Automotive testing apparatus for measuring voltage, frequency, dwell time, current and impedance

Claim 1

IN AN ELECTRICAL TESTING APPARATUS, A PLURALITY OF TEST CIRCUITS, A MULTISCALE METER COMMON TO THE PLURALITY OF TEST CIRCUITS AND OPERABLE WHEN SELECTIVELY SWITCHED TO ANY ONE OF SAID CIRCUITS TO PROVIDE A TEST READING; SAID TEST CIRCUITS COMPRISING A VOLTAGE MEASURING CIRCUIT INCLUDING SAID METER FOR PROVIDING AN OUTPUT SIGNAL IN ACCORDANCE WITH THE MAGNITUDE OF AN INPUT VOLTAGE; A SIGNAL FREQUENCY MEASURING CIRCUIT INCLUDING INPUT CIRCUIT MEANS ADAPTED TO BE COUPLED TO A SOURCE OF RECURRENT SIGNALS, PULSE PRODUCING CIRCUIT MEANS FOR PRODUCING A SERIES OF CONSTANT ENERGY PULSES IN RESPONSE TO SAID RECURRENT SIGNALS HAVING A FREQUENCY WHICH VARIES IN ACCORDANCE WITH THE FREQUENCY OF THE RECURRENT SIGNALS, AND INTEGRATING CIRCUIT MEANS INCLUDING SAID METER FOR INTEGRATING SAID CONSTANT ENERGY PULSES AND PRODUCING A READING ON SAID METER IN ACCORDANCE WITH THE AVERAGE VALUE OF SAID PULSES OVER A PREDETERMINED PERIOD OF TIME; A DWELL INDICATING CIRCUIT INCLUDING INPUT CIRCUIT MEANS FOR RECEIVING A SERIES OF INPUT PULSES HAVING A VARYING CHARACTERISTIC INDICATING THE DWELL, SAID INPUT CIRCUIT MEANS HAVING SERIES IMPEDANCE MEANS, SAID METER BEING CONNECTED IN SHUNT CIRCUIT RELATIVE TO SAID SERIES IMPEDANCE MEANS FOR PRODUCING AN AVERAGE READING INDICATIVE OF THE VARIATION OF THE CHARACTERISTIC; A CURRENT MEASURING CIRCUIT INCLUDING INPUT CIRCUIT MEANS AND ADJUSTABLE IMPEDANCE MEANS IN CIRCUIT WITH SAID METER FOR VARYING THE CURRENT THROUGH SAID METER; AN IMPEDANCE MEASURING CIRCUIT FOR INDICATING THE MAGNITUDE OF AN INPUT IMPEDANCE INCLUDING A SOURCE OF ELECTRICAL ENERGY, AND IMPEDANCE MEANS IN SERIES CIRCUIT WITH THE INPUT IMPEDANCE AND IN SHUNT CIRCUIT WITH SAID METER, SAID METER SENSING THE MAGNITUDE OF CURRENT FROM SAID ELECTRICAL ENERGY SOURCE THROUGH SAID SERIES IMPEDANCE MEANS; INPUT CONDUCTOR MEANS; AND SWITCH MEANS HAVING A PLURALITY OF POSITIONS THEREON FOR SELECTIVELY ACTUATING EACH OF SAID PLURALITY OF CIRCUITS FROM SAID INPUT CONDUCTOR MEANS.