11 best solid state relays
Solid state relays (SSRs) are electronic switching devices used in various industrial and electrical applications to control the flow of electrical current without the use of moving parts, such as those found in traditional electromagnetic relays. SSRs offer several advantages over traditional relays, including faster switching times, longer lifespans, and reduced noise.
Here are some key characteristics and features of solid state relays:
Operation: SSRs work on the principle of using semiconductors (usually a combination of thyristors and triacs) to switch the load on or off. They do not have any mechanical contacts like traditional relays.
Isolation: SSRs provide electrical isolation between the control input and the load output.This isolation helps protect sensitive control circuits from voltage spikes and noise on the load side.
Switching Speed: Solid state relays can switch much faster than electromechanical relays, typically in microseconds. This makes them suitable for applications that require high-speed switching.
Longevity: SSRs have a longer operational life compared to traditional relays because they lack moving parts that can wear out over time.
Noiseless Operation: Since SSRs don't have mechanical contacts, they operate silently without generating audible clicks or vibrations.
Efficiency: SSRs are more energy-efficient because they have lower power consumption and generate less heat when compared to traditional relays.
Sensitivity: SSRs are highly sensitive to their input signals, which means they can be triggered by low-level control signals, making them suitable for microcontroller and digital logic-based control systems.
Applications: Solid state relays find applications in a wide range of industries, including industrial automation, HVAC (Heating, Ventilation, and Air Conditioning), medical equipment, automotive, and more. They are used to control heaters, motors, lights, and other electrical loads.
Protection Features: Some SSRs come with built-in protection features such as overcurrent protection, overvoltage protection, and thermal shutdown to ensure safe operation.
Heat Dissipation: SSRs can generate heat during operation, especially when switching high currents. Adequate heat sinking and cooling measures may be required to prevent overheating.
Zero-Crossing: Many SSRs are designed to switch on and off at the zero-crossing point of the AC waveform to minimize voltage spikes and reduce electromagnetic interference (EMI).
In summary, solid state relays are electronic switching devices that offer advantages in terms of speed, reliability, and noiselessness compared to traditional electromagnetic relays. They are widely used in various industrial and electrical applications where precise and efficient control of electrical loads is required.
Below you can find our editor's choice of the best solid state relays on the market
MYSWEETY 3PCS SSR-40DA Solid State Relay Single Phase Semi-Conductor Relay Input 3-32V DC Output 24-380V AC
MYSWEETY
Product description
Features:
Model number: SSR-40DA
Theory: Solid State Relay
Input: 3-32 V DC
Output: 24-380 V AC
Rated operating frequency: 50 / 60Hz
1. Triac output, zero voltage open, zero off
2. Optical isolation between input circuit and output circuit
3. Inputs-between the output isolation voltage 2500 V
Application:
SSR series solid state relay with flame-retardant plastic housing, epoxy casting compound, wiring screw terminals with high structural strength, impact strength, vibration resistance, the input drive current small can be convenient and computer terminals and a variety of digital programmable circuit interface, widely used in automation and automation Control of petrochemical plants, food machines, packaging machines, textile machines, machine tools, plastic machines, fitness machines, entertainment possibilities. Especially suitable for corrosion, moisture, dust, and other harsh environments, and frequent switching the occasion, AC contactor is updated alternative.
Packing include:
3 x Solid State Relay
- Product name: solid state module relay SSR-40DA, 3-32VDC/24-380VAC.
- SSR Application: with a switch no spark, no noise,high switching speed,anti-corrosion,moisture-proof,anti-vibration,long life.high reliability,electromagnetic compatibility and other characteristics.
- Solid state relay ideal for automatic process control application, a must component for temperature controller and other machinery control system.
- Especially suitable for corrosion, moisture, dust, and other harsh environments, and frequent switching the occasion, AC contactor is updated alternative.
- High reliabily, compact size, a great part for temperature controller and other machinery control system.
User questions & answers
| Question: | Can I used for vacuum motor |
| Answer: | As long as the vacuum motor does not drow more than 40 amp |
| Question: | Has anyone used a raspberry pi or arduino to control these via gpio |
| Answer: | Yes, it works fine in that context. I use it to switch a 110VAC bed heater for a 3D printer. Just connect the input + pin to your IO pin, and the input - pin to your Pi or Arduino's ground. |
| Question: | How much current will be drawn on input 24v dc |
| Answer: | It is 25ma, thanks. |
| Question: | Is there a minimum amp required? I am using 15 vdc/1000 mA and the light comes on but relay contact never engages |
| Answer: | I don’t have a spec sheet, but there is a small trigger current requirement. I recall something like 12v and 7.5 ma. I don’t know for sure |
CG Solid State Relay SSR-25DD DC to DC Input 3-32VDC To Output 5-240VDC 25A Single Phase Plastic Cover
Product description
Features:
Model:SSR-25DD
Current:25A
Input Control Voltage:3-32V DC
Output Voltage:5-240VDC
Frequency:50/60Hz
Net Weight:116g
Ambient Temperature:-20~+75℃
Single Phase Solid State Relay with LED indicator
1.Triac output, zero voltage open, zero off.
