Solid State Relay

Your Professional Solid State Relay Supplier

Zhejiang Qianji Relay Co., Ltd was established in 2000 and has more than 23 years experience of relay industry. The company is a modern and professional enterprise researching, developing, producing, and selling relays.

Why Choose Us

01/

Wide Product Range
The company specializes in the production of more than 100 series and 2,000 specifications of various small relays, high-power relays, imported relays, automotive relays, time relays, magnetic latching relays, solid-state relays, counters, temperature controllers, relay sockets, switches, etc.

02/

Wide Range of Applications
Our relay products are mainly used in power systems, industrial automation, transportation, medical equipment, household appliances, and other fields.

03/

Quality Assurance
We have passed ISO9001 international quality system certification, and our products have passed non-toxic and environmentally friendly tests; some products have obtained American UL, German TUV certification, CE certification, and CQC certification.

04/

Broad Market
There are dealers all over the country and our products are exported to the Middle East, South America, Southeast Asia, Taiwan, South Korea, Australia, Europe, the United States, and other countries and regions.

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Definition of Solid State Relay

A solid state relay (SSR) is an electronic switching device that switches on or off when an external voltage (AC or DC) is applied across its control terminals. They serve the same function as an electromechanical relay, but solid-state electronics contain no moving parts and have a longer operational lifetime. SSRs consist of a sensor which responds to an appropriate input (control signal), an 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. They may be designed to switch either AC or DC loads. Packaged SSRs use power semiconductor devices such as thyristors and transistors, to switch currents up to around a hundred amperes. SSRs have fast switching speeds compared with electromechanical relays, and have no physical contacts to wear out. SSRs are unable to withstand a large momentary overload the way an electromechanical relay can, and have a higher "on" resistance.

How Do Solid State Relays Work

The key characteristic of a solid state relay is that it requires no moving parts to perform the task of opening or closing contacts on a circuit. Unlike a mechanical relay, there's no positional change of any component within the solid state relay when it switches between on/off, open/closed states. Instead, a solid state relay works by converting the incoming electrical control signal to an optical one, often output via an infrared LED or similar (note, however, that the term 'solid state relay' is a generic one, and covers a variety of configurations).
This optical signal is then fired across a small gap of (permanently) open space within the module - known as an opto-isolator - to where it's received by a photosensitive transistor, which in turn converts and sends on the signal to further electrical components. This completes the circuit and ultimately triggers the desired action, all without any contacts in the solid state relay ever coming into direct physical contact with one another.

Features of Solid State Relay

Faster Switching

SSRs can turn on and off much faster than electromechanical relays, typically in the microsecond range, allowing them to respond to rapid changes in input signals.

No Mechanical Parts

SSRs do not have any mechanical parts that can wear out or fail over time, making them more reliable and durable than electromechanical relays.

Less Noise

Compared to electromechanical relays, SSRs produce less electrical noise, which can reduce interference with other sensitive electronic equipment.

No Contact Bounce

SSRs have no contact bounce, which can cause parasitic signals and delayed response times in electromechanical relays.

No Magnetic Interference

SSRs do not have electromagnetic coils, which means they do not generate any magnetic interference.

No Arcing

SSRs have no contacts that can arc, which can damage the contacts and surrounding components.

Advantages of Solid State Relay

Design Simplicity
The circuit board footprint and total volume of solid state relays are much smaller than EMRs of similar specifications. SSRs can also be lighter than EMRs by up to 70 percent, depending on the power. The size and weight advantages make SSRs highly desirable for embedded systems in order to save valuable installation space. SSR operation is also position insensitive, so they are suitable for mounting in either a vertical or horizontal position. Some SSRs have housing with anti-rotation barriers. Although they are smaller in size, SSRs are not less powerful than EMRs. Optical coupling completely isolates the circuits of the relay, eliminating the failure caused by high voltage.

Long Life
Since solid state relays do not include any moving parts and contacts, there are no issues of arcing or mechanical wear. Consequently, the expected lifetime of SSRs is 50 times longer than EMRs, making them an ideal solution for applications that require frequent operation.

Low Power Consumption
Solid state relays do not need to energize a bulky coil and open and close contacts like EMRs do. This means that SSRs use significantly less power to operate than EMRs. The input power of SSRs must only be enough to drive an optical coupler LED, which is very low energy consumer. EMRs require input power in the range of hundreds of milliwatts to a few watts, while SSRs need an input power of microwatts to a few milliwatts.

