Electrostatic charge earthing wristlet - is used in MOS modules mfr. and has resistor limiting rate of discharge from operative to earth

摘要

When MOS or CMOS modules are to be assembled, they may be damaged even by electrostatic charges produced by the operators moving relative to plastics chairs. To prevent this damage, the operator wears on a wristlet a metal plate (2) which passes any electric charge through a cable (3) and a current-limiting resistor in an insulated box (6) to earth. A clip (13) connects the cable to any safe earth. The safe operation can be checked by an insulated housing (15) containing a battery, with the negative pole earthed through a cable (23). When the wristlet is hung over a hook (16), a connection is made to earth and the instrument (17) indicates whether the correct resistance is present.