Apparatus having a plurality of multi-position switches for automatically testing electronic circuit boards

Claim 1

Apparatus for automatically testing electronic circuit boards constituted by a plurality of discrete components arranged thereon in a predetermined configuration and having a plurality of connecting positions arranged in a predetermined configuration for making electrical connections to said components, said apparatus being capable of detecting and identifying at least a particular one of said components which is defective, said apparatus comprising: plate means having a plurality of resiliently biased contacts disposed in the same configuration as the connecting positions of the board to be tested, removable insulating mask means constructed to be disposed over said plate for selectively exposing certain of said contacts, the exposed contacts corresponding in configuration to the connecting positions on the board to be tested, a different mask being provided for each different type of board to be tested, manually controlled means for moving said contacts and said mask against the said connecting positions corresponding thereto, a first source of signal voltage for producing an output of a value sufficient to cause said components to perform their respective circuit functions, a second source of signal voltage for producing an output of a value relatively less than the value of first said output, means for measuring electrical quantities and sensing the electrical conditions at said contacts, common bus conductor means, a plurality of first multi-positioned switches, each said first switch having a movable common terminal connected to a respective one of said contacts and having a plurality of selectable terminals, one of said selectable terminals of each of said switches being connected to said measuring means, at least another of said selectable terminals being connected to said common bus conductor means, at least a second multi-positioned switch having a common terminal connected to said common bus and having one selectable terminal connected to said first source and at least one other selectable terminal connected to said second source, and means for selectively coupling said second switch to said first and second sources in a manner as to actuate each said component individually and in succession, said coupling means acting to connect said second source to said common bus followed by said first source and said coupling means including means for selectively connecting said measuring means to individual ones of said contacts over selected ones of said first switch means and others of said contacts to said common bus over others of said first switch means.