3883868

Information

• Patent Grant
• 3883868

• References
• Source

• Patent Number

  3,883,868

• Date Filed

  Not available

• Date Issued

  Tuesday, May 13, 1975
  49 years ago

• CPC

  • G08B26/002 - only replying the state of the sensor
  • H04N7/173 - with two-way working
  • H04Q9/08 - Calling by using continuous ac
  • H04N2007/17372 - the upstream transmission being initiated or timed by a signal from upstream of the user terminal
  • Y10T307/773 - Light, heat, vibratory or radiant energy

• US Classifications

  • 307 - Electrical transmission or interconnection systems
  • 348 - Television