The SPGA series from ALPS, a tactile switch that needs no battery or accumulator thanks to energy harvesting techniques is available from distributor Avnet Abacus. Based on magnetic induction technology, the modules measure just 17.5 x 23 x 17.9 and supply 170 µJ with every touch.
That's enough energy to control ceiling lights, pond pumps, door operators or similar via a low-power radio protocol such as EnOcean.
A 3.3mm switching distance means the SPGA series can also be used to detect the opening and closing of doors, drawers and cupboards.
One advantage of this series over conventional detector switches is its ability to detect the direction of movement.
When pressed, the switch generates a positive voltage pulse; when released, a negative one.
This feature, coupled with a minimum lifetime of 1 million switching cycles, also makes the series suitable for position detection in the field of robotics, for example.