Electronics-Salon 2 DPDT Signal Relay Module Board, DC 12V Version, for Arduino Raspberry-Pi 8051 PIC.

I use them for my model railroad signal system. Thes are terrific for automation, and I have several! Excellent reliability!!

I hooked it up and saw an very small print on the relay that it is not usable for an inductive load. It is a great little board, well made and compact it would work as a logic switching device or a resistive load. It is not usable for switching an electric motor. I wanted to use it for my electric scooter to control the brake solenoid but that load is very inductive so the unit will not work. I wish the Amazon info stated that before I bought it and installed. it.

Use the 2 relay card with my model train turn-out (switch track). Straight is one relay and turned is the other. 2 elec isolated relay contacts, one signal lights and the second for track power. Work good. Only a 4 star because NO written instructions. May have killed one figuring out the "+" and "-".

This is the 12v version - will never work with Pi or other controllers without another relay driving it!

I needed to automate directional control of two 24V linear actuators simultaneously. Using this unit I was able to wire it safely so that there is no possible state where voltage can be applied both ways at the same time. If both relays are off, no current passes. If both relays are on, no current passes. Only one or the other being on while it's mate is off allows current to flow, guaranteeing safe application of power.

The relays work as expected, but the absolute lack of any kind of spec sheet was disapointing.

The relay is was what I needed for my application. I used the relay to automatically switch the solar power via solar battery function on my vintage fluorescent landscaping light to be powered from my 12 volt landscaping power supply via (12 volt - 5 volt converter). During the day the batteries charge and keep a charge at night. In case of a power outage, the relay switches the light so that the batteries are powering the light.

Plenty of room for mounting hardware.Good documentation.These boards are a little more expensive, but you get what you pay for.I would buy it again.