Signal detector circuit with gain control method

Claim 2

A monitoring apparatus for monitoring the occurrence of a plurality of events in a cyclical process, comprising event transducer means for detecting the occurrence of such events in such process, said event transducer means comprising means for producing an input signal which may vary in an unknown manner upon the occurrence of each event, a signal control apparatus including output means for producing an output signal, changing means for receiving such input signal and causing said output means to produce such output signal at a predetermined magnitude in response to receipt of such input signal, and control means for controlling said changing means in discrete steps that are, respectively, proportional to the magnitude of at least one of such input and output signals, progress transducer means for detecting the progress of such process, and search means for sensing whether respective events occur at expected positions in the progress of such process.

Claim 3

The apparatus of claim 1, said input means comprising amplifier means for amplifying such input signal, such input signal comprising a pulse signal, and said input means further comprising means for filtering such pulse signal and delivering the same to said changing means.

Claim 4

The apparatus of claim 1, said input means comprising means for receiving a pulse modulated AC signal, filter means for filtering such pulse modulated AC signal to produce therefrom a DC pulse signal as such input signal, said output means comprising means for producing such output signal as an output DC pulse signal, and said changing means and control means being cooperative to strive to maintain the maximum amplitude of such output DC pulse signal at such predetermined magnitude.

Claim 5

The apparatus of claim 3, such predetermined magnitude comprising a range of magnitudes between minimum and maximum magnitudes.

Claim 6

The apparatus of claim 1, said changing means comprising means for amplifying such input signal to produce such output signal and means for changing the proportional relation between such input and output signals in incremental steps of different magnitude.

Claim 7

The apparatus of claim 5, said means for changing comprising a digitally responsive device, and said control means comprising means for delivering parallel digital information to said digitally responsive device substantially instantaneously to effect such stepwise changing.

Claim 8

The apparatus of claim 6, said means for amplifying comprising an amplifier and said digitally responsive device comprising a resistance ladder network for changing the gain of said amplifier.

Claim 9

The apparatus of claim 6, said control means comprising analog to digital converter means for producing output digital information proportionally representative of the magnitude of such output signal and computer means for monitoring the magnitude of such output digital information and in response thereto to deliver digital information to said digitally responsive device.

Claim 10

The apparatus of claim 6, said control means comprising analog to digital converter means for producing parallel digital output information proportionally representative of the magnitude of such output signal, and further comprising display means for visually displaying the value of such parallel digital output information, said display means comprising a plurality of light output means coupled to have a number of the same energized to deliver a visual output in response to respective logic levels of the signal comprising such parallel digital output information.

Claim 11

The apparatus of claim 1, said changing means comprising an amplifier and said control means comprising means for changing the gain of said amplifier.

Claim 12

A monitoring apparatus for monitoring the occurrence of a plurality of events in a cyclical process, comprising event transducer means for detecting the occurrence of such events in such process, said event transducer means comprising means for producing an input signal which may vary in an unknown manner upon the occurrence of each event, a signal control apparatus including output means for producing an output signal, changing means for receiving such input signal and causing said output means to produce such output signal at a predetermined magnitude in response to receipt of such input signal, and control means for controlling said changing means in discrete steps that are, respectively, proportional to the magnitude of at least one of such input and output signals, progress transducer means for detecting the progress of such process, start-stop control means for starting and stopping such process, and computer means for sensing whether respective events occur at expected positions in the progress of such process, said computer means being coupled to said start-stop control means to operate the same to stop such process when a prescribed number of events has been missed.

Claim 13

A monitoring apparatus for monitoring the occurrence of a plurality of events in a cyclical process, comprising event transducer means for detecting the occurrence of such events in such process, said event transducer means comprising means for producing an input signal which may vary in an unknown manner upon the occurrence of each event, a signal control apparatus including output means for producing an output signal, changing means for receiving such input signal and causing said output means to produce such output signal at a predetermined magnitude in response to receipt of such input signal, and control means for controlling said changing means in discrete steps that are, respectively, proportional to the magnitude of at least one of such input and output signals, progress transducer means for detecting the progress of such process, start-stop control means for starting and stopping such process, and computer means for sensing whether respective events occur at expected positions in the progress of such process, said computer means being coupled to said start-stop control means to operate the same to stop such process when a prescribed number of events has been missed.

