US4888996A — DC motor operated valve remote monitoring system

Claim 1

Independent Claim 224 words

Apparatus for monitoring the torque delivered by a DC electric motor which motor includes at :east an armature shaft, and an armature within an armature circuit, said apparatus comprising: voltage detecting means for detecting the voltage drop (Va) across the armature circuit; current detecting means for detecting the current (Ia) supplied to the armature; resistance detecting means for detecting armature circuit electrical resistance (Ra); first analog circuit means for representing, at least, the function Ia(Va - IaRa) and for providing a representative output; means for providing detected Ia, V4 and Ra as input to said first analog circuit means; second analog circuit means for representing, at least, the function ##EQU4## where Sr is the name plate rated speed of the motor, Vris the name plate rated voltage of the motor and Ir is the name plate rated current of the motor and for providing a representative output; means for providing detected Va, Ia and Ra as input to said second analog circuit means; and third analog circuit means for dividing said output from said first analog circuit means by said output from said second analog circuit means, and for providing a representative output; whereby the resultant output of said third analog circuit means is a torque factor representative of the mechanical output torque delivered by the DC motor armature shaft multiplied by a constant.

Claim 2

Dependent Claim 224 words

Apparatus for monitoring the torque delivered by a DC electric motor which motor includes at :east an armature shaft, and an armature within an armature circuit, said apparatus comprising: voltage detecting means for detecting the voltage drop (Va) across the armature circuit; current detecting means for detecting the current (Ia) supplied to the armature; resistance detecting means for detecting armature circuit electrical resistance (Ra); first analog circuit means for representing, at least, the function Ia(Va - IaRa) and for providing a representative output; means for providing detected Ia, V4 and Ra as input to said first analog circuit means; second analog circuit means for representing, at least, the function ##EQU4## where Sr is the name plate rated speed of the motor, Vris the name plate rated voltage of the motor and Ir is the name plate rated current of the motor and for providing a representative output; means for providing detected Va, Ia and Ra as input to said second analog circuit means; and third analog circuit means for dividing said output from said first analog circuit means by said output from said second analog circuit means, and for providing a representative output; whereby the resultant output of said third analog circuit means is a torque factor representative of the mechanical output torque delivered by the DC motor armature shaft multiplied by a constant.

Claim 3

Dependent Claim 29 words

Apparatus of claim 1, wherein said resistance detecting means comprises at least means for isolating the armature circuit resistance and means for representing said isolated resistance as a voltage.

Claim 4

Dependent Claim 153 words

Apparatus of claim 1, wherein said resistance detecting means comprises at least: a voltage source; variable resistance means for selectively creating various resistances within a circuit; a tuning circuit including therein, at least, said voltage source, said variable resistance means, and connecting means for connection to the armature circuit resistance, wherein said variable resistance means is varied to isolate a matching resistance which matches the armature circuit resistance; a resistance representing voltage supply circuit including, at least, voltage output terminals, said variable resistance means, and aid voltage source wherein the voltage drop across said voltage output terminals equals the voltage drop across said matching resistance of said variable resistance means, and switching means for selectively placing said variable resistance means first in said tuning circuit and then in said voltage supply circuit; whereby said armature circuit electrical resistance is isolated and then represented as a voltage for input to said analog circuit means.

Claim 5

Dependent Claim 12 words

Apparatus of claim 3, wherein said tuning circuit comprises a Wheatstone bridge.

Claim 6

Dependent Claim 48 words

Apparatus of claim 3, wherein said resistance detecting means further comprises, at least, first scaling means for assuring a representative voltage output at said voltage output terminals of said voltage supply circuit is in the ratio of 1 ohm of armature circuit resistance equals one millivolt voltage output.

Claim 7

Dependent Claim 31 words

Apparatus of claim 3, wherein said current detecting means includes, at least, means for representing said current supplied to the armature as a voltage for input to said analog circuit means.

Claim 8

Dependent Claim 34 words

Apparatus of claim 6, wherein said first analog circuit means further comprises, at least, brush loss circuit means for representing the function [-2Ia], wherein said first analog circuit means represents the composite function: Ia(Va-IaRa)-2Ia.

Claim 9

Dependent Claim 34 words

Apparatus of claim 3, wherein said first analog circuit means further comprises, at least, brush -loss circuit means for representing the function [-2Ia], wherein said first analog circuit means represents the composite function: Ia(Va-IaRa)-2Ia.

Claim 10

Dependent Claim 38 words

Apparatus of claim 1, wherein said second analog circuit means further comprises, at least, brush drop circuit means for subtracting a value of 4 volts from Va, wherein said second analog circuit means represents the composite function: ##EQU5##

Claim 11

Dependent Claim 17 words

Apparatus of claim 1, further comprising means for recording said output of said third analog circuit means.

Claim 12

Dependent Claim 44 words

Apparatus of claim 1, wherein said output (Vout) of said third analog circuit means defines a value of a Torque factor (T f ) representative of the mechanical output torque (T) generated by the DC motor armature shaft in the relationship Vout=T f =Tk.

