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DIFF Subgroup
H02P 7/34

using Ward-Leonard arrangements

Introduced: September 1968

Full Title

Arrangements for regulating or controlling the speed or torque of electric DC motors > for regulating or controlling an individual DC dynamo-electric motor by varying field or armature current > by master control with auxiliary power > using Ward-Leonard arrangements

Additional Content IPC

Ward-Leonard system The term 'Ward-Leonard system' refers to a method of controlling the speed and direction of rotation of a DC motor by varying and if necessary reversing its armature voltage. A DC generator provides the variable armature supply. The output of the generator is controlled by control of its field current. Armature a rotor which carries a winding connected to a commutator

IPC and CPC are identically structured here. All 2 subcodes exist in both systems.

IPC defines codes here since 2016.

Child Classifications

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  • H02P 7/343 in which both generator and motor fields are controlled since 2016 IPC+CPC Available in IPC and CPC
  • H02P 7/347 in which only the generator field is controlled since 2016 IPC+CPC Available in IPC and CPC

Top Applicants

Top Applicants (IPC)

Class H02,2013–2023, worldwide · Source: EPO PATSTAT

  1. SGCC(STATE GRID CORPORATION OF CHINA) 54,496
  2. MITSUBISHI ELECTRIC CORPORATION JP 10,495
  3. TOYOTA MOTOR CORPORATION 9,464
  4. GUANGDONG POWER GRID CORPORATION 9,339
  5. ROBERT BOSCH DE 8,226
  6. SIEMENS DE 8,218
  7. DENSO CORPORATION 7,063
  8. MITSUBISHI ELECTRIC CORPORATION 6,619
  9. SAMSUNG ELECTRONICS COMPANY KR 5,826
  10. GREE ELECTRIC APPLIANCES 5,094

Top Applicants (CPC)

Class H02,2013–2023, worldwide · Source: EPO PATSTAT

  1. SGCC(STATE GRID CORPORATION OF CHINA) 24,515
  2. MITSUBISHI ELECTRIC CORPORATION JP 11,346
  3. SIEMENS DE 9,026
  4. ROBERT BOSCH DE 9,005
  5. SAMSUNG ELECTRONICS COMPANY KR 6,729
  6. GUANGDONG POWER GRID CORPORATION 5,740
  7. DENSO CORPORATION JP 5,077
  8. LG ELECTRONICS KR 5,041
  9. LG INNOTEK COMPANY KR 4,442
  10. TOYOTA MOTOR CORPORATION 4,349