Patent · US Expired

Electronic thermostat

US4206872A · kind A · utility

192Cited by
8References
17Claims
0Family size

Inventor

Key dates

Filing dateMar 17, 1977
Grant dateJun 10, 1980
Priority date
Expiry dateMar 17, 1997

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG05D23/1904
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

A thermostat for generating control signals for a furnace, air conditioner, or the like, employs a constant frequency, periodically alternating electrical source and an oscillator incorporating an element having a thermal-sensitive electrical characteristic so the oscillator frequency varies as a function of the ambient temperature. A comparator receives the two outputs and generates a signal representative of the ambient temperature. The stable output is also provided to dividing circuits to generate a signal representative of the time that is used to interrogate a digital memory storing a desired temperature-time program for the thermostat for a repetitive period, such as a week or month. The ambient temperature signal is compared with the desired temperature signal to generate an output control signal. A display provides a read-out of time and temperature and is used along with a keyboard or the like in programming the memory.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.