Microcomputer-controlled circuit tester

In a system for the programmed control of a plurality of loads provided with respective operating circuits including drivers individually associated therewith, and computer means for cutting said drivers in and out according to a given program,

• the combination therewith of testing equipment for individually checking the integrity of any of said operating circuits, said equipment comprising:
• a generator of a pulsating unipolar test voltage connectable to a common terminal of said operating circuits in parallel with a capacitance chargeable by said generator through a unidirectionally conductive connection;
• sensing means connected across said capacitance for detecting the magnitude of a voltage difference developed thereacross, said sensing means having an output connected to said computer means;
• selector means, connected to said computer means, for identifying a driver of an operating circuit to be checked, said computer means being responsive to said selector means for activating the driver so identified whereby the voltage difference across said capacitance decreases upon conduction of the selected operating circuits;
• switch means operable to cause said computer means to emit a series of brief activating pulses, of a duration insufficient to operate the associated load, to a driver identified by said selector means, said computer means being responsive to an output signal from said sensing means resulting from a significantly reduced capacitance charge to terminate the emission of said activating pulses;
• and
• indicating means operable by said computer means in response to an output signal from said sensing means to register the state of conduction of the selected circuit.