2218502

Information

• Patent Grant
• 2218502

• References
• Source

• Patent Number

  2,218,502

• Date Filed

  Not available

• Date Issued

  Tuesday, October 22, 1940
  84 years ago

• CPC

  • G05D23/2239 - using photoelectric elements

• US Classifications

  • 236 - Automatic temperature and humidity regulation
  • 219 - Electric heating
  • 250 - Radiant energy
  • 324 - Electricity: measuring and testing
  • 330 - Amplifiers
  • 340 - Communications: electrical
  • 361 - Electricity: electrical systems and devices