Magnetic Switch

      Here is a simple Electronic Switch which can be operated by any Magnetic Field.  With little modification It can serve purpose of REED Switch just by adding a Relay Module. It can not directly drive electrical loads since their output drive capabilities are very small around 10 to 20mA, in that case either You can use a relay or semi-conductor device like transistor, SCR etc which will act as current amplifier.
      For the simplicity of the circuit I have used few components. In this circuit I have used Hall Effect Sensor, one LED and a 9 Volt battery. 5 Volt is enough for the circuit to operate. In market you will find two types of Hall Effect Sensor, Latching and Non-latching Sensors. In Latching type sensor, output state does not change even when you pull magnet away. In this project I have used Latched Hall Effect Sensor US1881. A electromagnet can also be used to control the circuit from a remote point.