3842208

Information

• Patent Grant
• 3842208

• References
• Source

• Patent Number

  3,842,208

• Date Filed

  Not available

• Date Issued

  Tuesday, October 15, 1974
  50 years ago

• CPC

  • H04M11/04 - with fire, police, burglar, or other alarm systems
  • H04M1/573 - Line monitoring circuits for detecting caller identification
  • H04Q1/32 - using trains of dc pulses

• US Classifications

  • 379 - Telephonic communications