent basis it could show a problem with the circuit or it could be the wrong relay for the job. A typical lifespan of a relay is around 1 – 1.5 million cycles.
Can offer multi-voltage inputs
Relays can offer multi-voltage inputs, this means that a range of inputs can be used on the same relay. This can reduce levels of stock and also confusion for anyone when replacing faulty components. A range of different voltage input levels are available for relays.
Voltage amplification
Relays can be operated with very small levels of voltage and used to control circuits with much higher levels of voltage. An example of this is a 24 V DC relay could be used to control a circuit with a 230 V AC load in it.
Contact operation is visible
Some relays have LEDs located on them which show if the contacts have been switched or not. You can also see this by just looking at the relay but the use of LED modules makes this task much easier. A test button is also sometimes located on the top of a relay which can operate the contacts when pressed.
Maintenance Free
Relays are electrical components that require no maintenance. When they have been fitted to a system or circuit they can just sit there and do their job time after time.
Types of Relays Electronics
Electromagnetic relay
An electromagnetic relay is a switch that uses an electromagnet to control the on and off of the operating circuit. It uses low voltage and weak current to control high voltage and high current circuits, and can also end remote operation and production automation. It plays an increasingly important effect in modern days.
Thermal relay
Thermal relays are generally composed of heating elements, control contacts, and action systems, reset mechanisms, current setting devices and temperature compensation elements. It generates heat from the current flowing into the thermal element, which causes the bimetallic strips with different expansion coefficients to deform. When the deformation reaches a certain point, it pushes the connecting rod to disconnect the control circuit, so that the contactor loses power and the main circuit disconnects, in order to protect the motor from overloading.
Photoelectric relay
A relay that uses the photoelectric effect to operate. It is composed of light-emitting elements (such as small incandescent lamps, gallium phosphide diodes, etc.) and photosensitive devices. When the signal added to the light-emitting element reaches a certain value, the effect of light causes the resistance of the photosensitive device to change sharply, thereby closing or breaking the circuit.
Polarized relay
A polarized relay refers to a relay that is actuated by the combined action of the polarized magnetic field and the magnetic field generated by the control current through the control coil. The polarized magnetic field is generally generated by magnetic steel or a polarized coil with a direct current; the suction direction of the relay armature depends on the direction of the current flowing in the control winding. It can be used as components of pulse generation, DC and AC conversion, summation, differentiation, and signal amplification in automatic devices, remote control, and telemetry devices, and communication equipment. It has the outstanding advantages of high sensitivity and fast action.
Current Relay
The coil of the current relay is connected in series in the circuit and acts according to the magnitude of the coil current. The coil wire of this kind of relay has few thick turns and low coil impedance.
The function of the current relay: It works according to the current signal, and also determines the contact action according to the current of the coil. The coil needs to be connected in series with the load circuit when installing. According to the coil current, it can be divided into AC and DC. According to the action current, it can be divided into overcurrent and undercurrent.
Voltage relay
The voltage relay has many coils turns and thin wires. It is connected in parallel in the loop when working, and the circuit is turned on or off according to the voltage across the coil.
The function of the voltage relay: It works according to the voltage signal, and determines the action of the contact according to the magnitude of the coil voltage. The coil needs to be connected in parallel with the load during installation. The voltage relay can be divided into AC and DC according to the coil voltage and can be divided into overvoltage and undervoltage according to the operating voltage.
Auxiliary relay
The power supply used for the electromagnetic coil of the intermediate relay is DC and AC. Commonly used intermediate relays have two series, JZ7 and JZ8.
The role of the intermediate relay: play a role in converting and transmitting control signals. Its input signal is the power-on and power-off signal of the coil, while the output signal is the contact action of the intermediate relay. In essence, it is a kind of voltage relay, which has the characteristics of a large number of contacts.
Time relay
When the input signal is added or removed, the output part needs a delay or time limit to close or disconnect the relay of the controlled circuit until a specified time.
Speed relay
The speed relay is a relay that acts when the speed reaches a specified value. The speed relay is usually connected with the shaft of the motor when in use. The function of the speed relay is to coordinate the signal with the contactor depending on the speed to realize the reverse braking of the motor. Therefore, the speed relay is also called the reverse brake relay.
Classified by relay contact load
Micro-power relay
When the contact open circuit voltage is DC 27V, the contact rated load current (resistive) is 0.1A, 0.2A.
Weak power relay
When the contact open circuit voltage is DC 27V, the contact rated load current (resistive) is 0.5 ampere, 1 ampere relay.
Medium power relay
When the contact open circuit voltage is 27 volts DC, the contact rated load current (resistive) is 2 amperes and 5 amperes.
High-power relay
When the contact open circuit voltage is 27 volts DC, the contact rated load current (resistive) is 10 amperes, 15 amperes, 20 amperes, 25 amperes, 40 amperes.
Classified by the dimensions of the relay
Miniature relays
Relays with the longest side dimension not greater than 10 mm.
Subminiature relays
Relays whose longest side dimension is greater than 10 mm but not greater than 25 mm.
Small relays
Relays whose longest side dimension is greater than 25 mm but not greater than 50 mm.
