Photocells and Motion Sensors are Electronic Devices you can use to Manage Indoor or Outdoor Lighting. The Main Difference Between Photocells and Motion Sensors is that the Former Detects change in light Levels, and The Latter React to Physical Movement. Movement in the Detection area Changes the Reflected Signals and Activates the Sensor. They also save Energy by Turning Themselves off when Light is Unnecessary. Many Motion Sensors use a Combination of Detection Methods to Provide enhanced Coverage and eliminate false positives. The adjustable timers built into some Sensors let you Control how long the Attached Lights Remain Active after it Detects Motion.

An SPST (Single Pole Single Throw) Switch is a Switch That only Has a Single Input and can Connect Only to one Output. This means it Only Has one Input Terminal and Only one Output Terminal. A Switch is a Mechanical or Controlling Device That Changes the Flow of Current Direction or Interrupts the Flow of Current Within a Circuit. Single Pole Single Throws (SPST) is Perfect for on-off switching. When the SPST is closed, the Circuit is Closed and the light from the lamp switches on. When The Single Pole Single Throw (SPST) is then opened, the light from the lamp goes out and the Circuit is off.