Claim 13

Dependent Claim 6 words

Apparatus of claim 11, wherein k=1/7.04.

Claim 14

Dependent Claim 32 words

Apparatus of claim 1, wherein said current detecting means includes, at least, means for representing said input current supplied to the motor as a voltage for input to said analog circuit means.

Claim 15

Dependent Claim 28 words

Apparatus of claim 1, wherein said value of Va is reduced within said second analog circuit means by a value representative of the voltage drop across the brushes.

Claim 16

Dependent Claim 35 words

Apparatus of claim 14, wherein said first analog circuit means further comprises, at least, brush loss circuit means for representing the function [-2Ia], wherein said first analog circuit means represents the composite function: Ia(Va-IaRa) -2Ia.

Claim 17

Dependent Claim 132 words

Apparatus for monitoring the torque delivered by a DC electric motor which motor includes at least an armature shaft and an armature within an armature circuit, of said apparatus comprising: power analog circuit means for representing at least a portion of mechanical output power of the armature by analog circuitry, and for providing a representative power output; speed analog circuit means for representing at least a portion of rotational speed of the armature by analog circuitry, and for providing a representative speed output; and third analog circuit means for combining said power output and said speed output to generate a torque factor, whereby the DC motor torque is monitored by monitoring the torque factor which is representative of the mechanical output torque delivered by the DC motor armature multiplied by a constant.

Claim 18

Dependent Claim 132 words

Apparatus for monitoring the torque delivered by a DC electric motor which motor includes at least an armature shaft and an armature within an armature circuit, of said apparatus comprising: power analog circuit means for representing at least a portion of mechanical output power of the armature by analog circuitry, and for providing a representative power output; speed analog circuit means for representing at least a portion of rotational speed of the armature by analog circuitry, and for providing a representative speed output; and third analog circuit means for combining said power output and said speed output to generate a torque factor, whereby the DC motor torque is monitored by monitoring the torque factor which is representative of the mechanical output torque delivered by the DC motor armature multiplied by a constant.

Claim 19

Dependent Claim 97 words

Apparatus of claim 16, wherein said power analog circuit means comprises, at least, circuit means for representing the function Ia(Va -IaRa) wherein Ia, Va and Ra are voltages representing, respectively, current supplied to the armature, voltage drop across the armature circuit and armature circuit electrical resistance; and wherein said speed analog circuit means comprises, at least, circuit means for representing the function ##EQU6## wherein Sr, Vr and Ir are voltages representing, respectively, the name plate rated speed of the motor, the name plated rated voltage of the motor and the name plate rated current of the motor.

Claim 20

Dependent Claim 35 words

Apparatus of claim 17, wherein said power analog circuit means further comprises, at least, brush loss circuit means for representing the function [-2Ia], wherein said power analog circuit means represents the composite function: Ia(Va-IaRa) -2Ia.

Claim 21

Dependent Claim 28 words

Apparatus of claim 18, wherein said value of Va is reduced within said second analog circuit means by a value representative of the voltage drop across the brushes.

Claim 22

Dependent Claim 38 words

Apparatus of claim 19, wherein said speed analog circuit means further comprises, at least, brush drop circuit means for subtracting a value of 4 volts from Va, wherein said speed analog circuit means represents the composite function: ##EQU7##

Claim 23

Dependent Claim 39 words

Apparatus of claim 17, wherein said speed analog circuit means further comprises, at least, brush drop circuit means for subtracting a value of 4 volts from Va, wherein said speed analog circuit means represents the composite function of ##EQU8##

Claim 24

Dependent Claim 55 words

Apparatus of claim 17, further comprising: Va detecting means for detecting Va; means for detecting said current supplied to the armature as a current and for representing said current as said Ia voltage; means for detecting and isolating said armature circuit electrical resistance as a resistance and for representing said resistance as said Ra voltage.

Claim 25

Dependent Claim 92 words

Apparatus of claim 22, further comprising: Va scaling means for scaling said Va voltage to a scaled value for input to said power and speed analog circuits; Ia scaling means for scaling said la voltage to a scaled value for input to said power and speed analog circuits; Ra scaling means for scaling aid Ra voltage to a scaled value for input to said power and speed analog circuits; and means for providing said scaled values of Va, Ia and Ra to said power analog circuit and to said speed analog circuit.

Claim 26

Dependent Claim 172 words

Apparatus of claim 22, wherein said means for detecting and isolating said armature circuit electrical resistance as a resistance and for representing said resistance as said Ra voltage comprises, at least: a voltage source; variable resistance means for selectively creating various resistances within a circuit; a tuning circuit including therein, at least, said voltage source, said variable resistance means, and connection means for connection to the armature circuit resistance, wherein said variable resistance means is varied to isolate a matching resistance which matches the armature circuit resistance; a resistance representing voltage supply circuit including, at least, voltage output terminals, said variable resistance means, and said voltage source, wherein the voltage drop across said voltage output terminals equals the voltage drop across said matching resistance of said variable resistance means, and switching means for selectively placing said variable resistance means first in said tuning circuit and then in said voltage supply circuit, whereby said armature circuit electrical resistance is isolated and then represented as a voltage for input to said analog circuit means.

