Motor with variable edge steepness

Details Motor with variable edge steepness Motor with variable edge steepness

1995-12-26

1998-03-24

Wysocki, Jonathan

Electricity: motive power systems

Limitation of motor load, current, torque or force

318254, 388934, 388815, H02P 700

Patent

active

057316740

ABSTRACT:
An improved motor for driving a variable-speed fan used, for example, to prevent overheating of electronic equipment, features an electronic controller which sends current pulses through the stator winding(s) of the motor, and varies the slope of trailing edges of these pulses in accordance with at least one sensed operating parameter of the motor, such as temperature of the power semiconductors which control the motor current. The slopes are steepened at high motor speeds to reduce electrical losses, and flattened at low motor speeds to minimize noise. Another feature of the improved motor provides for fail-safe, high-speed operation of the fan when the sensed value of the operating parameter is implausible, for example when a lead from a temperature-dependent sensing resistor breaks. In a preferred embodiment, a bridge circuit is used, which includes a transistor in one diagonal of the bridge circuit. Currently marketed personal computers use central processor chips containing several million transistors, which generate heat, and adequate, reliable cooling is absolutely essential to their proper operation. The present invention improves reliability.

REFERENCES:
patent: Re34609 (1994-05-01), Muller
patent: 4286198 (1981-08-01), De Valroger
patent: 4385265 (1983-05-01), Uzuka et al.
patent: 4415844 (1983-11-01), Mendenhall et al.
patent: 4556829 (1985-12-01), Von De Heide
patent: 4748386 (1988-05-01), Nakanishi et al.
patent: 4814674 (1989-03-01), Hrassky
patent: 5043642 (1991-08-01), Ohi
patent: 5144209 (1992-09-01), Inagi et al.
patent: 5182499 (1993-01-01), Inagi et al.
patent: 5197858 (1993-03-01), Cheng
patent: 5349275 (1994-09-01), Muller
patent: 5563480 (1996-10-01), Okada
Sanyo Electric, datasheet # 3519, "LB1860 Variable Speed Fan Motor Drivers. "
Rolf Muller, "Zweipulsige kollektorlose Gleichstrommotoren," ASR-Digest, pp. 27-31 (1977).
IBM RAMAC ad, "two cooling fans . . . to avoid overheating", INFOWORLD, vol. 17, Issue 51, Dec. 18, 1995.

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