Temperature detector using a surface acoustic wave device

• US 4,249,418 A
• Filed: 04/12/1979
• Issued: 02/10/1981
• Est. Priority Date: 04/20/1978
• Status: Expired due to Term

• Current Assignee: Tokyo Shibaura Denki Kabushiki Kaisha (Toshiba Corporation)
• Original Assignee: Tokyo Shibaura Denki Kabushiki Kaisha (Toshiba Corporation)
• Inventors: Ebata, Yasuo
• Primary Examiner(s): Ruehl, Charles A.
• Application Number:
  US06/029,530
• Time in Patent Office: 670 Days
• Field of Search: 73/339 A, 73/DIG. 4, 73/597, 331/107 A, 331/155, 310/313
• US Class Current: 374/117
• CPC Class Codes: G01K 1/024 for remote indication
• CPC Class Codes: G01K 11/22 using measurement of acoustic effects
• CPC Class Codes: G01K 11/26 of resonant frequencies
• CPC Class Codes: G01K 11/265 using surface acoustic wave [SAW]

Abstract

A transmitting section includes an oscillator which has a surface acoustic wave device of which the frequency characteristic varies responding to the temperature of a base plate thereof, the oscillator generating an oscillation output of a frequency corresponding to the frequency characteristic and an antenna for transmitting the oscillation output. A receiving section includes a receiving antenna, a means for detecting the output of the receiving antenna, and a signal processing circuit for processing the output of the detecting means to generate at least one of the temperature display and control signals of the base plate of the surface acoustic wave device.

Claims

1. A temperature detector using a surface acoustic wave device comprising:

a transmitting section including an oscillator having a surface acoustic wave device of which the frequency characteristic varies responding to the temperature of a base plate thereof, said base plate being attached to a member having good heat conductivity through a flexible adhesive layer, said oscillator generating an oscillating output of a frequency corresponding to said frequency characteristic of said surface acoustic wave device, and a first antenna coupled to said oscillator for transmitting said oscillating output; and

a receiving section including a second antenna for receiving the output of said first antenna, a means for detecting the oscillation frequency of said oscillator from the output of said second antenna, and a signal processing circuit for processing the output of said detecting means.

2. A temperature detector using a surface acoustic wave device according to claim 1 wherein said surface acoustic wave device is a surface acoustic wave resonator.

3. A temperature detector using a surface acoustic wave device according to claim 1 wherein said surface acoustic wave device is a surface acoustic wave delay line.

4. A temperature detector using a surface acoustic wave device according to claim 1 wherein said base plate of the surface acoustic wave device is a Y-cut and Z-propagation base plate of lithium niobate.

5. A temperature detector using a surface acoustic wave device according to claim 1 wherein said oscillator is provided with a means which causes said oscillator to be oscillated intermittently.

6. A temperature detector using a surface acoustic wave device according to claim 1 wherein said means for detecting the oscillation frequencies of the oscillator includes a reference frequency oscillator, a mixer for picking up the output of a difference frequency between the output frequency of the second antenna and the reference frequency, and a counter for counting the output frequency of said mixer;

and wherein said signal processing circuit is a micro-computer which receives, as an input, the output of said counter and emits an output.