Fast Switching
SSRs provide much faster switching when compared to EMRs. SSRs switch on/off faster because there are no physical parts to move. The switching time depends on LED switching on/off time which responds to a control signal almost instantaneously (less than 100 µs). The average switching time of EMRs is from 5 to 15 ms.

Quiet Operation
SSRs use electronic circuits to provide switching. Since they do not have moving parts, they have completely silent switching operation. This is a highly desirable feature in various commercial and medical applications.

Minimum EMI Noise
Low noise SSRs provide both zero-voltage switching on and zero-current switching off, reducing the electromagnetic interference (EMI) noise to a negligible amount. The zero-crossover switching feature is one of the most important advantages of SSRs. This feature enables switching off the AC loads when the sine load current is zero, eliminating issues such as the arcing and electrical noise. Even when the input control signal is removed, the switching devices continue conducting until the current drops below its threshold value. This is why SSRs will never switch off the load in the middle of a sine wave peak, which is especially important in the case of inductive loads—otherwise large voltage spikes can appear. The zero voltage turn-on and zero current turn-off feature provides the minimum electrical disturbances generated by SSRs. These zero-switching relays are the most widely used relay type.

Ideal for Harsh Environments
In industry, harsh environments are characterized by the following factors: temperature, dust, humidity, vibration and mechanical stress. Since solid state relays have no moving parts and are entirely enclosed in housing, they are well-suited for harsh environment applications. In addition, SSR operation does not cause sparking, making SSRs suitable for combustible environments. External magnetic fields have negligible effects on SSRs as well.

Types of Solid State Relay

Instant ON SSRs

The instant ON SSR instantly switches on the load circuit when a sufficient input voltage is applied. It turns off when the input voltage is removed and the load current crosses the next zero. The instant ON SSRs are designed to control the inductive loads. The practical applications are in switching of contactors, magnetic valves, starters, etc.

Zero Switching SSRs

A zero switching SSR switches on when an input voltage is applied and the load ac voltage crosses the next zero voltage. It switches off when the input voltage is removed and the load ac voltage reaches zero volts. A zero crossing circuit is used to achieve the operation of zero switching relay. The zero crossing circuit detects the zero cross of voltage and activates the TRIAC. The zero switching relays are mainly designed for controlling of resistive loads. Some applications are temperature control of heating elements, soldering irons, ovens, etc.

Peak Switching SSRs

The peak switching SSR switches on when the output ac voltage reaches its next peak after applying the required control input voltage. It turns off after the removal of the input control voltage and the output ac current crosses its zero. A peak control circuit is used to detect the peak of output ac voltage and fires the TRIAC when the output ac voltage hits its peak. These are used in control of switching of transformers, large motors and high inductive loads etc.

Analog Switching SSRs

The switching of analog switching SSRs depend on the amplitude of input voltage. The starting output voltage of analog switching SSRs being proportional to the input control voltage. It switches off when the control input voltage is removed and the output ac current crosses its zero. The analog switching SSRs are equipped with a synchronizing circuit that controls the amount of output voltage as a function of the control input voltage. The analog switching SSRs are mainly designed for closed loop applications like temperature control.

Solid State Relay Mount Types

Solid State Relay PCB Mounts
PCB-mount solid state relays are, as their name suggests, intended to be mounted directly to a printed circuit board. This makes for quick and straightforward installation on motherboards and other types of PCB, either via push-in pin fittings or with a requirement for soldering directly to the PCB surface.

Solid State Relay DIN Rail Mounts
DIN-mount solid state relays are designed to be fitted to a range of standard DIN rail setups, for easy installation and access alongside other industrial control equipment housed in a variety of PCL racks and enclosures.

Solid State Relay Panel and Chassis Mounts
Panel-mount solid state relays are among the most widely available and flexible switch types and are manufactured to be attached flush with various sorts of industrial and equipment panels, hatches or heatsinks. Chassis-mount versions offer similar functionality and convenience. Both types are typically attached via screw-fitting solid state relay mounts that allow for direct fixing through the SSR base, body, or via purpose-designed eyelets (also known as through-hole mounts).

Solid State Relay Heatsink Mounts
Heatsink mounts for solid state relays allow for the easy attachment of a heatsink cooling solution (usually passive, but active cooling options can also be used in more extreme environments) for the switch.

