Relay not working

Other Hardware Motors, Mechanics, Power and CNC
1

I am having trouble getting a relay to work. Here is the setup:

Relay:http: yourduino.com/sunshop2/index.php?l=product_detail&p=181

Arduino UNO:

Sensor Shield: http://yourduino.com/sunshop2/index.php?l=product_detail&p=2

Following these directions: http://arduino-info.wikispaces.com/ArduinoPower#ACDC

I have the Arduino UNO and a Sensor Shield attached to it. Using a three wire cable I have attached the relay.
I run the BLINK program and the LED on the Ardunio and the Relay blink according to the program. The problem is I do not hear the relay switching and after connecting a device to the relay it is clear it is not switching. The connection in the relay is always closed.

I have attached photos of the setup. Any help would be great!

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photo 2.JPG

photo 3.JPG

2

There seem to be a lot of opportunities to connect that cable onto the wrong connector.

Is it possible there is an error in the instructions?

Have you a power supply for the relay?

I would change the blink sketch so it is on and off for, say, 20 seconds each and check with a multimeter to see if the voltage on any of the connector pins is changing. Be careful not to short the multimeter probe across two connector pins.

...R

3

Thanks for the quick response! It was the lack of a power supply that you suggested. It works now! I had the cables connected in the wrong location.

4

Actually, the relay board and the sensor shield aren't pin compatible.
You connected a cable that was wired corresponding to the sensor shield, but not to the relay board.
The red and white wires should be exchanged at the relay board.