Data processing: structural design – modeling – simulation – and em – Simulating electronic device or electrical system – Power system
Reexamination Certificate
1998-10-14
2001-10-16
Teska, Kevin J. (Department: 2123)
Data processing: structural design, modeling, simulation, and em
Simulating electronic device or electrical system
Power system
C703S021000, C703S028000, C714S039000, C714S040000
Reexamination Certificate
active
06304839
ABSTRACT:
FIELD OF INVENTION
This invention relates to a system and method of testing printed circuit boards used in magnetic disk drives. More particularly, the present invention relates to the testing of disk drives using a system for simulating power conditions related to disk drive failures. Still more particularly, the invention relates to the testing of disk drives for resilience to power spikes, power dips, hot plugging, slow or fast ramp power conditions, power oscillation, switch induced bounce conditions, and power transients.
BACKGROUND OF THE INVENTION
Computer disk drive systems are comprised of two main components, a Head Disk Assembly (“HDA”) and the Printed Circuit Board Assembly (“PCBA”). Either or both of these components may fail during use. In order to enhance quality control and prevent disk drive failures in the field, a method of testing disk drives was needed. The present invention is concerned with testing disk drive systems for power related failures. This is accomplished using a power simulator.
In analyzing disk drive failures, it was determined that a sizable fraction of such failures resulted from anomalous power supply conditions. The present art lacks an effective tool for rapidly and effectively analyzing the effects of abnormal or extreme power supply conditions on disk drive systems. The Universal Power Simulator (“UPS”) is a testing apparatus for analyzing disk drive performance while the disk drives are subjected to a series of simulated power anomalies. This testing provides the manufacturer with accurate quality control information regarding power related disk drive failures. UPS testing of disk drive systems also insures that defective disk drives are detected and selected out before such drives are marketed. The UPS accomplishes this goal by simulating a wide range of anomalous power conditions (e.g. hot plugging, slow or fast ramp power conditions, ringing, bounce, voltage spikes, voltage dips, power transients, etc.) known to cause disk drive failures. The UPS accomplishes this task in conjunction with a host computer, a programmable power supply, a series of plug-in computer cards, and an application specific computer program.
PURPOSE OF THE INVENTION
The primary object of the present invention is to provide a system for testing disk drive system functionality over a wide range of power conditions. In keeping with this primary object, the present invention integrates a wide range of test mechanisms into an integrated system for conducting a variety of tests.
It is an object of the present invention to test the robustness of HDA's and PCBA's to rapid and excessive rises or drops in input voltage (“voltage spikes” or “voltage dips”).
Another object of the present invention to test the robustness of HDA's and PCBA's when they are connected to a “live” power supply line (also known as “hot plugging”).
Another object of the present invention to test the robustness of HDA's and PCBA's when subjected to the rapid current switching caused by the bounding action inherent in some types of switches (also called “bounce”).
Another object of the present invention to test the robustness of HDA's and PCBA's to unstable or oscillating power supply voltages (also known as “ringing”). Typically, ringing is caused by sudden changes in load or line voltages to which the disk drive's power supply responds poorly.
Another object of the present invention to test the resilience of HDA's and PCBA's to slow or fast ramp power conditions.
Another object of the present invention to test the robustness of HDA's and PCBA's to power transients. For example, those caused by power supply voltage changes due to load or line changes.
SUMMARY OF THE INVENTION
The present invention accomplishes the above-mentioned objects using a computer controlled system architecture featuring several major components.
The first of these components is a Control Host. The Control Host is a computer enhanced with features allowing the computer to communicate with disk drives having either IDE or Small Computer System Interface (“SCSI”) formats. The computer is in electrical communication with both a Programmable Power Supply (“PPS”) and the UPS. The host computer uses a combination of hardware and software to create simulated power conditions which, in conjunction with the UPS and PPS, are used test disk drives for correct operation, gleaning out defective drives.
The second major component is the PPS. The PPS is connected to, and directed by, the host computer. The function of the PPS is to supply power to the UPS according to instructions provided by the operator. The PPS is connected to both the UPS and the host computer, serving as a power source for the UPS.
The third major component is the UPS. The function of the UPS is to send test power signals to disk drives under test. The UPS receives control signals from the host computer which, in conjunction with the PPS, sends simulated power signals to the disk drives under test. The system subjects disk drives to simulated power conditions and evaluates disk drive performance and suitability for continued use. The UPS features a variety of subunits which are used to evaluate disk drive performance under specific power conditions. Examples of such subunits are a relay decoding and controlling subunit, a power switching subunit, an interface switching subunit, a power ramp subunit, and a spike generating subunit.
This integrated system of host computer, PPS, and UPS provide an efficient, compact, programmable, and interactive method of testing disk drives for resilience to anomalous power conditions.
REFERENCES:
patent: 4725968 (1988-02-01), Baldwin et al.
patent: 5357519 (1994-10-01), Martin et al.
patent: 5543727 (1996-08-01), Bushard et al.
patent: 5878053 (1999-03-01), Koh et al.
patent: 6067506 (2000-05-01), Goldys et al.
Chan Whyemun
Ho Alpha Ngai Chung
Phan Thai
Seagate Technology LLC
Teska Kevin J.
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