Solid State Relay Plug-In Mounts
Various sorts of plug-in solid state relay switches are also designed around quick and convenient plug-and-play functionality - the exact type of plug attachment featured will depend on what the SSR is intended to be inserted into and where, but they're typically intended for direct PCB insertion.

Applications of Solid-State Relay

Solid-state relays are used in a variety of applications from home automation to industrial motor control. But it is especially well-suited for process applications where a PLC or other microcontroller-based circuit controls a machine tool. Below are some of the most common applications.

Motor Control
One of the most common applications for solid-state relays is motor control. You can use SSRs to control AC and DC motors, from small motors in home appliances to large industrial motors.

Lighting Control
Solid-state relay applications also include switching loads such as light bulbs and LED arrays. In these applications, these relays have the advantage of fast switching speeds, which is important for certain lighting effects.

Heater Control
Solid-state relays are widely used in heating (and cooling) systems for air conditioners, electric ovens, and industrial heaters or furnaces. Other devices can also be used. However, SSRs have the advantage of being able to handle fairly high voltages while still being compact in size.

Medical Equipment
Due to their critical nature, medical equipment requires specialized control systems to turn the power on and off. Controllers with solid-state relay switches are perfect for this requirement and are very reliable and use very low input signals.

Automotive Solid State Relays
In the automotive field, SSR relays are important switching devices. They are rapidly replacing older mechanical relays in engine management systems, headlamp dimming circuits, and fog lamp control applications.

Water Pumps
Water pumps contain electric motors and other systems that need to be turned on and off as needed. You can do this with an AC solid-state relay.

CNC
CNC stands for Computer Numerical Control and refers to the process by which computers are used to automate machine tools. This technology is used in various industries such as woodworking, metalworking, and plastics processing.

Communication
Communication systems need to switch high currents and voltages quickly and reliably. This is why solid-state relays are often used in these applications due to their better features and functionality.

Components of an Solid State Relay

Solid state relays use a different kind of semiconductor material instead of mechanical contacts to switch electrical signals. The main components of the SSR include:
Control Circuit: This circuit includes input signal conditioning for conditioning the input signal to the output drive circuit. The input signal can be AC or DC, depending on the type of SSR.
Output Drive Circuit: This circuit consists of output drive transistors or thyristors, which are used to switch the load. Output driver circuits are usually designed to handle load current and voltage.
Isolation Circuit: The isolation circuit is used to isolate the control circuit and the output drive circuit. This is necessary to prevent any interference between the control and output circuits.
Heat Sink: Since the SSR generates heat during operation, a heat sink is required to dissipate this heat. Heat sinks are usually made of aluminum or copper and are designed to provide effective cooling to the SSR.
Overvoltage Protection Circuit: This circuit is used to protect the SSR from high voltage spikes that could damage the output drive circuit.
Status Indicators: Typically contain LEDs or other status indicators to provide a visual indication of SSR operation.

The Difference Between Solid State Relay and Mechanical Relay

Relays are electrical switches used to control the flow of electrical current. Mechanical relays use mechanical contacts and electromagnets to switch currents, while solid-state relays (SSRs) use semiconductor devices to switch currents. Solid-state relays are more reliable and last longer than mechanical relays. They are also more resistant to vibration and shock, making them ideal for industrial applications. However, solid-state relays are more expensive and require more power to operate than mechanical relays.

What is a Solid-State Relay?
Solid state relays (SSRs) use semiconductor switches such as thyristors, triacs, or MOSFETs to control current flow without any mechanical contact. The input signal to the SSR is usually a low-voltage DC signal, which triggers the semiconductor switch and allows current to flow through the SSR. The output voltage of an SSR is usually in the form of an AC or DC power source, which is turned on or off depending on the input signal.

What is Mechanical Really?
The input signal to a mechanical relay is usually a low-voltage DC signal that energizes the electromagnet and closes the mechanical contacts, allowing current to flow through the relay. The output voltage of a mechanical relay is usually AC or DC, which is switched on or off through mechanical contacts.

Solid State Relay Vs Mechanical Relay
Unlike mechanical relays, solid-state relays do not change the position of any components when switching between on/off and on/off states. Instead, solid-state relays work by converting incoming electrical control signals into light signals, usually output through infrared LEDs or similar devices. The choice between solid state and mechanical relays will depend on the specific requirements of the application. Solid-state relays are typically used in applications requiring fast switching times, high reliability, and low noise, while mechanical relays are typically used in applications requiring low cost and high current capacity.