2.Optical isolation between input circuit and output circuit.
3.Inputs-between the output isolation voltage 2500V.
Application:
SSR series solid state relay with flame-retardant plastic housing, epoxy casting compound, wiring screw terminals with high structural strength,impact strength, vibration resistance, the input drive current small can be convenient and computer terminals and a variety of digital programmable circuit interface, widely used in automation and automation Control of petrochemical plants, food machines,packaging machines, textile machines, machine tools, plastic machines,fitness machines, entertainment possibilities. Especially suitable for corrosion, moisture, dust, and other harsh environments, and frequent switching the occasion, AC contactor is updated alternative.
- ♥【What You Get】Each package With 2 mini bag of thermal grease which apply on the back of the SSR to make the temperature dissipate faster.
- ♥ Product Name: solid state module relay SSR-25DD, 3-32VDC/5-220VDC ; Current & Frequency:25A,50/60Hz.
- ♥ Total size (approximate):58 x 45 x 32mm/2.3" x 1.8" x 1.26" (l*w*t); Net weight:116g; Material:metal, plastic, electronic parts.
- ♥ SSR Application: with a switch no spark, no noise,high switching speed,anti-corrosion,moisture-proof,anti-vibration,long life.high reliability,electromagnetic compatibility and other characteristics.
- ♥ Solid state relay ideal for automatic process control application, a must component for temperature controller and other machinery control system.
User questions & answers
| Question: | Will this relay work if the output voltage is at 80a but only 2volts? the relay says its rated for 5-220v |
| Answer: | Its the AMP draw you have to worry about. If your draw is at 80amps then make sure you use a 100AMP SSR.. Never run it to max. |
| Question: | Is this really only for switching dc at the output, or is that a mis-print? it lists a frequency range, which implies ac use |
| Answer: | This is for DC , there are versions that are AC . Just look for Solid state AC/ relay |
6PCS SSR-40DA Solid State Relay Single Phase Semi-Conductor Relay Input 3-32V DC Output 24-380V AC
SZCY LLC
- Product name: solid state module relay SSR-40DA, 3-32VDC/24-380VAC.
- SSR Application: with a switch no spark, no noise,high switching speed,anti-corrosion,moisture-proof,anti-vibration,long life.high reliability,electromagnetic compatibility and other characteristics.
- Solid state relay ideal for automatic process control application, a must component for temperature controller and other machinery control system.
- Especially suitable for corrosion, moisture, dust, and other harsh environments, and frequent switching the occasion, AC contactor is updated alternative.
- High reliabily, compact size, a great part for temperature controller and other machinery control system.
User questions & answers
| Question: | Do these switch on zero crossing or can they be used for phase control dimming |
| Answer: | It's not clear that they are in fact zero cross, I wouldn't modulate these for phase control dimming. The heat sinking is questionable at best. |
| Question: | Can these actually handle sustained 40a at 240vac? there seem to be many fotek fakes |
| Answer: | With a proper heat sink and thermal compound perhaps. But the price would suggest they may not be genuine. |
Product features
Application:
- SSR series solid state relay with flame-retardant plastic housing, epoxy casting compound, wiring screw terminals with high structural strength, impact strength, vibration resistance.
- Can be convenient and computer terminals and a variety of digital programmable circuit interface, widely used in automation and automation Control of petrochemical plants, food machines, packaging machines, textile machines, machine tools, plastic machines, fitness machines, entertainment possibilities.
- Especially suitable for corrosion, moisture, dust, and other harsh environments, and frequent switching the occasion, AC contactor is updated alternative.
Features:
- Model number: SSR-40DA
- Theory: Solid State Relay
- Input: 3-32 V DC
- Output: 24-380 V AC
- Rated operating frequency: 50 / 60Hz
- 1. Triac output, zero voltage open, zero off
- 2. Optical isolation between input circuit and output circuit
- 3. Inputs-between the output isolation voltage 2500 V
SSR-25DA Solid State Relay DC to AC (Input 3-32V DC Output 24-380V AC) with Heat Sink, 25A
DMWD
Product description
DMWD Low cost single phase solid state relay SSR-25DA
Input voltage 3-32V DC
Load voltage 24-380V AC
Load current 25Amp
25A 3-32V DC to AC solid state relay (SSR) features high structural strength, good impact resistance, and strong shock resistance. The SSR offers a reliable switching the commercial and industrial loads, such as computer peripheral interface device, printing machine, molding machine, food machine, packaging machine, and so on.
