Abstract: A method and apparatus of inducing vibrations and buzzes within a vehicle, e.g., from panel trim, provides a reliable and repeatable way to identify the sources of such vibrations and buzzes. According to the method, an FM transmitter modulates and transmits predetermined frequency signals to a standard FM receiver located in the interior of the car. The FM receiver receives and demodulates the signal, and then applies it to audio speakers also located within the vehicle. The output signal from the speakers induces sympathetic vibrations in vehicle components, allowing a tester to identify the sources of the vibrations and buzzes so that they may be corrected. The transmitter provides a means for a user to maintain a constant frequency or to vary the frequency within a predetermined range of frequencies. The frequency may be generated by digitally storing one complete sine wave in successive memory locations. The values can then be retrieved and converted to an analog signal.

Abstract: A variable transient simulator employs a source of pulsating DC voltage for charging a first capacitance bank to a desired potential difference. After a device under test (DUT) is connected to a second capacitance bank, the charged-up first capacitance band is isolated from the DC voltage source and allowed to discharge into the second capacitance bank and, together, both capacitance banks provide discharging current into the DUT which simulates a desired loop during transient response. The simulator can provide repetitive as well as variable positive and negative transients.

Abstract: A serial data direct memory access system including a control circuit that shares control with a master computer of an interface bus of a DMA storage system. Serial data is supply to the control circuit via a fiber optic cable. The control circuit employs means responsive to status code bits of the message words for gaining control from the master computer of the interface bus and for directly accessing the computer controlled bus memory storage system. This system is capable of handling data streams of infinite lengths. Also, means are provided for preventing bit errors from interfering with critical message words.

Abstract: An optics fiber multiplexed data acquisition system includes an analog modular for collecting data and then transmitting the data by fiber optics cable to a memory module located at a remote location. The memory module employs means for directly accessing a computer controlled bus memory storage system.