Factors to Consider When Selecting a Solid State Relay

Determine Your Load Voltage and Current
You will need to determine the maximum AC or DC voltage and current for your load in order to choose the proper solid state relay.

Determine the Required Control Voltage or Input Signal to Turn on the Solid State Relay
Unlike EMRs (Electromechanical Relays) which are typically controlled by a fixed voltage, Solid State Relays have a wide range of input control signals, either Vdc, Vac, or dual Vac/Vdc. If you wish to proportionally control your load, you'll need some additional specs to choose the proper SSR.

Define How Many Poles You Wish to Switch
When you select a solid state relay you need to know how many poles are to be sw itched to the load. We offer single-phase, two-phase and three-phase solid state relays. For a single-phase AC load, you'll need a one-pole AC SSR (single phase). For three-phase AC loads, you'll need to decide if you want to switch all three phases to the load, or if you want to switch two of the three-phases, the third is then directly connected.

Take into Consideration What Type of Load You Have
Each load type (resistive, inductive, or capacitive) will function better with certain types of SSRs.
Examples : Resistive Loads is best controlled with zero-cross Solid State Relays ; Random Solid State Relays are ideal for Inductive Loads ; for DC Loads, DC Solid State Relays will be required.
Furthermore, for some abnormal loads, specific instructions must be followed to prevent excessive current and overvoltage from damaging the device.
When in use, the switching current flowing through the SSR output should not exceed the rated output current under the relevant temperature, as stipulated in the product data sheet.

Determine Your Mounting Style : Panel or Din-Rail Mount
You need to choose which SSR will fit your application in terms of housing, connection type, etc. Our offers are available in different mounting configurations with various wiring options: PCB or DIN rail mounted, with screw connections or removable spring terminals, etc.

Measure the Ambient Temperature
The maximum SSR current rating depends on the ambient temperature where it will be installed (High temperatures can reduce the SSR's current rating). We recommend to mount the SSR on a heatsink to optimize its performance and to reach nominal performance. It is essential to know the operating ambient temperature as this will determine which heatsink to choose.

Our Factory

The new factory covers an area of more than 8,000 square meters and a construction area of more than 15,000 square meters. With its absolute advantages in product quality and performance, the company has become a leader in the relay industry.

Common Problems of Solid State Relay

Q: What is a solid-state relay?

A: A solid-state relay is an electronic switching device that controls the flow of electrical power between two terminals without the use of any mechanical components. It acts as an alternative to electromechanical relays (EMRs) and uses semiconductors to perform the switching function. SSRs have become increasingly popular due to their durability, reliability, and fast switching capabilities.

Q: What is the working principle of a solid-state relay?

A: The basic working principle of an SSR involves the use of an input control signal to trigger an output load. When a small control voltage is applied to the input side of the SSR, it activates an optocoupler or an opto-isolator. The optocoupler consists of a light-emitting diode (LED) and a photosensitive semiconductor, which are electrically isolated from each other.
Upon receiving the input control signal, the LED emits light, which falls on the photosensitive semiconductor. This causes the semiconductor to conduct, effectively closing the circuit between the load and the power source. When the control signal is removed, the LED stops emitting light, and the semiconductor returns to its non-conductive state, opening the circuit and disconnecting the load from the power source.

Q: What are the types of solid-state relays?

A: There are various types of solid-state relays available in the market, based on their input control signals and output load capabilities. Some of the most common types of SSRs include:
AC Output SSR: These SSRs are designed to control alternating current (AC) loads. They typically use a triac or a thyristor as the output switching device.
DC Output SSR: These SSRs are used for controlling direct current (DC) loads. They generally use a transistor, such as a MOSFET, as the output switching device.
AC/DC Output SSR: These SSRs can control both AC and DC loads, making them suitable for a wide range of applications.
Input/Output SSR: These SSRs have both input and output stages within the same device, enabling them to accept a wide range of input control signals and drive various types of loads.

Q: What are the advantages of solid-state relays?

