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Class Information
Number: 318/71
Name: Electricity: motive power systems > Plural, diverse or diversely controlled electric motors > Running-speed control > Relative motor speed control > With speed-difference detector > Electrical-type detectors > Voltage and/or current difference detector
Description: Subject matter in which each of two or more of the motors is provided with means for generating electrical voltages and/or currents or is provided with means for controlling a separate voltage or current, the detecting or sensing means being operated by the difference in magnitude between the two separately generated or controlled voltages or currents.

Patents under this class:

Patent Number Title Of Patent Date Issued
8508182 Electrically connecting blower to power supply stage providing higher voltage Aug. 13, 2013
8133033 High voltage bus capacitor pre-charger circuit Mar. 13, 2012
7190146 Control system and method for an overhead bridge crane Mar. 13, 2007
7090470 Apparatus and method for preventing a piston and valve collision in a linear compressor Aug. 15, 2006
6972532 Controlled motor coast in media handling system Dec. 6, 2005
6737828 Washing machine motor drive device May. 18, 2004
6600278 Clean power common buss variable frequency drive system Jul. 29, 2003
6532405 Method for detecting a locked axle on a locomotive AC traction motor Mar. 11, 2003
6133700 Torque controller system having a torque processor with improved tractive effort distribution Oct. 17, 2000
6081080 Method and apparatus for reducing voltage stresses in electric machines Jun. 27, 2000
6037724 Electronic controlled surgical power tool Mar. 14, 2000
6028402 Automatic rail characterization for adhesion system evaluation for AC locomotives Feb. 22, 2000
5898281 Method and device for the common regulation of several electric motors driving the driving wheels of a motor vehicle Apr. 27, 1999
5841254 Torque maximization and vibration control for AC locomotives Nov. 24, 1998
5712543 Magnetic switching element for controlling a surgical device Jan. 27, 1998
5625262 System for equalizing the load of a plurality of motors Apr. 29, 1997
5610819 System for enhancing wheel traction in a locomotive by reapplication of excitation using an S-shaped curve Mar. 11, 1997
5408164 Differential speed control of electric motors Apr. 18, 1995
5313149 Current supply control apparatus for inductance load May. 17, 1994
5117163 Drive system for railway vehicle May. 26, 1992
5077506 Microprocessor controlled arthroscopic surgical system Dec. 31, 1991
4896090 Locomotive wheelslip control system Jan. 23, 1990
4888533 Brushless DC motor Dec. 19, 1989
4825131 Control system for induction motor driven electric car Apr. 25, 1989
4780650 Control system for a power converter for driving induction motors Oct. 25, 1988
4757240 Apparatus for controlling electric vehicle using induction motor Jul. 12, 1988
4686434 Electric vehicle monitoring system Aug. 11, 1987
4647824 Output voltage control for a DC servo amplifier Mar. 3, 1987
4641069 Plural motor changeover control system Feb. 3, 1987
4463289 Wheel slip control using differential signal Jul. 31, 1984
4454455 Fault responsive means for changing control sequence of a multiple-bridge electric power converter Jun. 12, 1984
4420713 Turn-off control means for an ac-to-dc electric power converter Dec. 13, 1983
4392091 Vehicle propulsion control apparatus and method Jul. 5, 1983
4387325 Electric wheelchair with speed control circuit Jun. 7, 1983
4335337 Control system for electric motor vehicle Jun. 15, 1982
4292572 Method and apparatus for regulating electric motor armature currents Sep. 29, 1981
4122377 Variable speed, alternating current motor unit and methods and apparatus for speed control of same Oct. 24, 1978
4012674 Dual motor web material transport system Mar. 15, 1977
3997822 Method of controlling locomotive wheel slip Dec. 14, 1976

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