Process control system

Claim 3

The method of claim 1 in which the first-named step comprises, generating a train of pulses, each pulse of said train occurring when said cyclical power source voltage is substantially at its maximum amplitude, enabling a plurality of bistable devices, each associated with one of said process control parameter sensors, to generate an output signal in accordance with the condition of each of said process control parameter sensors, on the occurrence of one of said train of pulses.

Claim 4

The method of claim 2 wherein thE steps of storing said sensed parameters signals and the step of deriving revised process control commands comprise, generating a second train of pulses, each pulse of said second train of pulses occurring subsequent to the time said cyclical power source voltage is substantially at its maximum amplitude but prior to the time said cyclical power source voltage is substantially at its minimum amplitude, enabling the generation of revised process control commands on the occurrence of one of said second train of pulses.

Claim 5

In the method of claim 3 wherein the step of executing said revised process control commands comprises, generating a third train of pulses, each pulse of said third train of pulses occurring at the time said cyclical power source voltage is substantially at its minimum amplitude, enabling a plurality of second bistable devices, each associated with one of a plurality of power switch means, to generate output signals at the time of occurrence of one of said third train of pulses.

Claim 6

A process control system comprising, a cyclical power source, a plurality of process control parameter sensors, means responsive to said power source and operative when said cyclical power source voltage is substantially at its maximum amplitude to sense process control parameters, a process control command generator operatively associated with said process control parameter sensors and responsive to said power source to generate revised process control commands subsequent to the time said cyclical power source voltage is substantially at its maximum amplitude but prior to the time said cyclical power source voltage is substantially at its minimum amplitude, and process control command execution means responsive to said power source for executing said revised process control commands at the time said cyclical power source voltage is substantially at its minimum amplitude.

Claim 7

A process control system comprising, a cyclical power source, a plurality of process control parameter sensors, means responsive to said power source and operative when said cyclical power source voltage is substantially at its maximum amplitude to sense process control parameters, a process control command generator operatively associated with said process control parameter sensors and responsive to said power source to generate revised process control commands subsequent to the time said cyclical power source voltage is substantially at its maximum amplitude but prior to the time said cyclical power source voltage is substantially at its minimum amplitude, and process control command execution means responsive to said power source for executing said revised process control commands at the time said cyclical power source voltage is substantially at its minimum amplitude.

Claim 8

In the system of claim 5 wherein said process control parameter sensors comprise, a plurality of bistable devices, each of said bistable devices associated with one of said process control parameter sensors, a clock signal generator controlled by said cyclical power source means and adapted to generate a train of pulses, each pulse of said train of pulses occurring when said cyclical power source mean voltage is substantially at its maximum amplitude, said clock signal generator cooperating with said plurality of bistable devices so that said bistable devices are operative to product output signals only at the time of occurrence of one of said train of pulses.

Claim 9

The system of claim 6 which further includes, second clock signal generator means controlled by said cyclical power source means to produce a second train of pulses, each pulse of said second train of pulses occurring subsequent to the time said cyclical power source voltage is substantially at its maximum amplitude but prior to the time said cyclical power source voltage is substantially at its minimum amplitude, said second clock signal generating means cooperating with said process control command generator so that said process control command generator is operative to generate revised process control commands only at the time of one of said second train of pulses.

Claim 10

The system of claim 7 in which said process control command execution means comprises, third clock signal generator means controlled by said cyclical power source means to generate a third train of pulses each pulse of said third train of pulses occurring at the time said cyclical power source voltage is substantially at its minimum amplitude, a plurality of second bistable devices, each of said second bistable devices associated with one of a plurality of power switch means, each of said plurality of second bistable devices being controlled by said third clock signal generator means to produce an output only at the time of occurrence of one of said third train of pulses.

Claim 11

The system of claim 8 which further includes reset means to initialize said system during the initial application of power to the system comprising, a first plurality of gates jointly controlled by said plurality of bistable devices and said reset means, a second plurality of gates jointly controlled by said plurality of second bistable devices and said reset means, said reset means producing an output signal when the voltage applied to said system has risen to a predetermined value, said first and second plurality of gates inhibiting the passage of signals until such time as said reset means produces an output signal.

Claim 12

A substantially noise-immune process control system comprising, an alternating-current power source, at least one controlled device being operable between at least two differently distinctive control conditions in response to a control signal applied thereto, at least one condition responsive means operable between at least two differently distinctive states in dependence upon at least one condition of a process controlled by said process control system, means controlled at least in part by said power source for rendering said condition responsive means responsive to said process condition only at the time, at least once on each cycle of the alternating-current source, that the waveform of the voltage of said power source is substantially at its maximum amplitude, whereby said condition responsive means responds periodically to indicate a change in the respective process condition indicated thereby at a time of minimum likelihood of interference by noise signals, control signal generating means being responsive in part to said power source for generating a new control signal for each controlled device at least one each cycle of said alternating-current source at a predetermined time subsequent to the time its waveform has attained its maximum amplitude but prior to the time it has attained a zero amplitude, said control signal generating means being also responsive in part to the then-operated conditions of said condition responsive means at the time said new control signals are generated, whereby sufficient time elapses subsequent to operation of each said condition responsive means to stabilize its output means and thereby reduce generation of erroneous control signals, operating means for said controlled devices controlled in part by said power source for controlling each said controlled device to a distinctive control condition only at the time the waveform of said power source is substantially at zero amplitude, said operating means being further responsive at least in part to the control signals most recently generated by said control signal generating means when controlling said controlled devices, whereby the generation of noise signals resulting from the operation of said controlled devices is minimized and sufficient time is provided between operation of each said controlled device and the time that each said condition responsive means is next rendered responsive to allow noise signals produced by operation of said controlled device to dissipate, thereby minimizing the effect of noise signals produced by said operating means on said condition responsive means.

Claim 13

A substantially noise-immune process control system comprising, an alternating-current power source, at least one controlled device being operable between at least two differently distinctive control conditions in response to a control signal applied thereto, at least one condition responsive means operable between at least two differently distinctive states in dependence upon at least one condition of a process controlled by said process control system, means controlled at least in part by said power source for rendering said condition responsive means responsive to said process condition only at the time, at least once on each cycle of the alternating-current source, that the waveform of the voltage of said power source is substantially at its maximum amplitude, whereby said condition responsive means responds periodically to indicate a change in the respective process condition indicated thereby at a time of minimum likelihood of interference by noise signals, control signal generating means being responsive in part to said power source for generating a new control signal for each controlled device at least one each cycle of said alternating-current source at a predetermined time subsequent to the time its waveform has attained its maximum amplitude but prior to the time it has attained a zero amplitude, said control signal generating means being also responsive in part to the then-operated conditions of said condition responsive means at the time said new control signals are generated, whereby sufficient time elapses subsequent to operation of each said condition responsive means to stabilize its output means and thereby reduce generation of erroneous control signals, operating means for said controlled devices controlled in part by said power source for controlling each said controlled device to a distinctive control condition only at the time the waveform of said power source is substantially at zero amplitude, said operating means being further responsive at least in part to the control signals most recently generated by said control signal generating means when controlling said controlled devices, whereby the generation of noise signals resulting from the operation of said controlled devices is minimized and sufficient time is provided between operation of each said controlled device and the time that each said condition responsive means is next rendered responsive to allow noise signals produced by operation of said controlled device to dissipate, thereby minimizing the effect of noise signals produced by said operating means on said condition responsive means.