A: Solid-state relays offer numerous benefits over their electromechanical counterparts, including:
Longer lifespan: SSRs have no moving parts, which eliminates mechanical wear and tear, leading to a longer service life.
Fast switching: SSRs can switch on and off in microseconds, enabling rapid and precise control of electrical loads.
Low noise: The absence of mechanical contacts means that SSRs generate minimal audible noise during operation.
Shock and vibration resistance: Due to their solid-state construction, SSRs are more resistant to mechanical shocks and vibrations than electromechanical relays.
Optical isolation: The use of optocouplers in SSRs provides electrical isolation between input and output circuits, reducing the risk of electrical interference and damage to sensitive components.

Q: Are there any limitations to solid-state relays?

A: Despite their numerous advantages, solid-state relays also have some limitations:
Heat generation: SSRs generate heat during operation, which can affect their performance and reliability if not properly managed with adequate heat sinks or cooling systems.
Higher cost: SSRs are generally more expensive than electromechanical relays, especially for high-power applications.
Leakage current: Unlike electromechanical relays, SSRs may have a small amount of leakage current even when they are in the off state, which can be problematic in some applications.
Lower maximum current rating: SSRs often have lower maximum current ratings compared to electromechanical relays, which can limit their suitability for high-current applications.

Q: What are the applications of solid-state relays?

A: Solid-state relays are used in a wide range of applications, including:
Industrial automation: SSRs are used in process control systems, programmable logic controllers (PLCs), and other automation equipment for precise control of motors, pumps, valves, and other electrical loads.
Lighting control: SSRs are used in lighting systems to control the intensity and duration of illumination, as well as for dimming and color-changing applications.
Home appliances: SSRs are found in devices such as washing machines, air conditioners, and microwave ovens for accurate control of heating elements, motors, and other electrical components.
Renewable energy systems: SSRs are used in solar and wind power systems to manage the flow of electrical energy between storage batteries, inverters, and the grid.

Q: Why use solid-state relays instead of magnetic electromechanical relays?

A: SSR technology continues to displace EMRs in many general-purpose applications. The main difference between SSRs and EMRs is that SSRs provide completely electronic switching and do not contain any moving contacts. Electronic devices such as silicon-controlled rectifiers enable this electronic current switching. SSRs can be fabricated with SCRs (silicon-controlled rectifiers), TRIACs (triodes for alternating current) or switching transistors, but MOS transistors are commonly used as the switching element.SSRs are designed to ensure complete electrical isolation between input and output. When SSRs are switched off they have a very high resistance, and when they are conducting they have a very low resistance. SSRs can switch both AC and DC currents. SSRs can provide a wide range of current depending on the application, rating from microamps to hundreds of amps. SSRs provide a voltage range of 3 VDC to 32 VDC, making them useful for most electronic circuits. The SSR control signal input circuit consumes less power than EMRs. Additionally, the switching time of SSRs is much shorter compared to EMRs.

Q: How to select a solid state relay based on load types?

A: There is no problem for SSR to switch on/off the normal loads, but some special load conditions should also be considered so as to avoid the unnecessary damages to the device caused by excessive impact current and overvoltage. In the use, the steady-state current flowing through SSR output should not exceed the rated output current under relevant temperature as stipulated in the product specifications. The possible inrush current cannot exceed the overload capacity of the relay. Generally, there should be some margin.
The rated current of SSR is selected according to different load types.The instantaneous current of resistive load, inductive load and capacitive load is large when starting. Even for the load with pure resistance, the resistance value is small in cold state because of the positive temperature coefficient, so it has a large starting current. For example, the starting current of asynchronous motor is 5 to 7 times as large as rated value, and the starting current of DC motor is larger. Moreover, the inductive load has higher back EMF. This is an indeterminate value, varying with L and DI/DT, usually 1 to 2 times higher than the power supply voltage, which is superimposed with the power supply voltage. Thus there exists a voltage 3 times higher than the power supply voltage. Capacitive load has potential risk. When starting, the capacitor (load) is equivalent to a short circuit because the voltage at both ends of the capacitor cannot be mutated.
Therefore, when selecting solid state relays, users should carefully know about the surge characteristic of load, and then make a decision. SSR can bear the surge current in the case of ensuring its stable working. Generally, the ordinary SSRs can be selected based on the 2/3 of its rated current value. The enhanced SSRs may be selected according to the parameters provided by the manufacturer. In the harsh conditions such as industrial control sites, it is recommended to leave enough voltage and current margin.

Q: How to select a right SSR according to the circuit's power voltage, transient voltage and dv/dt?

