TWO CONDUCTOR TELEMETERING SYSTEM

• US 3,717,858 A
• Filed: 08/12/1970
• Issued: 02/20/1973
• Est. Priority Date: 08/12/1970
• Status: Expired due to Term

• Current Assignee: Detector Electronics Corporation (Carrier Global Corporation)
• Original Assignee: David M. Hadden
• Inventors: Hadden, David M.
• Primary Examiner(s): Caldwell, John W.
• Assistant Examiner(s): Mooney, Robert J.
• Application Number:
  US05/063,155
• Time in Patent Office: 923 Days
• Field of Search: 340/203,206,237,210 323/22T,DIG.1 321/2,45S
• US Class Current: 340/870.2
• CPC Class Codes: G08C 19/26 by varying pulse repetition frequency
• CPC Class Codes: Y10S 323/901 Starting circuits

Abstract

In a two conductor telemetering system, a sensor and transmitter are disposed at an outlying station. The transmitter produces a train of pulses having a repetition rate which is a function of the quantity being measured by the sensor. The pulses are transmitted over a two conductor transmission line to a base station counter to the flow of power from the base station to energize the sensor and transmitter. A switching voltage regulator is provided at the outlying station for converting the supplied dc power of a relatively high unregulated voltage and low current to a regulated relatively low voltage at high current for energizing the sensor and transmitter.

Claims

1. In a telemetering apparatus, sensor means for disposition at an outlying station and for sensing a parameter to be measured and for producing a sensor output which is a function of the parameter being measured, pulse generator means for location proximate the outlying station and for converting the sensor output into an output train of pulses which have a parameter wHich is a function of the sensor output signal, a pair of conductors for interconnecting the outlying station with a base station and for providing a transmission line for flow of power from the base station to said sensor and pulse generator means and for flowing the output train of pulses of said pulse generator means from the outlying station in a direction counter to the direction of power flow to the outlying station, receiver means for connection to said transmission line proximate the base station for receiving the output train of pulses and for producing an output which is a function of the parameter being sensed, voltage regulator means to be located at the outlying station and to be connected to said pair of conductors to receive power flowing from a power supply at the base station over said transmission line formed by said pair of conductors for producing output power to be supplied for energizing said sensor, such output power being of a substantially reduced and regulated voltage relative to the input voltage to said regulator means, and control means having first and second stable reference control outputs for controlling said voltage regulator means such that the regulated output voltage of said regulator means is maintained at a first output level corresponding to said first control output when the input voltage to said regulator means is below a first input level and maintained at a second output level corresponding to said second control output and higher than the first output level when the input voltage to said regulator means is above the first input level.

2. In a telemetering apparatus, sensor means for disposition at an outlying station and for sensing a parameter to be measured and for producing a sensor output which is a function of the parameter being measured, pulse generator means for location proximate the outlying station and for converting the sensor output into an output train of pulses which have a parameter which is a function of the sensor output signal, a pair of conductors for interconnecting the outlying station with a base station and for providing a transmission line for flow of power from the base station to said sensor and pulse generator means and for flowing the output train of pulses of said pulse generator means from the outlying station to the base station in a direction counter to the direction of power flow to the outlying station, receiver means for connection to said transmission line proximate the base station for receiving the output train of pulses and for producing an output which is a function of the parameter being sensed, voltage regulator means to be located at the outlying station and to be connected to said pair of conductors to receive power flowing from a power supply at the base station over said transmission line formed by said pair of conductors for producing output power being of a substantially reduced and regulated voltage relative to the input voltage to said regulator means, said voltage regulator means being a switching regulator, whereby power of a regulated voltage is supplied efficiently to said sensor means;

and wherein said sensor means includes, catalytic combustible gas detection filament means to be directly heated by current passed through said filament means from the output of said regulator means.

3. The apparatus of claim 2 wherein said filament means includes a pair of catalytic combustible gas detection filaments, electrical bridge means having each of said filaments in different respective arms of said bridge and connected to said voltage regulator means to be energized by the output of said regulator means, and wherein the output of said bridge constitutes the output signal of said sensor.

4. In a telemetering apparatus, sensor means for disposition at an outlying station and for sensing a parameter to be measured and for producing a sensor output which is a function of the parameter being measured, pulse generator means for location proximate the outlying station and for conveRting the sensor output into an output train of pulses which have a parameter which is a function of the sensor output signal, a pair of conductors for interconnecting the outlying station with a base station and for providing a transmission line for flow of power from the base station to said sensor and pulse generator means and for flowing the output train of pulses of said pulse generator means from the outlying station to the base station in a direction counter to the direction of power flow to the outlying station, receiver means for connection to said transmission line proximate the base station for receiving the output train of pulses and for producing an output which is a function of the parameter being sensed, and failure sensor means connected to at least one of said pair of conductors proximate the base station end thereof for sensing a reduction in the current flow over said pair of conductors from the power source to the outlying station and for producing an output indicative of such current flow reduction, such reduction in current flow being indicative of the failure of a power consuming device at the outlying station.

5. The apparatus of claim 4 including, alarm means connected to receive the output of said receiver means and for producing an alarm output when the output of said receiver means is indicative of a predetermined combustible level sensed by said sensor means, and inhibit means connected to receive the output of said failure sensor and being responsive to a failure output of said failure sensor for inhibiting the alarm output of said alarm means in response to a failure output signal.