8 Channel Shield... how?

Hello everyone,

I have just received a 8 Channel relay pcb bought on ebay for just 8£ (http://tinyurl.com/7sjtbw8), but I am not too sure how to connect it up with arduino. I have used relays before but i just want to be sure not to blow anything so… would anyone give me a hand with this?

The 10 pins on one side are numbered 1-8 (arduino pins i guess) and a gnd and a vcc (how much power would this need?)

I need to connect various radios to power them on and off (via software). They are both dc powered (9, 12 volts), both mains ac (220).

Every advice would be very welcome! Thanks a lot!

Photo on 2012-05-10 at 15.21 #2.jpg

Photo on 2012-05-10 at 15.21 #3.jpg

Look at the pin strip and the labels on them. It is too small to see in the photograph.

Basically you will need to connect power and ground to the strip, and then the arduino outputs to the pins. The screw connectors on the other side go to the things you want to switch on and off.

You are going to have to play with it a bit. What kind of current do you need to source or sink to make the relays work? Can you show us a top view of the board? What part neumber is on the board? what manufacturer? If the board has a part number you might try searching for that and see what pops up.

I tried looking for it but it doesn't really come up with anything. It needs 5 volts to switch the relays on and off.. or at least that's what it said on the ebay page.. please have a look: http://tinyurl.com/7sjtbw8

on the relays it says Songle: 10A 250v AC, 10A 125v AC, 10A 30v DC, 10A 28V DC. So at least I should be sure that it works well with AC right? What I don't understand is why there are three screw connectors for each relay.. what's in the middle?


For those interested I found a nice tutorial here: http://www.hobbyist.co.nz/?q=interfacing-relay-modules-to-arduino . My shield does looks exactly the same except that I have 8 relays instead of 4. Job done!

Yours is a little different than the board in the tutorial because yours has the ability to enable optical isolation.

It sounds like what Terry's YourDuino sells. See if this wiki helps.

Got an Ohmmeter? those 3 pins MIGHT be common, normally open and normally closed. The label suggests that the 2 outer pins are Normally open.

According to the info an the selling page it requires 15 - 20 mA to operate each relay. Gnd to Arduino Gnd, Arduino output to Relay board input.