1439639

Information

• Patent Grant
• 1439639

• References
• Source

• Patent Number

  1,439,639

• Date Filed

  Not available

• Date Issued

  Tuesday, December 19, 1922
  102 years ago

• CPC

  • H02P9/20 - due to variation of continuously-variable ohmic resistance

• US Classifications

  • 323 - Electricity: power supply or regulation systems
  • 322 - Electricity: single generator systems
  • 338 - Electrical resistors