Microwave Body Sensor
The microwave body sensor has been well documented on the internet and tested multiple times. How it works remains a mystery to many, but the set up of this device is very simple. the tiny circuit board has a regulated output, a ground, and a switched live.
When the microwave sensor detects a body within range it will power the switched live with a low current.
The unit will work approximately 20 feet away, and due to the nature of microwaves will work through walls.
In this project the switched live powers a transistor which in turn switches on a standard 555 set up flashing a red LED.
The entire project is mounted tightly into a small project box with almost the entire space occupied by 3 x AA 1.5v batteries. The microwave circuit is shoehorned down the side of the battery compartment.
In tests the microwave circuit can just about power a 555 circuit directly, but the output is brighter and sharper with a switched transistor.
This unit placed on a shelf will detect movement anywhere in the room, or the room above it.
When powered up the unit takes around 5 seconds to stabilise itself during which time the output is switched on.
The Microwave sensor itself draws very little current, with the majority of the current in this circuit being drawn by the 555.
