Suffolk-based electronics manufacturer Herga Electric has developed a novel solution to the problem of sealing switches for use in harsh environments or areas where there is a risk of explosion. The Freemount magnetic switch eliminates altogether the need to make a hole through a panel, reducing sealing problems and making installation possible in areas where a switch could not previously have been fitted.
The switch operating knob, which is available in rotary or push-button forms, glues to any appropriate surface using a high strength marine adhesive. An electronic control module is then fitted to the other side of the panel up to 80mm away and uses giant magneto resistance (GMR) technology to detect the orientation of a magnet inside the operating knob. The device is self calibrating and has been designed to automatically switch off in the event of damage or power failure. Installation is possible on either side of any non ferrous surface up to 80mm thick.
Richard Chatham, Herga's managing director, says that applications for the new switch design, for which the company holds a patent, are emerging all the time. Applications so far identified extend beyond use in wet or unpleasant environments to include the control of kitchen appliances - where controls can be mounted neatly to expensive and difficult to cut worktop materials such as marble - and even to use of the switch as a door security device. In the latter case the operator unit would be carried as a key and held against the door to trigger the electronic unit behind at an unmarked point known only to authorised personnel. "The most exciting thing about this technology is that I'm sure we have not yet identified its biggest application areas," says Chatham