2250770

Information

• Patent Grant
• 2250770

• References
• Source

• Patent Number

  2,250,770

• Date Filed

  Not available

• Date Issued

  Tuesday, July 29, 1941
  84 years ago

• CPC

  • H04Q5/06 - Signalling by amplitude or polarity of dc

• US Classifications

  • 379 - Telephonic communications