SunFounder 2 Channel DC 5V Relay Module with Optocoupler Low Level Trigger Expansion Board Compatible with Arduino R3 MEGA 2560 1280 DSP ARM PIC AVR STM32 Raspberry Pi

Bought this relay board to make a remote control for physically disconnecting a comm bus at a remote site to allow for troubleshooting. It works well being controlled with an arduino.

Recommended!

The relay works very well with Arduino. Simple wiring and the relay is operating properly.

This is a good relay board, easy to use and does precisely what I wanted it to do. Wired it to an Arduino that I had assigned relay controls to the relevant pins, was able to correctly control all 4 relays as desired. I misinterpreted the drawings at first and thought that if the three contacts on each relay are A/B/C, that A/B were connected with no power, and A/C were connected when the relay was powered. Well it turns out I'm a dork, A/B are connected with no power and B/C are connected when the relay is powered. Once I figured that out, making everything work was super simple. Small bank of LED indicates when each of the 4 relays is powered, since you can hear the clicking but it's nice to have visual feedback about which relay/s made the noise. Good relay shield.

The description claims 20mA per relay but I am measuring 60mA for each on relay (just on the JDVcc/5v side alone--I'm using 3.3v for the control side). The data sheet for the relays says 90mA each (at a full 5 volts, which these probably aren't seeing in practice). So, just beware, if all 8 relays are on, the relay side alone will pull 480-720mA, not the 160mA they imply. Also, the relays jitter while my NodeMCU powers up (partly an issue with the NodeMCU, and partly because the relays inputs are inverted), so I have added a high-side power switch controlled by one of the few stable GPIO pins, which allows me to keep the relay side of the board powered down until the NodeMCU is ready and stable. I assume the rPi would have a similar issue. This was a pain to do. (But it's only a 20 cent part, so it would be a great additional feature on the board if they built it in...)

If you are truly looking to decouple and isolate the device controlling the relay (such as an Arduino, etc) from the relay coils to provide true optoisolation, you must connect it in the following way: Remove the jumper from the JDVCC pin, connect power from a separate 5v power supply to the JDVCC pin and ground from the separate 5v power supply to either of the Gnd pins. Next connect the 5v pin from your controlling device (arduino) to the VCC pin on the 10-pin header of the module, and connect your I/O pins from the Arduino to the 8 control pins. The opto-isolator will get the 5v signal from the Arduino, and the Ground from the Arduino when you perform a digital write LOW on the I/O pin, completing the circuit, and that control circuit is completely isolated from the relay coil power circuit. The gotcha with this board is that the Gnd pin on the 10-pin header and the Gnd pin on the JDVCC/VCC/GND header are actually connected on this board. This means if you connect your Arduino Gnd to either of the Gnd pins on the board, you have now tied your Arduino to the separate 5vdc power supply (which you might not want to do). With all 8 relay coils activated, the board draws 472mA of power - about 50-55mA per relay.

This module is perfect! It comes all soldered and has the screw-in terminals. Like almost all relays of this type it can't handle more than 10 A. In the rest of the world that would be no problem since 230 V breakers trip at 10 A. But in North America, with 15 A and 20 A circuits, this is not going to work. That limits you to devices 1200 W or less. My first project with it is a system to water plants. The pump only requires 4-12 V and probably a few hundred milliamps. By the way, if you want to power bulbs or for many other applications, I recommended using DC voltage. The bulbs will light up just the same, but it will be much less dangerous than dealing with AC. ONE PROBLEM: It lacks labeling of the relay terminals. NO Normally Open, C Common, NC Normally Closed are not printed. ONE GIANT ADVANTAGE: This module compared to others is great because you supply 5V to it through a separate pin, so you don't have to provide the required current on the input pin. The module does that for you. Many boards out there will have only an input pin, which you can't use directly, you'll have to build the missing circuitry so you can control the relay with your Arduino or whatnot. Plus some boards are missing the very important diodes! It also has one status LED per relay so you know what's going on at all times. Note that it is active low.

SunFounder 5V Relay Shield Module for Arduino UNO 2560 1280 ARM PIC AVR STM32 (4Channel) I am extremely happy with this board. It works flawlessly with the Arduino. It is responsive and VERY easy to use. Remember though, that its logic is Active Low, so when power is first applied from the Arduino, the low state of the pins causes the relay to turn on until the Arduino has time to set them to active high, thereby turning them off. I solved this problem using a 2N2222 transistor and a 1k Ohm resistor between an Arduino pin and the 5 volt input to the relay. Now, when the Arduino powers on, there is NO power to the relay board UNTIL the program tells it to do so. GREAT PRODUCT - HIGHLY RECOMMENDED!

I spent a couple of weekends trying to get one working for the Arduino with no success, This came plugged into to Pi and heyy presto. No fiddling around nothing, works like a dream too.

Este Shield es de muy buena calidad y además facilísmo de utilizar: Conectas Vcc y GND y luego las salidad de tu arduino(u otro microcontrolador) a las cuatro entradas disponibles. Cabe destacar como otros muchos usuarios, que la lógica es invertida; es decir, cuando la salida del arduino es HIGH, el relé esta apagado y viceversa.

Llegada en el tiempo estimado. Producto nuevo , todo correcto.

These have worked perfectly with a rasberry pi to make a garage door controller

I am using these relays to control LED strip lighting. The controller operates on 5VDC and the lights require 12VDC. These relays provide a perfect solution. The optocouplers provide an added level of isolation. The relay coils operate on low current 5VDC. The output contacts can handle high current loads of different voltages. There is a set of NO and NC contacts for each relay. Each relay is operated independently. I recommend this product for anyone that requires isolation between the controlling circuit and the output load.