SSR-40DD Solid State Relay | 3V-32V DC to 5V-200V DC | 40A

SSR-40DD Solid State Relay | 3V-32V DC to 5V-200V DC | 40A 

Product Overview

The SSR-40DD from Pro Tronix is a specialized relay built for Direct Current (DC) switching. While most standard SSRs are designed for AC loads, the 40DD model utilizes high-power MOSFET technology to toggle DC circuits between 5V and 200V DC.

This is an essential component for projects where a low-power microcontroller (like an Arduino or ESP32) needs to control a high-current DC device. Because it has no mechanical contacts, it eliminates the “arcing” often seen when breaking high-current DC circuits, making it significantly safer and longer-lasting than traditional electromagnetic relays.

Technical Specifications

Key Features

• DC-to-DC Specialization: Designed specifically for DC loads, preventing the “latching” issues that occur when using AC SSRs in DC circuits.

• Ultra-Fast Response: With switching times under 1ms, it is perfect for high-speed PWM applications like motor speed control or dimming high-power LED arrays.

• Maintenance-Free: No moving parts means no contact pitting or mechanical failure, even after millions of cycles.

• Safe Isolation: Provides full optical isolation between the sensitive control input and the high-power DC output.

Common Applications

• High-Power DC Motors: Controlling the speed or state of large 12V/24V/48V motors in robotics or EVs.

• Solar & Battery Systems: Switching heavy loads in off-grid solar setups or battery charging stations.

• Hydrogen Generators (HHO): Managing the high-current DC required for electrolysis cells.

• DC Heating Elements: Controlling 12V/24V heating pads or specialized industrial DC heaters.

⚠️ Maintenance Tip: High-current DC switching generates significant heat. A dedicated aluminum heat sink is mandatory for loads above 10A, and thermal paste should be applied between the relay and the sink for maximum efficiency.

You can see the rest of our available relays from here: Relay | Pro Tronix