Drives and Controls Magazine
Touch sensor replaces pushbuttons
Published:  27 June, 2012

The sensor specialist ifm electronic has developed a capacitive sensor that can replace conventional pushbuttons in applications such as machine start/stops and door openers. The IP67-protected KT sensors can detect touch through non-metallic materials such as plastics or glass, and have no moving parts that could wear out or break.

Users simply touch the exterior panel to produce a 300ms output pulse. Self-adjusting dynamic switching ignores build-ups of dirt, water or ice. The 100mm-diameter, 11mm-deep sensors need no force to activate them and are ideal for repetitive operations. A ring of green LEDs shows when the sensor is powered, while red LEDs indicate that it is activated. The switch can be ordered with a surround in a choice of colours, or with no surround. There are versions with positive or negative switching outputs, and with 2m cables or in-line M8 plugs on shorter leads.