Automatic Machine for Testing Capacitors and Resistance-Capacitance Networks

T h e capacitors discussed in this article are the ordinary broad limit units made with windings of paper and metal foil, packaged in a metal case. T h e y include both single and double units in a package, connected to two, three, or four terminals. T h e networks consist of a capacitor of this same type connected in series with a resistor. T h e testing requirements for capacitors include dielectric strength, capacitance, and insulation resistance. These same tests plus impedance measurements are specified for networks. In general, requirements of the kind involved here could be adequately verified by statistical sampling inspection. However, in equipment as complex as automatic telephone switching frames, even the minor number of dielectric failures that would elude a properly designed sampling inspection would result in an intolerable expense in the assembly and wiring operations. While engineering considerations thus called for a detailed inspection for dielectric breakdown, it was recognized that detailed inspection of the other electrical requirements could be obtained at 110 additional expense for labor with automatic testing machines. 1179