A: DC solid state relay is only suitable for controlling DC power and load, AC solid state relay is only for controlling AC power and load, and AC/DC universal(bidirectional)solid state relay is applied to AC, DC and bidirectional square wave control.
The voltage of load power supply can't exceed rated output voltage of solid state relay, and can't be lower than stipulated minimum output voltage. The maximum value of voltage peak which is possibly added to solid state relay should be lower than the value of its transient voltage. When switching the AC inductive load, single-phase and 3-phase motors, or energizing these loads, the output side of SSR may appear twice the voltage peak of the power supply.
For inductive and capacitive loads, when AC solid state relay turns off at the zero current, the power voltage is not zero, and adds to solid state relay output end with a large dv/dt value. Therefore, high dv/dt solid state relay should be selected.

Q: What are the requirements for the input ends of solid state relay?

A: ATO provides two types of solid state relays, DC and AC input control. DC control input all use constant current source circuit, with input voltage range of 3-32V DC, convenient to connect with TTL circuit and microcomputer interface. The positive and negative polarity of control terminals should be paid attention to under installation. AC control input of solid state relay is also available with control voltage ranging from 70 to 280V AC.

Q: How to protect the overcurrent, overvoltage, overheating of solid state relay?

A: Over current and short circuit may cause permanent damage to the internal SCR of solid state relay in the use. In this case, installing fast fuse and air switch in the control loop can be taken into account for the protection. So, solid state relays should be selected with output protection, built-in RC snubber circuits and MOV, which can absorb surge voltage and improve dv/dt tolerance. It is also feasible to connect RC snubber circuits and MOV in parallel at relay output end to achieve output protection.
The load capacity of solid state relays is greatly affected by the ambient temperature and its own temperature rise. In the installation and usage, good heat emission conditions should be guaranteed. In general, for the SSR with rated operating current more than 10A, radiators should be equipped with. For more than 100A, a radiator and a fan should be equipped with for forced cooling. In the installation, it should pay attention to good contact between the bottom of the relay and the radiator, and consider the amount of thermal grease coated appropriate to achieve the best cooling effect.

Q: Can solid state relays be used in parallel for higher current applications?

A: Yes, some SSRs are designed to be used in parallel to achieve higher current-carrying capacity. Solid state relay (SSR) outputs can be wired in parallel enabling the user to benefit from lower on-resistance and higher load currents for AC/DC switching applications.

Q: Do solid state relays have a minimum load requirement?

A: Solid State Relays Require a Minimum Load, and will NOT function correctly unless minimum load requirements are met. External snubber circuitry may be required for certain applications. If a device turns on, but does not turn off, this usually indicates a need for a external snubber circuit.

Q: Are there any restrictions on mounting orientation for solid state relays?

A: Orientation restrictions may vary, so it's crucial to follow the manufacturer's guidelines for proper mounting to ensure optimal performance and heat dissipation.

Q: Are solid state relays polarity sensitive?

A: You can solid state relays designed to operate off both DC and AC. If your relay is designed for AC, it will be OK if you apply DC of any polarity provided it is within the volatge ratings. If it is a DC relay it is going to depend on whether it has been designed to to be reverse polarity protected.

Q: Are heat sinks necessary for solid state relays?

A: Solid State Relays controlling loads rated at more than 5 amps require a heat sink for reliable operation. The size and thermal rating of the heat sink increases as the load current carried by the SSR increases, or as the operational ambient temperature increases.

Q: Do solid state relays require an external power source?

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

Q: How are solid state relays protected against overcurrent and overvoltage?

A: Since their inception, solid state relays (SSRs) have relied on overvoltage suppression devices such as metal oxide varistors (MOVs) to protect their outputs from voltage extremes such as overvoltage transients.

Q: Can solid state relays be dimmed for lighting control?

A: Some AC solid-state relays can be used for dimming, and others cannot because they switch on at the zero-crossing point to prevent noise on the AC line.

Q: What is the typical lifespan of a solid state relay?

A: An EMR has an average lifespan of one million cycles, whereas an SSR has a lifespan of roughly 100 times that. Now in order to benefit from a solid state relay's practically infinite lifespan, the SSR Relay needs to be maintained and used properly.

As one of the leading solid state relay manufacturers and suppliers in China, we warmly welcome you to buy high-grade solid state relay in stock here from our factory. All our products are with high quality and low price.

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