It consists of an Arduino-compatible Shield with a 12v Relay. It also includes a 2-position DIP Switch so that you can add some options to your program. This relay kit will plug directly on top of your Arduino UNO.

Arduino UNO is not Included

The Relay is controlled by the Arduino Digital outputs and the DIP Switches are connected to the Arduino Analog inputs. There is a 2-pin screw terminal for an external 12vdc to power the relay. This 12vdc is also connected to the Arduino VIN input so that both units can be powered by the 12vdc coming in. This means you can write your program, load it into the Arduino, and then relocate both units to anywhere that you need. They do not need to be connected to the computer once it is programmed. The required external 12vdc power supply is not included.

The Relays are an 833H series SPDT relay with Form 1C contacts rated for 7 Amps @ 250VAC. It has a 12VDC coil. Each set of Relay contacts are available at a dedicated 3-pin screw terminal. The available contacts are the Common (COM), NO (Normally Open) and NC (Normally Closed). This means that the circuit can either turn devices ON for a set time period or turn those devices OFF for a set time period.

You can control many different 120 VAC devices, such as your Christmas lights, sprinkler system, garage door, etc with the program you write using your Arduino UNO. Have them alternate back and forth for a nice effect.

This kit is now offered with a "Built & Tested" option for those that do not want to build it themselves.

This is one of the first practical applications for Arduino that you will find. You can select from 1 to 4 Relays, the default selection is one Relay.

You will get a schematic and all of the parts to assemble a working unit. This kit does not include the tools you will need to assemble the circuit. You will need tools such as a soldering iron, solder, wire cutters, etc. Below is a detailed introduction to component identification and kit assembly.