Fotek SSR-25DA Solid State Relay

The Fotek SSR-25DA Solid State Relay is a robust, optically-isolated DC-to-AC switching module capable of handling 25 Amps at 24–380V AC, making it a go-to solution for noise-free and durable switching applications. Unlike mechanical relays, this solid state relay (SSR) ensures silent operation, faster switching, and greater longevity, making it perfect for industrial-grade and home automation environments.

Internally, the relay features a zero-cross detection circuit, which minimizes electrical noise during switching and ensures minimal wear on connected appliances. The input control voltage ranges from 3V to 32V DC, making it compatible with most logic-level control boards like 🔗 Arduino, 🔗 ESP8266/ESP32, Raspberry Pi, and PLC systems.

🔧 Technical Specifications:

• Model: Fotek SSR-25DA

• Control Voltage (Input): 3V–32V DC

• Load Voltage (Output): 24V–380V AC

• Max Current: 25A

• Switch Type: Zero Cross

• Insulation Resistance: >100MΩ (500VDC)

• Leakage Current: ≤ 2mA at 380VAC

• Response Time: <10ms

• Dielectric Strength: ≥2500VAC (input/output)

• Heat Sink Required: Yes (for loads >10A)

• Mounting: Panel mount with screw terminals

• Indicator LED: Yes (control signal)

💡 Key Features & Benefits:

• ✅ No mechanical parts – no noise, no spark, long lifespan

• ✅ Ideal for high-speed switching applications

• ✅ LED input signal indication for easy diagnostics

• ✅ Designed for AC power control in automation projects

• ✅ Compact form factor for easy enclosure fitting

• ✅ Compatible with 3.3V and 5V microcontroller signals

• ✅ Optical isolation improves system safety and reliability

⚙️ Common Applications:

• Industrial equipment automation

• PID temperature control systems

• Smart HVAC solutions

• Home appliances switching

• 3D printers and heating element management

• Robotics and DIY IoT projects

• Arduino and 🔗 Raspberry Pi controlled power systems

🔌 Microcontroller Compatibility:

This SSR is ideal for integrating into projects using Arduino, ESP8266, ESP32, STM32, and Raspberry Pi, making it a versatile choice for students, hobbyists, and professionals working with smart control systems, especially in STEM learning environments.

⚠️ Precautions for Safe Use:

• Always attach a heat sink or active cooling fan when using high-current loads.

• Do not exceed the rated voltage and current limits.

• Use a snubber circuit or external protection if controlling inductive loads (motors, transformers).

• Ensure proper insulation and mounting to avoid short circuits.

• Avoid installing in moisture-prone or unventilated enclosures.

📍 Available Now at ElectroWay — your trusted electronics and robotics partner based in Johar Town, Lahore. We offer the highest quality components and same-day shipping across Pakistan.

🎥 Learn More – Video Tutorial:
How to Use Fotek SSR-25DA with Arduino (YouTube)

🔗 Helpful Links & Related Products:

• ESP8266 WiFi Modules

• Arduino Boards

• Microcontroller Accessories

• Modules & Sensors