1520974

Information

• Patent Grant
• 1520974

• References
• Source

• Patent Number

  1,520,974

• Date Filed

  Not available

• Date Issued

  Tuesday, December 30, 1924
  100 years ago

• CPC

  • H02P5/50 - by comparing electrical values representing the speeds
  • Y10S200/32 - Speed responsive
  • Y10T307/872 - Repetitive make and break

• US Classifications

  • 388 - Electricity: motor control systems
  • 200 - Electricity: circuit makers and breakers
  • 307 - Electrical transmission or interconnection systems
  • 318 - Electricity: motive power systems