TEMPERATURE MEASUREMENT HAVING SENSOR AND REFERENCE DIODES AT INPUTS OF REGENERATIVE DIFFERENTIAL AMPLIFIER

• US 3,604,957 A
• Filed: 05/02/1969
• Issued: 09/14/1971
• Est. Priority Date: 05/02/1969
• Status: Expired due to Term

• Current Assignee: Otto G. Satula
• Original Assignee: Otto G. Satula
• Inventors: Satula, Otto G.
• Primary Examiner(s): Forrer, Donald D.
• Assistant Examiner(s): Dixon, Harold A.
• Application Number:
  US04/821,351
• Time in Patent Office: 865 Days
• Field of Search: 307/310,229 330/104,3D,1A 324/106 328/3
• US Class Current: 327/512
• CPC Class Codes: G01K 7/01 using semiconducting elements having PN junctions G01K7/02, G01K7/16, G01K7/30 take precedence
• CPC Class Codes: H03F 3/343 with semiconductor devices only

Abstract

A differential-temperature-sensing system including a temperature-sensing network having a linear voltage drop characteristic to provide a differential voltage input signal to an amplifier which is balanced to provide a set output voltage when the differential input voltage is zero and a monitoring network having a feedback circuit connected to the amplifier input to trigger the amplifier in response to a change in the set output voltage.

Claims

1. A differential-temperature-detecting system comprising a differential amplifier including means for balancing said amplifier to provide a predetermined output voltage and having a pair of inputs, a temperature reference probe and a remote temperature-sensing probe, said probes comprising semiconductor junctions having poles disposed in opposite directions with respect to respective inputs of said differential amplifier, said probes being connected to said amplifier inputs for providing a voltage signal in response to a change in temperature between the temperature at the reference probe and the temperature at the remote probe, a positive feedback circuit connected to trigger said amplifier to a stable high output condition in response to a small change in the set output voltage, and means to detect the change in output voltage from the predetermined output voltage of said amplifier.

2. A temperature-sensing system according to claim 1 wherein said detecting means includes a voltage divider circuit and a diode connected between the amplifier and the voltage divide.

3. A temperature-sensing system according to claim 2 wherein said feedback circuit is connected to said voltage divide.

4. A temperature-sensing system according to claim 1 wherein each of the reference probe and the remote probe include a pair of diodes arranged to conduct current in the same direction, said diodes having linear forward voltage drop characteristics, said reference probe and said remote probe being matched in said voltage drop characteristics.

5. A temperature-sensing system according to claim 1 further comprising means to apply a voltage pulse to said amplifier to return the output voltage to said predetermined value.