Claim 14

The apparatus of claim 1 or 11, said event transducer means comprising means for producing an event electrical signal upon the occurrence of each event, and said signal control apparatus comprising detector circuit means for detecting such event electrical signals and gain control circuit means for striving maintain the magnitude of at least one of such event electrical signals and signals representative of the occurrence thereof at a predetermined magnitude.

Claim 18

The apparatus of claim 15, further comprising display means for displaying the magnitude of such output signal.

Claim 19

The apparatus of claim 15, said output means further comprising analog to digital converter means for converting the output from said amplifier to a digital signal representative of the magnitude thereof.

Claim 22

The apparatus of claim 19, said control means comprising analog to digital converter means for producing parallel digital output information proportionally representative of the magnitude of such output signal, and further comprising display means for visually displaying the value of such parallel digital output information, said display means comprising a plurality of light output means coupled to have a number of the same energized to deliver a visual output in response to respective logic levels of the signal comprising such parallel digital output information.

Claim 25

The method of claim 21, said amplifying comprising using an amplifier to amplify such input signal to produce such output signal, and said controlling comprising controlling the gain of said amplifier.

Claim 26

The method of claim 22, said controlling the gain comprising changing the gain in incremental steps of different magnitude in dependence on the magnitude of at least one of such input and output signals.

Claim 27

The method of claim 23, said controlling the gain comprising changing the gain in incremental steps of different magnitude in dependence on the difference between such predetermined magnitude and the magnitude at least one of such input and output signals.

Claim 28

The method of claim 22, further comprising sensing whether the magnitude of such output signal is beyond a predetermined magnitude and when the same is affirmatively sensed at least temporarily preventing any change in such gain.

Claim 29

The method of claim 25, wherein said sensing whether the magnitude of such output signal is beyond a predetermined magnitude comprises sensing whether such output signal is less than a minimum value.

Claim 30

The method of claim 22, further comprising limiting the maximum gain of such amplifier.

Claim 31

The method of claim 22, said controlling the gain comprising reducing such gain when the magnitude of such output signal exceeds a predetermined value.

Claim 32

The method of claim 22, said controlling the gain comprising maintaining substantially constant such gain when the magnitude of such output signal is within a predetermined desired range.

Claim 33

The method of claim 22, further comprising displaying the value of such output signal.

Claim 34

The method of claim 22, wherein such input signal comprises a pulse modulated AC signal, and further comprising operating on such pulse modulated AC signal to produce a DC pulse signal, and said amplifying comprising amplifying such DC pulse signal to produce such output signal as a DC pulse.

Claim 35

The method of claim 22, said controlling comprising controlling the gain in response to the difference in magnitude between such predetermined magnitude and the magnitude of at least one of such input and output signals.

Claim 36

The method of claim 21, wherein such process is the operation of an endless type conveyor belt, said step of detecting the occurrence comprises checking specified portions of such conveyor belt as they pass a rip detector station to find a rip in the conveyor belt whereby an undetected event at its expected position during said sensing step may be interpreted as a rip in the conveyor belt, said checking comprises coupling a signal from a transmitter to a receiver each time an event occurs to produce such input signal, and said controlling comprising controlling to maintain the magnitude of such output signal at approximately such predetermined magnitude as the efficiency of such coupling and, therefore, the magnitude of such input signal varies.

Claim 37

A signal control apparatus, comprising input means for receiving an input signal, output means for producing an output signal, changing means for receiving such input signal and causing said output means to produce such output signal at a predetermined magnitude in response to receipt of such input signal, and control means for controlling said changing means in steps that are proportional, respectively, to the magnitude of at least one of such input and output signals, said control means comprising means for controlling in response to the difference between such predetermined magnitude and the magnitude of such output signal as represented by an aveage value thereof.

