Product Description
This 2-Channel Solid State Relay (SSR) is a versatile and reliable switching module designed for safely controlling AC loads using low-voltage DC signals. It is an ideal solution for applications requiring electrical isolation between the control circuit and the load circuit, such as in home automation, industrial control systems, and IoT projects.
The module supports a wide input control voltage range (5V, 12V, or 24V DC) and features a selectable High/Low-level trigger, offering flexibility for different microcontroller platforms (like Arduino, STM32, PLC) and control logic requirements. Each channel can independently switch AC voltages up to 240V, making it suitable for controlling lights, heaters, motors, and other AC appliances.
Built with optocoupler isolation, it ensures enhanced safety by preventing high-voltage interference from damaging your low-voltage control circuitry. The compact design, screw terminal connectors, and LED channel indicators make installation and operation straightforward for both hobbyists and professionals.
Key Features
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Dual-Channel Design: Control two independent AC loads with a single module.
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Wide Control Voltage: Compatible with 5V, 12V, and 24V DC control systems (jumper selectable on some models).
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Selectable Trigger Mode: High-level or Low-level trigger can be chosen via a jumper to match your control signal logic.
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Optocoupler Isolation: Provides electrical isolation between input and output, protecting sensitive control circuits.
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Zero-Crossing Function: Reduces electromagnetic interference (EMI) and inrush current, extending the lifespan of connected loads.
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LED Status Indicators: Each channel has an LED to show the switching status.
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Screw Terminal Connectors: Ensure reliable and secure wiring for both control and load connections.
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Compact & Durable PCB Design: Easy to integrate into control panels and enclosures.
Main Parameters
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Channels: 2
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Control Voltage (Input): 5V / 12V / 24V DC (Selectable)
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Trigger Level: High or Low (Selectable via jumper)
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Load Voltage (Output): 24V ~ 240V AC
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Maximum Load Current: 2A per channel
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On-state Resistance: < 30mΩ
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Isolation Voltage: 2500V RMS
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Dimensions: Approx. 78mm x 55mm x 20mm (L x W x H)
Q: What is the main advantage of a Solid State Relay over a mechanical relay?
SSRs have no moving parts, resulting in silent operation, faster switching, longer lifespan, and no contact arcing. They are ideal for high-cycle-count applications.
Q: Can I use this to control a DC load (like a 12V DC motor)?
No, this specific model is designed only for switching AC loads. The internal thyristor/TRIAC circuitry requires an AC waveform to turn off. For DC loads, a DC-output SSR is required.
Q: How do I select between High-level and Low-level trigger?
The module has a jumper pin for each channel. Placing the jumper over the “H” pins sets it to High-level trigger (the relay activates when the control signal is at logic HIGH/VCC). Placing it over the “L” pins sets it to Low-level trigger (activates when the signal is at logic LOW/GND).
Q: My microcontroller is 3.3V or 5V. Can I use it with the 12V control version?
The control signal (INpins) is typically isolated and can often accept a lower voltage logic signal (like 3.3V or 5V) even if the module’s VCCis 12V, as long as the “High” signal voltage is sufficient to trigger the internal optocoupler. However, for guaranteed compatibility, it is best to match the control signal voltage with the module’s VCC or consult the datasheet.
Q: What does "Zero-Crossing" mean, and when shouldn't I use it?
Zero-crossing turns the load on/off only when the AC voltage wave crosses zero volts. This minimizes electrical noise but introduces a small delay (up to ~10ms). Do not use it for applications requiring instantaneous switching, like phase-angle control for dimmers.
Q: Can I use this to control a large appliance like a water heater or air conditioner?
No. The maximum current rating is 2A per channel (~480W at 240VAC). It is designed for small to medium loads. For high-power appliances, you must use this SSR to drive a larger contactor that is rated for the required current.
Q: Is a heatsink required?
For loads below 1A, a heatsink is generally not needed. For continuous operation near the maximum 2A rating, mounting the SSR on an aluminum heatsink is strongly recommended to prevent overheating.
Q: Is this suitable for business/industrial purchasing?
Yes. This industrial-grade SSR module features robust isolation, stable performance, and screw terminals for reliable connections, making it suitable for prototyping, OEM integration, and light industrial control panels. Bulk pricing is available for business customers.
