Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Noncontact temperature measuring device










Image Number 2 for United States Patent #4456390.

A portable, battery operated noncontact temperature measuring device including a lens for collecting infrared radiation and a thermopile for producing a signal indicative of the intensity thereof. The thermopile signal is amplified, linearized and summed with an ambient temperature signal derived from a temperature responsive element, e.g. a diode chip mounted immediately adjacent a cold junction of the thermopile. The resulting composite temperature signal is then processed and displayed. The ambient temperature signal is also utilized to control the impedance of a dual field effect transistor, which in turn controls the gain of the amplifier. Thus, temperature induced variations in the responsivity of the thermopile are compensated by corresponding changes in the gain of the amplifier. An adjustable high impedance bias circuit provides bias current to the input of the amplifier, insuring that the signal at the output of the amplifier will not be affected by temperature induced changes in the internal resistance of the thermopile. A switching circuit alternately connects the output of the thermopile and a resistor having a resistance approximately equal to the internal resistance of the thermopile to the input of the amplifier. When the resistor is so connected, an automatic zeroing circuit reduces the amplifier output to approximately zero, thereby essentially eliminating amplifier drift.








 
 
  Recently Added Patents
Systems and methods for dissipating an electric charge while insulating a structure
Process for preparing synthetic intermediates of peripherally-selective inhibitors of dopamine-.beta.-hydroxylase involving catalytic asymmetric hydrogenation
Semiconductor device and manufacturing method thereof
Method for reserving network bandwidth for versioned network services
Porous polymeric resins
Fast port switching in an audiovisual receiver by use of port pre-authentication by a partial PHY decoder core
Network traffic demotion
  Randomly Featured Patents
Compositions comprising fluoroolefins and uses thereof
Object recognition in images
Segmented engine flow control device
System and method for collection, distribution, and use of information in connection with commercial real estate
Electric dipole streamer discharge type lightning conductor
Planing machine
Retro-fit receptacle mounting method and apparatus
Methods and systems for generating electronic program guides
Grill
Wagering game machine with a type driven interface