Two transistors with a common collector configuration and connected in a cascaded form constitute a Darlington Pair. While Darlington pairs can be made on a [[wysiwyg_imageupload::]]breadboard using a few electronic components, there are IC available that work as them and thus aid in making a circuit simple and easy to be operated.A darlington pair has various applications associated with it and one of them is to use it as a switch. As the transistor’s collector current is proportionally limited by its base current, it can be used as a current-controlled switch. This simple project can be used in various application like alarm circuits, in electronics control circuit to on and off the device.