US3890494A — Apparatus and method for altering process control…

Claim 1

Independent Claim 124 words

Apparatus for altering a process control system in response to an interruption in the supply of electrical power to said process control system, said apparatus comprising: a timing means having trigger input means for accepting a preselected trigger signal and timed output means for producing a timed output signal of preselected duration in response to said preselected trigger signal, trigger signal generatng means for sensing an interruption in power provided by a first power supply means to said process control system and generating said preselected trigger signal in response to the termination of said interruption, and process control system override means for overriding at least a portion of said process control system in response to, and for the duration of, said timed outpt signal.

Claim 2

Dependent Claim 124 words

Apparatus for altering a process control system in response to an interruption in the supply of electrical power to said process control system, said apparatus comprising: a timing means having trigger input means for accepting a preselected trigger signal and timed output means for producing a timed output signal of preselected duration in response to said preselected trigger signal, trigger signal generatng means for sensing an interruption in power provided by a first power supply means to said process control system and generating said preselected trigger signal in response to the termination of said interruption, and process control system override means for overriding at least a portion of said process control system in response to, and for the duration of, said timed outpt signal.

Claim 3

Dependent Claim 25 words

Apparatus in accordance with claim 1 wherein said first power supply means provides power for operating said trigger signal generating means and said timing means.

Claim 4

Dependent Claim 51 words

Apparatus in accordance with claim 2 wherein said timing means comprises a timing capacitor which begins charging in response to receipt of said preselected trigger signal at said trigger input means of said timing means and which, upon charging to a preselected threshold voltage, causes said timed output signal to terminate.

Claim 5

Dependent Claim 40 words

Apparatus in accordance with claim 3 wherein power for charging said timing capacitor is provided by a second power supply means and wherein power for operating the remainder of said timing means is provided by said first power supply means.

Claim 6

Dependent Claim 103 words

Apparatus in accordance with claim 3 wherein said first power supply means is a first DC power supply, wherein said trigger signal generating means comprises a trigger capacitor connected in series with a first resistor with the series combination of said first resistor and said trigger capacitor being connected between the positive and negative terminals of said first DC power supply, wherein said trigger input means of said timing means is connected to the common connection between said first resistor and said trigger capacitor, and wherein said preselected trigger signal comprises the voltage aCross said trigger capacitor being less than a preselected voltage.

Claim 7

Dependent Claim 76 words

Apparatus in accordance with claim 5 wherein said trigger signal generating means additionally comprises a first diode in series with a second resistor, with the series combination of said first diode and said second resistor being connected in parallel with said first resistor and with the polarity of said first diode being selected to prohibit charging of said trigger capacitor through said second resistor and to permit discharging of said trigger capacitor through said second resistor.

Claim 8

Dependent Claim 24 words

Apparatus in accordance with claim 6 additionally comprising reset means for increasing the rate at which said timing capacitor charges to said threshold voltage.

Claim 9

Dependent Claim 21 words

Apparatus in accordance with claim 7 wherein power for charging said timing capacitor is provided by a second DC power supply.

Claim 10

Dependent Claim 32 words

Apparatus in accordance with claim 8 additionally comprising output signal conditioning means for accepting said timed output signal and generating an inverted signal suitable for operating said process control system override means.

Claim 11

Dependent Claim 92 words

Apparatus in accordance with claim 9 wherein said timed output signal is a substantially constant voltage of preselected duration with said timed output means being at substantially ground potential when said timed output signal is not being produced and wherein said inverted signal is at substantially ground potential during the time that the constant voltage of said timed output signal is supplied to said output signal conditioning means, with said inverted signal being a substantially constant voltage when said first DC power supply is activated and said timed output means is grounded.

Claim 12

Dependent Claim 15 words

Apparatus in accordance with claim 2 wherein said process control system comprises a digital programmer.

Claim 13

Dependent Claim 62 words

Apparatus in accordance with claim 11 wherein said digital programmer is in control of at least one chromatographic analyzer and wherein said process control system override means comprises means for preventing delivery of a sample to said at least one chromatographic analyzer, means for backflushing the sample column of said at least one chromatographic analyzer, and means for resetting said digital programmer.

Claim 14

Independent Claim 90 words

A method for altering a process control system in response to an interruption in the supply of electrical power to said process control system by a first power supply means, said method comprising: generating a trigger signal in response to the return of electrical power to said process control system at the end of a power interruption, producing a timed output signal in response to said trigger signal, overriding at least a portion of said process control system in response to, and for the duration of, said timed output signal.

Claim 15

Independent Claim 90 words

A method for altering a process control system in response to an interruption in the supply of electrical power to said process control system by a first power supply means, said method comprising: generating a trigger signal in response to the return of electrical power to said process control system at the end of a power interruption, producing a timed output signal in response to said trigger signal, overriding at least a portion of said process control system in response to, and for the duration of, said timed output signal.

Claim 16

Dependent Claim 47 words

A method in accordance with claim 13 wherein generating said trigger signal comprises at least partially discharging a trigger capacitor in response to a power interruption of preselected magnitude or duration, recharging said trigger capacitor in response to the return of power to said process control system.

Claim 17

Dependent Claim 48 words

A method in accordance with claim 14 wherein producing said timed output signal comprises comparing the voltage across said trigger capacitor to a reference voltage and beginning production of said timed output signal in response to said voltage across said trigger capacitor being less than said reference voltage.

Claim 18

Dependent Claim 23 words

A method in accordance with claim 15 wherein discharging said trigger capacitor is accomplished at a faster rate than recharging said trigger capacitor.

Claim 19

Dependent Claim 53 words

A method in accordance with claim 16 wherein said reference voltage is generated by dividing the voltage supplied by said first power supply means utilizing a plurality of resistors connected in series across said first power supply means and utilizing the voltage between two of said plurality of resistors as said reference voltage.

Claim 20

Dependent Claim 125 words

A method in accordance with claim 17 wherein the duration of said timed output signal is dEtermined by the time required to charge a timing capacitor to a preselected threshold voltage utilizing a second power supply means as a voltage source for charging said timing capacitor and wherein overriding at least a portion of said process control system comprises resetting a digital programmer which controls the operation of at least one chromatographic analyzer backflushing the sample column of said analyzer and inhibiting the taking of additional samples by said analyzer during the production of said timed output signal, said method additionally comprising returning control of said at least one chromatographic analyzer to said programmer when said timing capacitor has charged to said preselected threshold voltage.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-06-16	1978-12-16	1979-06-17	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-06-16	1982-12-16	1983-06-17	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-06-16	1986-12-16	1987-06-17	$7700.00	Window Closed / Lapsed

Apparatus and method for altering process control in response to a power interruption

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