A reed switch is an electrical switch which can be operated by applying a magnetic field. The metal contact peddles are hermetically sealed in a tubular glass envelope filled with an inert gas. This makes the construction a spark free, explosion safe, electric switch. Reed switches are mainly used for switching lite control currents, which you find in relais, contact switches, airbags and ABS systems. 

Principle of a reed switch

The metal peddles are magnetizable, flexible and separated by a small gap. When a magnet is pulled away from the switch, the peddles will go back to their original position or vice versa.  

Laser adjustment of the peddle distance;
Because the correct peddle distance is crucial for the switch function, our vision system measures, at first production, the peddle distance.  Based on the opening found the precise correction by bending the peddles is then calculated.

A LASAG laser system shoots laser-spots, through the glass, on the individual reed-peddles whereby number, position, pattern and intensity of the laser-spots is precisely determined. The adjustment of the peddle distance is within ± 5µm. In a servo driven carrier 45 reed switches are trimmed ‘In fly’ . For the high positioning demand of the carrier a measuring system was used with a position accuracy of  ± 1µm.

To have a continuous production of adjusted switches the machine is operating with two complete lines.   

              The two individual positioning units

                             Transport tunnel for the exclusion of external light

                                   Precision handling unit for the carrier

Machine overview, left covered, right uncovered with laser unit (built in 2002)