Claim 38

A signal control apparatus, comprising input means for receiving an input signal, output means for producing an output signal, changing means for receiving such input signal and causing said output means to produce such output signal at a predetermined magnitude in response to receipt of such input signal, and control means for controlling said changing means in steps that are proportional, respectively, to the magnitude of at least one of such input and output signals, said control means comprising means for controlling in response to the difference between such predetermined magnitude and the magnitude of such output signal as represented by an aveage value thereof.

Claim 39

A monitoring apparatus for monitoring the occurrence of a plurality of events in a cyclical process, comprising event transducer means for detecting the occurrence of such events in such process, said event transducer means comprising means for producing an input signal upon the occurrence of each event, a signal control apparatus including output means for producing an output signal, changing means for receiving such input signal and causing said output means to produce such output signal at a predetermined magnitude in response to receipt of such input signal, and control means for controlling said changing means in steps that are proportional, respectively, to the magnitude of at least one of such input and output signals, progress transducer means for detecting the progress of such process, and search means for sensing whether respective events occur at expected positions in the progress of such process, said control means comprising means for controlling in response to the difference between such predetermined magnitude and the magnitude of at least one of such input and output signals, said control means comprising means for controlling in response to the magnitude of such output signal as represented by an average value thereof.

Claim 40

A monitoring apparatus for monitoring the occurrence of a plurality of events in a cyclical process, comprising event transducer means for detecting the occurrence of such events in such process, said event transducer means comprising means for producing an input signal upon the occurrence of each event, a signal control apparatus including output means for producing an output signal, changing means for receiving such input signal and causing said output means to produce such output signal at a predetermined magnitude in response to receipt of such input signal, and control means for controlling said changing means in steps that are proportional, respectively, to the magnitude of at least one of such input and output signals, progress transducer means for detecting the progress of such process, and search means for sensing whether respective events occur at expected positions in the progress of such process, said control means comprising means for controlling in response to the difference between such predetermined magnitude and the magnitude of at least one of such input and output signals, said control means comprising means for controlling in response to the magnitude of such output signal as represented by an average value thereof.

Claim 41

A monitoring apparatus for monitoring the occurrence of a plurality of events in a cyclical process, comprising event transducer means for detecting the occurrence of such events in such process, said event transducer means comprising means for producing an input signal upon the occurrence of each event, a signal control apparatus including output means for producing an output signal, changing means for receiving such input signal and causing said output means to produce such output signal at a predetermined magnitude in response to receipt of such input signal, and control means for controlling said changing means in steps that are proportional, respectively, to the magnitude of at least one of such input and output signals, progress transducer means for detecting the progress of such process, start-stop control means for starting and stopping such process, and computer means for sensing whether respective events occur at expected positions in the progress of such process, said computer means being coupled to said start-stop control means to operate the same to stop such process when a prescribed number of events has been missed, said control means comprising means for controlling in response to the difference between such predetermined magnitude and the magnitude of at least one of such input and output signals, said control means comprising means for controlling in response to the magnitude of such output signal as represented by an average value thereof.

Claim 42

A monitoring apparatus for monitoring the occurrence of a plurality of events in a cyclical process, comprising event transducer means for detecting the occurrence of such events in such process, said event transducer means comprising means for producing an input signal upon the occurrence of each event, a signal control apparatus including output means for producing an output signal, changing means for receiving such input signal and causing said output means to produce such output signal at a predetermined magnitude in response to receipt of such input signal, and control means for controlling said changing means in steps that are proportional, respectively, to the magnitude of at least one of such input and output signals, progress transducer means for detecting the progress of such process, start-stop control means for starting and stopping such process, and computer means for sensing whether respective events occur at expected positions in the progress of such process, said computer means being coupled to said start-stop control means to operate the same to stop such process when a prescribed number of events has been missed, said control means comprising means for controlling in response to the difference between such predetermined magnitude and the magnitude of at least one of such input and output signals, said control means comprising means for controlling in response to the magnitude of such output signal as represented by an average value thereof.