Signal Input Devices

Proximity sensors

These are in three types. They are capacitive, inductive and optical. Capacitive sensors are used to sense according to material property. To operate inductive sensors is used magnet. Inductive types are widely used with actuators. Because permanent magnets are included in one side of cylinders. Optical type is more familiar to us. It is sensitive to light intensity.

Push buttons and limit switches

Push buttons are widely used to give signals for control systems. Mainly push buttons are two types which are normally open and Close buttons. These are applying to switch panels of control circuits. By using normally open type push button can be given start signals for systems. Similarly close button can be used to stop purposes.

Limit switches are applied to instead of sensors. It works by touching its roller or relevant part. Accuracy is depending on limit switch types. Some one works micrometer distances. Reliability of limit switches are more higher than sensors. Because sensors may be week in dust areas but limits switch are not like that they can apply very robust areas in industry.