Transducer memory circuit

• US 4,611,304 A
• Filed: 07/27/1983
• Issued: 09/09/1986
• Est. Priority Date: 07/27/1983
• Status: Expired due to Fees

• Current Assignee: Alliedsignal Inc. (Honeywell International Inc.)
• Original Assignee: Sundstrand Data Control, Inc. (Rtx Corporation)
• Inventors: Bateman, Charles D., Sprague, Randall B., Butenko, R. Bruce
• Primary Examiner(s): Gruber, Felix D.
• Assistant Examiner(s): Cosimano, Edward R.
• Application Number:
  US06/517,877
• Time in Patent Office: 1,140 Days
• Field of Search: 364/481, 364/556, 364/571, 364/573, 364/900, 364/506, 364/508, 364/571, 364/566
• US Class Current: 702/58
• CPC Class Codes: G01G 19/07 for weighing aircraft
• CPC Class Codes: G01M 1/125 of aircraft
• CPC Class Codes: G01P 21/00 Testing or calibrating of apparatus or devices covered by the preceding groups

Abstract

In order to facilitate the installation of transducers such as accelerometers in a larger system, each transducer is provided with a memory circuit which is physically attached to the transducer and contains data reflecting the operating characteristics of that particular transducer. The data stored in the memory can be in the form of coefficients for polynomial equations that describe the operation of the transducer as the function of a variable such as temperature. Provision is made for transmitting this data along with the signal output from the transducer to the larger system.

Claims

1. A memory circuit for use with an accelerometer connected to a control system wherein the accelerometer is configured to transmit an output signal representing a physical quality measured by the accelerometer to the control system, said accelerometer including a proof mass supported on a pendulum by means of a hinge, the memory circuit comprising:

means for securing said memory circuit to the accelerometer;

a memory for storing data representing characteristics of the accelerometer including identity, pendulum axis alignment data, hinge axis alignment data, scale factor data and bias data, said data being stored in said memory in the form of polynominal coefficients;

access means, connected to said memory, for selectively accessing predetermined elements of said characteristic data, said access means including a control circuit connected to the control system and a counter connected to said memory and said control circuit to access said predetermined elements in said memory in response to a control signal from said control circuit;

transmission means, connected to said access means, for transmitting said predetermined elements of characteristic data to the control system, said transmission means including means for transmitting temperature data from a temperature sensor in said the accelerometer to the control system and including a multiplexer circuit for transmitting said characteristic data and said temperature data to the control system; and

indicator means, responsive to a fault signal from the control system, for producing a visible indication on the accelerometer of a fault in the accelerometer in the event that said predetermined elements fail to be transmitted to said control system in response to said access means.

2. The memory circuit of claim 1 wherein said memory includes an electronic read only memory.

3. The memory of claim 1 wherein said indicator means includes a light emitting diode.

4. In an aircraft weight and balance system having a plurality of uniquely identifiable accelerometer transducers secured to the landing gear and connected to a control computer which has been programmed to provide a self-test signal, a memory circuit for each accelerometer transducer comprising:

means for securing said memory circuit to the transducer;

an electronic memory containing data elements representing the operating characteristics of the accelerometer transducer as a function of temperature in the form of polynominal coefficients and representing the identity of the accelerometer transducer;

access means, connected to said electronic memory, for selectively accessing predetermined data elements, said access means including a counter for addressing said electronic memory, said counter being operated in response to the self-test signal from the control computer;

transmission means and a temperature sensor, connected to said access means, for transmitting said predetermined data elements and temperature data to the control computer and;

a light producing indicator responsive to a fault signal from the control computer, said fault signal being produced in the event that said control computer fails to receive said predetermined data elements in response to the self-test signal.