Proximity Switch

Proximity Switch is a momentary switch. It is used to determine how close an object or the proximity of an object. When any particle comes beside this switch sensor, it gives a signal by making the switch either ON or OFF. So this switch is used to detect the presence of an object. Proximity switch consist a sensor circuit and a driver circuit. According its sensing type, there are three types of proximity switch. They are-

1. IR or Infrared Ray Type Switch
2. Inductive Type Switch.
3. Capacitive Type Switch

Besides these types there are also ultrasonic, photoelectric, magnetic proximity switch.

Front View of Proximity Switch

IR Type Proximity Switch

With the help of infrared ray these types of proximity switch works. Both metal and non-metal object can be detected by these types of switch. IR Switch has very high sensing distance comparing inductive and capacitive switch.

Inductive Type Proximity Switch

With the help of inductive field inductance these types of proximity switch works. Only metallic object can be detected by these types of switch. Inductive switch has less sensing range. That is 30-40mm

Capacitive Type Proximity Switch

With the help of build in capacitance these types of proximity switch works. Only non-metallic object can be detected by these types of switch.

Side view of a Proximity Switch

Proximity Switch Connection

To use proximity switch we maintain international color method to its three pin connection. According this method-

• Brawn color is always positive input.
• Blue color is always negative input.
• Black color is output.

Bottom View of Proximity Switch

Proximity switch takes 24V DC supply to be active or come in operation mood. To get the output of the switch, we get positive output from the output terminal and the negative or ground terminal from the negative terminal of proximity switch.

Written

Jeion Ahmed