2492240

Information

• Patent Grant
• 2492240

• References
• Source

• Patent Number

  2,492,240

• Date Filed

  Not available

• Date Issued

  Tuesday, December 27, 1949
  74 years ago

• CPC

  • H04Q9/06 - Calling by using amplitude or polarity of dc

• US Classifications

  • 318 - Electricity: motive power systems
  • 361 - Electricity: electrical systems and devices