Control systems for gates and the like including a motor overload monitoring circuit

Claim 2

Apparatus for controlling the current delivered through an electrical motor, comprising: means for producing a measured level of voltage proportionate to the magnitude of current flowing through said motor; means for generating a first reference level of voltage; means coupled with said producing means and said generating means for comparing the magnitude of said first reference level of voltage with said measured level of voltage and for producing a first output signal when said measured level exceeds said first reference level; means for generating a second reference level of voltage; means for comparing the magnitude of said second reference level of voltage with said measured level of voltage and for producing a second output signal when said measured level exceeds said second reference level; and, means responsive to either of said first and second output signals for interrupting delivery of electrical current to said motor.

Claim 3

The apparatus of claim 1, wherein said producing means includes a resistor adapted to be coupled between a source of electrical power and said motor.

Claim 4

The apparatus of claim 1, wherein said producing means includes an electro-optical coupling device adapted to be coupled between a source of electrical power and said motor.

Claim 5

The apparatus of claim 1, wherein said means for generating said first reference level includes means for manually adjusting said first reference level of voltage.

Claim 6

The apparatus of claim 4, wherein said means for manually adjusting includes a manually variable resistance and said means for generating said first reference level further includes a comparator having a first input adapted to be coupled with a source of voltage and a second input adapted to be coupled with said means for manually adjusting.

Claim 7

The apparatus of claim 3, wherein said producing means includes a comparator having an input coupled with said electro-optical coupling device and an output coupled with first comparing means.

Claim 8

The apparatus of claim 6, including means for automatically adjusting said first reference level of voltage in response to changes in the ambient temperature, said means for automatically adjusting including a thermistor.

Claim 9

The apparatus of claim 1, including means coupled with each of said comparing means for gating said first and second output signals.

Claim 10

The apparatus of claim 8, wherein said gating means includes a OR gate coupled between said interrupting means and said first and second comparing means.

Claim 11

The apparatus of claim 1, including means responsive to either of said first and second output signals for providing an indication that said measured level has exceeded one of said first and second reference levels.

Claim 12

The apparatus of claim 1, wherein said interrupting means includes at least one bistable circuit element.

Claim 13

The apparatus of claim 1, including a varistor element adapted to be coupled between said motor and a source of electrical power.

Claim 14

The apparatus of claim 1, including means for inhibiting the delivery of said first output signal to said interrupting means for a preselected time period.

Claim 15

The apparatus of claim 13, wherein said inhibiting means includes a capacitor.

Claim 16

A control system for use with a bidirectional gate driven by a reversible electric motor, comprising: selectively operable switch means for producing control signals to operate said gate; means responsive to said control signals for selectively energizing said motor; and, means for disabling said energizing means when the level of electrical current flowing through said motor exceeds a prescribed level, whereby to prevent current overload of said motor, said disabling means including (1) means for producing a measured level of voltage proportionate to the magnitude of current flowing through said motor, (2) means for generating a first reference level of voltage, said generating means including a first comparator having a pair of inputs, said producing means including a second comparator having an output, (3) first means coupled with said producing means and said generating means for comparing the magnitude of said first reference level of voltage with said measured level of voltage and for producing a first output signal when said measured level exceeds said first reference level, and, means responsive to said first output signal for interrupting the delivery of electrical current to said motor.

Claim 17

A control system for use with a bidirectional gate driven by a reversible electric motor, comprising: selectively operable switch means for producing control signals to operate said gate; means responsive to said control signals for selectively energizing said motor; and, means for disabling said energizing means when the level of electrical current flowing through said motor exceeds a prescribed level, whereby to prevent current overload of said motor, said disabling means including (1) means for producing a measured level of voltage proportionate to the magnitude of current flowing through said motor, (2) means for generating a first reference level of voltage, said generating means including a first comparator having a pair of inputs, said producing means including a second comparator having an output, (3) first means coupled with said producing means and said generating means for comparing the magnitude of said first reference level of voltage with said measured level of voltage and for producing a first output signal when said measured level exceeds said first reference level, and, means responsive to said first output signal for interrupting the delivery of electrical current to said motor.

Claim 18

The system of claim 15, wherein said disabling means includes temperature responsive means connected with said generating means for automatically adjusting said first reference level of voltage in response to changes in the ambient temperature.

Claim 19

The system of claim 15, wherein said producing means includes a resistor adapted to be coupled between a source of electrical power and said motor.

Claim 20

The system of claim 15, wherein said producing means includes an electro-optical coupling device adapted to be coupled between a source of electrical power and said motor.

Claim 21

The system of claim 15, wherein said generating means includes means for manually adjusting said first reference level of voltage.

Claim 22

The system of claim 19, wherein said means for manually adjusting includes a manually variable resistance.

Claim 23

The system of claim 15, including temperature responsive means connected with said generating means for automatically adjusting said first reference level of voltage in response to changes in the ambient temperature, said means for automatically adjusting including a thermistor.

Claim 24

The system of claim 15 including: means for generating a second reference level of voltage; and, means coupled with said producing means and said means for generating a second reference level for comparing the magnitude of said second reference level of voltage with said measured level of voltage and for producing a second output signal when said measured level exceeds said second reference level.

Claim 25

The system of claim 22, including means coupled with said first and second comparing means for gating said first and second output signals.

Claim 26

The system of claim 23, wherein said gating means includes an OR gate coupled between said interrupting means and said first and second comparing means.

Claim 27

The system of claim 15, including means for inhibiting the delivery of said first output signal to said interrupting means for a preselected time period.

Claim 28

The system of claim 15, wherein said energizing means includes: a gate opening circuit having an output connected to said motor; a gate closing circuit having an output connected to said motor; and, circuit means coupled between said disabling means and said opening and closing circuits for controlling said gate opening and gate closing circuits.

Claim 29

The system of claim 26, wherein said opening and closing circuits each include a bistable circuit element having a reset input under control of said disabling means.

Claim 30

The system of claim 27, wherein said opening and closing circuits each include an electrical switch adapted to couple said motor with a source of electrical power and controlled by the corresponding bistable circuit element.