Alcatel Business Systems

Roneo Alcatel Limited

Stephen C Barratt

David Anthony Gawler

Brian W Grant

Protection of electronic circuits from static electrical discharge is provided by utilizing a key mat, having key buttons moulded therein, of a key board for the circuits to provide an electrically insulating barrier to such discharges. The electronic circuits are housed in a housing having apertures through which the key buttons extend. Electrical discharge from a key button through the aperture in the housing to the circuits is prevented by forming the mat to have an extent sufficient to ensure that any discharge track is longer than that for a predetermined potential. Where the direct distance to a circuit is short the mat is formed so as to ensure a discharge track greater than the direct distance and of sufficient length. For this purpose the mat may be formed with an upstanding wall. A housing may have a cooperating wall to lengthen the air path.

Protection of electronic circuits

An electromechanical drive for a franking machine comprises a module in which an electic motor controlled by an electronic circuit formed on a printed circuit board is manufactured as a modular unit by mounting the motor, mechanical drive components and a position sensor on the substrate of the printed circuit board. This module is mounted on a further module consisting solely of mechanical components and the drive components of the two modules are thereby drivingly engaged. This construction leads to economies in manufacture and ease of servicing because no electrical connections are required between the modules and hence assembly and dis-assembly of the circuit board and mechanical component module are made easier.

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Hornchurch, United Kingdom

Stephen C Barratt