Speed Switches are divided into:
• mechanical speed switches (centrifugal force switches, type designation starts with FS ..), which are used for safety monitoring of speeds in drive engineering, regardless of the control system, and
• electronic speed switches (type designation starts with ES ..) that use a rectified voltage (own PSU or auxiliary supply) and one or more potentiometers which are set so that a one or more relays is/are operated when the speed limit(s) is/are reached.
• digital speed switches (type designation starts with DS ..) that use HTL or TTL signals from a rotary incremental encoder, independently of the drive control system itself, and generates an output signal for each one of three separately adjustable speeds. This feature can be used to implement a safety function or quality-control.