- Built in RC absorption
- Photoelectric isolation
- SCR output
- LED indicator for operation status
- Panel mount
- Zero-crossing switch type
- UL Approved, CE Compliant to EN60950-1
Note:
* When the load current is higher than 10A, a heat sink must be installed to the solid state relay, or the SSR relay should be mounted on a metal base plate with heat dissipation effect, and the thermal grease is applied between them.
* When the load current is 40A or more, a fan cooling radiator or water cooling radiator must be equipped.
* Heat sink is included.
Package Content:
1 x Solid State Relay
1 x All Aluminium Heat Sink
Size/Weight:
SSR(58x45x28mm/80g)
Heat Sink(78*50*50mm/80g)
Warranty:
Free new replacement in 5 years, Have faith in quality
- Model: SSR-25DA, single phase Solid State Relay 25A DC to AC control, UL Approved, CE Compliant to EN60950-1
- Input voltage 3-32V DC, Load voltage 24-380V AC, Max load current 25 Amp
- Rugged epoxy encapsulation construction, high isolation over than 50MΩ(500VDC), high dielectric over than 2.5KV, output snubber circuit protection
- No EMI/EFI & Low surge by Zero Cross Trigger method, specially suited to control sensitive, capacitive and Non-saturated inductive loads
- SSR switches use semiconductor component acts as a switch for the relay, no moving parts inside, no mechanical wear, no action noise, no mechanical failure, and high reliability
Solid State Relay SSR-40AA 40A AC to AC Input 80-250V AC and Output 24-380V AC (SSR-40 AA)
Jekewin
Product description
Specification:
This is solid state relay SSR-40AA.
Model: SSR-40AA
Input voltage: 80-250V AC
Output voltage: 24-380V AC
Output current: 40A
- SSR-40AA Solid State Relay 40A AC to AC
- Input: AC 80-250V, Load: AC 24-380V
- Material: Metal, Electronic Components
- Item size: 60*45*23mm
- Package include: 1x Solid State Relay
User questions & answers
| Question: | What is the amps draw on the input, will it excide 3amps @120vac |
| Answer: | I didn’t measure it but it was small. I can’t remember off the spec sheet but probably 500 milamps. |
| Question: | Relays says it accepts ac input. does bridge rectifier diode must be used |
| Answer: | No. This model accepts AC power on both the power and control sides, so no rectifiers are needed for proper operation. |
| Question: | What happens if the output voltage is less than 24V |
| Answer: | It won’t activate the relay |
| Question: | What is the difference between aa and da ssrs |
| Answer: | The input Voltage that controls the relay is 80-250volts AC on the AA and 3-32 volts DC on the DA |
Inkbird SSR Solid State Relay SSR 40DA for PID Thermostat Temperature Controller
Product description
Note: A heatsink must be used or it will get burned out.
For sale is a 40A Solid State Relay (SSR). It's good for heater, oven, or other appliance up to 3500Watt power consumption. Ideal for PID temperature controller.
Specification
Input: 3V-32V DC
Control: 24V~380V AC
Current: 40A
Packge:
1 x solid state relay 40A
- Input : DC 3-32V;
- Output : AC 24-380V
- Solid State Relay
- Type : SSR-40DA
- 1 x Solid State Relay
User questions & answers
| Question: | does it come with a heat sink |
| Answer: | This is a separate solid state relay. If you need a heat sink, you can click on the following link：https://www.amazon.com/dp/B01MCWO35P?ref=myi_title_dp |
| Question: | What is the minimum dC current required |
| Answer: | Not sure, but it’s in milliamperes. It’s more voltage dependent than current . |
| Question: | What gauge are the terminals |
| Answer: | The terminals are a screw down clamps with a 3.5mm max opening. The screw is 4mm shaft with a 7mm + phillips hex head. |
| Question: | What is the minimum volts ac needed to close the relay? i need something that will close when 1 to 3 vac are applied |
| Answer: | The minimum voltage is 3V DC. It is not designed for an AC input voltage of any type. |
TWTADE SSR-40 DD 40A DC 3-32V to DC 5-60V SSR Solid State Relay + Heat Sink
：TWTADE
Model: SSR-40DD Solid State Relay 40A DC to DC
Input voltage: 3-32V DC Output voltage: 5-60V DC
Heat Sink Mounting Thread Diameter (Approx.) : 0.5cm / 0.19"
Heat Sink Total Size (Approx.) : 8 x 4.9 x 4.9cm / 3.1" x 1.9" x 1.9" (L * W * T )
Package Content: 1 x SSR, 1 x heat sink
Notice Of Use
1. The current on the product is the maximum load current, not the rated current.
2. On the basis of the different of the load character,you should keep the different allowance on the level of the current when you choose the product.(When the load is resistive, the load current should be 1/2-1/3 times of the max load current .When the load is inductive or capacitive,like motor， transformer， the load current should be 1/4-1/6 times of max load current.)