Classified by the protection characteristics of the relay
Hermetically sealed relays
Use welding or other methods to seal the contacts and coils in the 2. enclosure, isolate them from the surrounding medium, and have a low leakage rate.
Enclosed relay
A relay in which the contacts and coils are enclosed (unsealed) and protected in a casing.
Open type relay
A relay that does not require a protective cover to protect the contacts and coils, etc.
Applications of Relay
The applications of the relay are limitless, its main function is to control the high voltage circuit (230V circuit AC) with the low voltage power supply (a DC voltage).
Relays are not only used in the large electrical circuits but also used in computer circuits in order to perform the arithmetic and mathematical operations in it.
Used to control the electric motor switches. To turn ON an electric motor we need 230V AC supply but in few cases/applications, there may be a situation to switch ON the motor with a DC supply voltage. In those cases, a relay can be used.
Automatic stabilizers are one of its applications where a relay is used. When the supply voltage is other than the rated voltage, set of relays sense the voltage variations and controls the load circuit with the help of circuit breakers.
Used for the circuit selection if there exists more than one circuit in a system.
Used in Televisions. An old picture tube television’s internal circuitry works with the DC voltage but the picture tube needs a very high AC voltage, in order to turn on the picture tube with a DC supply we can use a relay.
Used in the traffic signal controllers, temperature controllers.
Components of Relay
The relay operates both electrically and mechanically. It consists electromagnetic and sets of contacts which perform the operation of the switching. The construction of relay is mainly classified into four groups. They are the contacts, bearings, electromechanical design, terminations and housing.
Contacts
The contacts are the most important part of the relay that affects the reliability. The good contact gives limited contact resistance and reduced contact wear. The selection of the contact material depends upon the several factors like nature of the current to be interrupted, the magnitude of the current to be interrupted, frequency and voltage of operation.
01
Bearing
The bearing may be a single ball, multi-ball, pivot-ball and jewel bearing. The single ball bearing is used for high sensitivity and low friction. The multi-ball bearing provides low friction and greater resistance to shock.
02
Electromechanical design
The electromechanical design includes the design of the magnetic circuit and the mechanical attachment of core, yoke and armature. The reluctance of the magnetic path is kept minimum for making the circuit more efficient. The electromagnet is made up of soft iron, and the coil current is usually restricted to 5A and the coil voltage to 220V.
03
Terminations and Housing
The assembly of an armature with the magnet and the base is made with the help of spring. The spring is insulated from the armature by moulded blocks which provide dimensional stability. The fixed contacts are usually spot welded on the terminal link.
04
Relay Selection Considerations
The following factors must be considered while selecting a relay for any application.
Nominal voltage
The voltage at which the coil is designed to operate.
Rated power
The power consumed by the coil at normal room temperature.
Contact rating
The current carrying capacity and voltage rating of their contacts.
Contact mechanism
The number of contacts required and the contact configuration (NO/NC/changeover).
Environmental protection
The degree of sealing required, meaning, whether the external casing of relay is necessary or not?
Insulation resistance
Insulation resistance between any two sets of contacts and that between the contacts and the coil.
How Relays Work
A control coil surrounds the iron core. The electromagnet starts energizing when the current flows through the control coil then intensifies the magnetic field. The electromagnet becomes connected to the power source through the contacts to the load and a control switch. The upper contact arm becomes attracted to the lower fixed arm and then closes the contacts that result in a short circuit. The contact then moves in the opposite direction and creates an open circuit once the relay has been de-energized.
The movable armature will return to its initial position when the coil current is off. The force that causes its movement will be almost the same as the half strength of the magnetic force. Spring and gravity provide this force.
Relays can operate in two ways. The first is in low voltage application, and the other is in high voltage application. It is used to reduce the noise of the whole circuit in low voltage applications. On the other hand, relays reduce arcing in high voltage applications.
Our Partners
We work closely with top electronic component manufacturers such as Intel, Texas Instruments, ADI, Microchip, STMicroelectronics, NXP, and others to offer diverse options. From chips to sensors and specialized equipment, we ensure your project gets high-quality components from leading global brands.
FAQ
Q: What is the function of the relay?
Q: What is a relay system used for?
Q: What are relays usually used for?
Q: What is the difference between a switch and a relay?
Q: What are the three basic functions of a relay?
Q: What are the 3 main parts of a relay?
Q: What is relay in simple words?
Q: Can you bypass relay?
Q: Why are relays important in electronics?
Q: Is relay a circuit breaker?
Q: How do you connect a relay to a circuit?
Q: Does a relay increase voltage?
Q: How does a relay work simple?
Q: What are the two most common faults in a relay?
Q: Are relays input or output?
Q: Which two main principles do most relays work?
Q: What is the difference between a contactor and a relay?
Q: What can I use instead of a relay?
Q: How many circuits are in a relay?
Q: Will a relay work if wired backwards?
We're professional relays electronics suppliers and distributors in China, specialized in providing high quality electronic components & supplies. We warmly welcome you to wholesale relays electronics in stock here from our factory. Contact us for quotation.
nail, window hardware, lock