Skip to content
PCE
Search Classifications
Search for IPC and CPC classification codes or keywords
IPC Subgroup
H02P 7/34

using Ward-Leonard arrangements

Introduced: September 1968

Last revised: January 2016

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

Classification Context

Section:
ELECTRICITY
Class:
GENERATION, CONVERSION, OR DISTRIBUTION OF ELECTRIC POWER
Subclass:
CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS

Additional Content

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

Related Keywords

WARD LEONARD sets

2 direct subcodes

Child Classifications

Navigate with arrow keys, Enter to open

  • H02P 7/343 in which both generator and motor fields are controlled
  • H02P 7/347 in which only the generator field is controlled

Top Applicants

Top 10 applicants by patent filingsfor 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