Robert Boschgmbh

Rudolf Blum

Walter Dinkelacker

Jurgen Knodler

Klaus Abele

Peter Ebinger

To provide for accurate testing of the performance of automotive vehicles on test stands in which the wheels of the vehicle are in engagement with inertia rollers, the inertia rollers being accelerated through the vehicle wheels by the vehicle engine, and the torque measured, and then decelerated by disconnecting of engine driving power and coasting torque measured, operating parameters related to speed and rate of change of speed are sensed and a speed signal is provided, tractive effort is sensed and a traction signal provided, and the signals are combined to provide an output representative of engine performance, the combined signals being further modified by the output of a correction stage which introduces correction signals such as pressure, ambient temperature, presence or absence of automatic transmission, or the like; the apparatus further comprises selectable switches, for example a speed selector switch, so that measurements can be taken with respect to predetermined design speeds to test performance of the vehicle, or an engine, with respect to such a predetermined speed.

Automotive vehicle performance test stand system and performance

To prevent transfer of stray pulses from the ignition system to test apparatus, a pulse-shaping circuit is connected between the output of the ignition system and the test apparatus itself which includes a semiconductor switch providing an output signal to the test apparatus upon change of state thereof, and a charge storage circuit connected to the coupling element of the test system to the ignition system and to the semiconductor switch, the charge storage circuit having a short loading time and a re-loading or discharge time which is long with respect to the loading time thereof to rapidly transfer pulses to the switch and cause rapid change of state thereof while slowly unloading the charge and prevent further change of state of the switch during the unloading time, and thus suppress and eliminate stray pulses.

Automotive test apparatus for coupling to the ignition system of

To provide output power, for example for automotive test equipment from input sources having widely varying input voltages, for example between 4.5 and 32 V, without range switches, or setting potentiometers, a blocking oscillator circuit including a transformer and a switching transistor in series with the primary are connected across the input terminals, one secondary of the transformer charging a capacitor, another secondary of the transformer charging an auxiliary capacitor, the output voltage of which is connected to a control transistor to interrupt operation of the blocking oscillator formed by the transformer primary and the transistor when the voltage applied to the control transistor control electrode exceeds a reference value established, for example, by a Zener diode; a sensing resistor is connected in series with the main switching transistor, across which an output voltage is taken which is in turn applied to the control electrode of the control transistor to interrupt blocking oscillator operation of the main transistor when the current through the sensing resistor exceeds a predetermined value.

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Wendlingen, Germany

Rudolf Blum