3828139

Information

• Patent Grant
• 3828139

• References
• Source

• Patent Number

  3,828,139

• Date Filed

  Not available

• Date Issued

  Tuesday, August 6, 1974
  50 years ago

• CPC

  • H04M19/006 - Circuits for increasing the range of current supply source
  • H04M3/30 - for subscriber's lines , for the local loop

• US Classifications

  • 379 - Telephonic communications