SSR-40DD 40A Solid State Relay DC to DC

This solid state relay switches DC loads up to 60 V and 40 A via a DC control signal of 3 to 32 V, for example from an Arduino. It switches via power electronics instead of mechanical contacts. This means no switching spark and no mechanical wear, even with fast switching. Integrated optocouplers provide the galvanic isolation.

Important: Only suitable for DC loads, not for AC. The relay must be mounted on a heat sink or a metal mounting plate so that the heat is dissipated and it does not overheat. Input and output are polarised, the terminals are labelled.

Recommended Accessories:

Features:

No switching spark and no mechanical wear
Galvanic isolation by integrated optocouplers
Suitable for fast switching of loads
Screw terminals for input and load
Metal plate on the underside for mounting on the heat sink

Application Examples:

Switching DC loads up to 60 V via a microcontroller
Frequent and fast switching without mechanical wear
Replacement for mechanical relays with DC loads

Connection to 5 V Logic (for example Arduino UNO):

Terminal 3 (+) to a digital output, for example pin 8
Terminal 4 (−) to GND
Output HIGH: relay on. Output LOW: relay off
Load: positive of the source to terminal 2 (+), terminal 1 (−) to the load, load to negative of the source

Connection to 3.3 V Logic (for example ESP32, Raspberry Pi):

Terminal 3 (+) to a GPIO, terminal 4 (−) to GND
GPIO HIGH: relay on. GPIO LOW: relay off
3.3 V is only just above the lower input limit of 3 V
Before connecting, measure the input current: GPIO pins supply only little current (Raspberry Pi: at most 16 mA per pin)
Load as with 5 V logic