Claim 27

Dependent Claim 12 words

Apparatus of claim 24, wherein said tuning circuit comprises a Wheatstone bridge.

Claim 28

Dependent Claim 68 words

Apparatus of claim 24, wherein said means for detecting and isolating said armature circuit electrical resistance as a resistance and for representing said resistance as said Ra voltage further comprises, at least, first scaling means for assuring a representative voltage output at said voltage output terminals of said voltage supply circuit is in the ratio of 1 ohm of armature circuit resistance equals one millivolt of voltage output.

Claim 29

Dependent Claim 133 words

Method of monitoring the torque delivered by a DC electric motor which motor includes at least an armature shaft and an armature within an armature circuit, said method comprising the steps of: monitoring current (Ia) supplied to the armature, and voltage drop (Va) across the armature circuit, and armature circuit electrical resistance (Ra); representing Ia and Ra as voltages; representing, by analog circuitry, mathematical functions expressing at least a portion of the mechanical output power of the armature and at least a portion of the rotational speed of the armature; providing the voltage representations of Va, Ra and Ia to the analog circuitry; and generating a torque factor output from the analog circuitry, which torque factor is representative of the mechanical output torque delivered by the DC motor armature multiplied by a constant.

Claim 30

Dependent Claim 133 words

Method of monitoring the torque delivered by a DC electric motor which motor includes at least an armature shaft and an armature within an armature circuit, said method comprising the steps of: monitoring current (Ia) supplied to the armature, and voltage drop (Va) across the armature circuit, and armature circuit electrical resistance (Ra); representing Ia and Ra as voltages; representing, by analog circuitry, mathematical functions expressing at least a portion of the mechanical output power of the armature and at least a portion of the rotational speed of the armature; providing the voltage representations of Va, Ra and Ia to the analog circuitry; and generating a torque factor output from the analog circuitry, which torque factor is representative of the mechanical output torque delivered by the DC motor armature multiplied by a constant.

Claim 31

Dependent Claim 69 words

Method of claim 27, wherein said step of representing, by analog circuitry, mathematical functions, comprises, at least, the steps of: representing mechanical output power by the function Ia(Va -IaRa); and representing rotational speed by the function: ##EQU9## wherein Sr, Vr, and Ir are voltages representing, respectively, the name plate rated speed of the motor, name plate rated voltage of the motor and name plate rated current of the motors.

Claim 32

Dependent Claim 50 words

Method of claim 28, further comprising the step of representing, by analog circuitry, the power loss across the motor brushes as a component of the function representing mechanical output power and the voltage drop across the motor brushes as a component of the function representing rotational speed of the armature.

Claim 33

Dependent Claim 27 words

Method of claim 28, further comprising the step of scaling monitored values of Va, Ia and Ra to scaled values thereof for input to the analog circuitry.

Claim 34

Independent Claim 158 words

An apparatus, for representing the value of a target resistance as a voltage for use in an analog circuit, said apparatus comprising; a voltage source; variable resistance means for selectively placing varying resistances within a circuit; a tuning circuit including therein, at least, said voltage source, said variable resistance means, and connection means for connection to the target resistance, wherein said variable resistance means is varied to isolate a matching resistance which matches the target resistance; a resistance representing voltage supply circuit including, at least, voltage output terminals, said variable resistance means, and said voltage source, wherein the voltage drop across said voltage output terminals equals the voltage drop across said matching resistance of said variable resistance means, and switching means for selectively placing said variable resistance means first in said tuning circuit and then in said voltage supply circuit, whereby the target resistance is isolated and then represented as a voltage for input to an analog circuit.

Claim 35

Independent Claim 158 words

An apparatus, for representing the value of a target resistance as a voltage for use in an analog circuit, said apparatus comprising; a voltage source; variable resistance means for selectively placing varying resistances within a circuit; a tuning circuit including therein, at least, said voltage source, said variable resistance means, and connection means for connection to the target resistance, wherein said variable resistance means is varied to isolate a matching resistance which matches the target resistance; a resistance representing voltage supply circuit including, at least, voltage output terminals, said variable resistance means, and said voltage source, wherein the voltage drop across said voltage output terminals equals the voltage drop across said matching resistance of said variable resistance means, and switching means for selectively placing said variable resistance means first in said tuning circuit and then in said voltage supply circuit, whereby the target resistance is isolated and then represented as a voltage for input to an analog circuit.

Claim 36

Dependent Claim 12 words

Apparatus of claim 31, wherein said tuning circuit comprises a Wheatstone bridge.

Claim 37

Dependent Claim 48 words

Apparatus of claim 31 wherein said resistance detecting means further comprises, at least, first scaling means for assuring a representative voltage output at said voltage output terminals of said voltage supply circuit is in the ratio of 1 ohm of target resistance equals one millivolt of voltage output.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1992-12-25	1993-06-26	1993-12-26	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1996-12-25	1997-06-26	1997-12-26	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2000-12-25	2001-06-26	2001-12-26	$7700.00	Window Closed / Lapsed

DC motor operated valve remote monitoring system

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