Door Operator System

The present invention pertains to a door operator system including a motor driven door operator and a controller therefor, particularly adapted for opening and closing upward acting garage doors and the like.

Substantial developments have been carried out in the art of operators and control systems associated therewith for remotely controlling the opening and closing of upward acting sectional or one piece garage doors.

There has been a continuing need to provide garage door operators and control systems therefor which minimize the hazards associated with opening and closing the door, and provide for opening the door rapidly so that the user may make a rapid entry or exit with respect to the garage, or other structure, while providing reduced stress on the operator and the door. There has also been a need to achieve operation automatically by remote control with substantial reliability. These needs have posed certain problems in the provision of door operators and control systems associated therewith.

Still other problems associated with garage door operator systems include the desire to provide an operator and control system associated therewith which can be easily and accurately adjusted by the user to automatically stop or reverse the direction of movement of the door in the event of encountering an obstruction, detect whether or not the operator is controlling a sectional type door or a one piece or so-called California type door and provide for variable speed control of the door opening and closing cycle to provide for rapid opening of the door at a controlled rate of speed with acceleration and deceleration phases and acceptable reduced closing speeds of the door, again with acceleration and deceleration phases of the closing cycle. All of these features are desired to be incorporated in a door operator and control system associated therewith which requires minimal effort to install and establish operation thereof.

It is to all of these ends that the present invention has been developed.

The present invention provides an improved door operator and control system for remote controlled opening and closing of a door, particularly a sectional or one piece upward acting garage door.

In accordance with one aspect of the present invention, a door operator is provided which is characterized by a reversible DC electric drive motor that is driven directly from rectified AC line voltage and is directly coupled to a door actuating drive mechanism. The DC motor is supplied with a pulse width modulated voltage power signal to achieve variable speed and power requirements. Motor speed is determined through the use of an encoder, preferably including an optical signal interrupt wheel mounted directly on the motor output shaft. A pulse type signal generated by the encoder is used to determine changes in motor speed, total travel of the operator and door for purposes of detecting the type of door to which the operator is connected and to provide for speed control in the door opening and closing modes.

In accordance with another aspect of the present invention, a door operator and control system therefor is provided which is operable to determine whether or not the operator is connected to a sectional type upward acting door or a one piece or so-called California-type door and to adjust the operating speed in accordance with the type of door being acted on.

Still further, the present invention provides a control system for a door operator which automatically controls movement of the door from a closed position to an open position at a speed greater than movement from an open position to a closed position. Moreover, the present invention also provides a control system for an upward acting door operator which is operable to sense current flow to the operator motor and to utilize limit signals proportional to current flow as obstruction detection signals to effect stopping and/or reversing the direction of movement of the door in response to selectively settable current limits.

The present invention yet further provides an improved method for operating an upward acting door to move between open and closed positions.

Those skilled in the art will further appreciate the above-mentioned advantages and superior features of the invention, together with other important aspects thereof upon reading the detailed description which follows in conjunction with the drawings.

FIG. 1 is a longitudinal central section view, in somewhat schematic form, of a door operator in accordance with the present invention;

FIG. 1A is an exploded perspective view of certain components of the operator shown in FIG. 1;

FIG. 1B is a perspective view of a motor support member for the operator;

FIG. 2 is a transverse section view taken generally along the line 2--2 of FIG. 1;

FIGS. 3A and 3B are circuit diagrams of the main controller unit for the door operator control system of the present invention;

FIG. 4 is a schematic diagram of the motor control circuit for the operator motor; and

FIG. 5 is a state diagram for the operator control system of the present invention.

In the description which follows like parts are marked throughout the specification and drawing with the same reference numerals, respectively. The drawing figures are not necessarily to scale and certain elements are shown in somewhat generalized or schematic form in the interest of clarity and conciseness.

Referring to FIGS. 1, 1A and 2, there is illustrated a door operator, generally designated by the numeral 10, for moving an upward acting sectional or one piece garage door between open and closed positions. One piece or so-called California-type doors as well as sectional doors are usually adapted to be guided between open and closed positions on opposed guide rails or tracks. Such doors are well known and a further description of the respective types of doors is not believed to be necessary to practice the present invention. The operator 10 is, in some respects, an exemplary embodiment in that it is characterized by an elongated extruded metal rail member 12 which, as shown in FIG. 2, comprises a transverse upper flange part 12a, a depending web 12b and an integral, somewhat tubular boss 12c with opposed longitudinal laterally projecting flange portions 12d and 12e. The tubular boss 12c is adapted to retain therein an elongated somewhat inverted U-shaped bearing liner member 14 for journalling an elongated power screw 16 therein. The bearing liner 14 is preferably formed of a suitable bearing material such as Montell 1900 engineering elastomer or equivalent with a silicone additive. The power screw 16 is adapted to be connected to a releasable nut or rack member 18 disposed on a carriage member 20 which is supported for sliding movement on the rail 12 by the lateral flanges 12d and 12e. The carriage 20 is adapted to be connected to a suitable linkage 21, FIG. 1, connected to a door 21a in a conventional manner. The nut or rack member 18 is also adapted to be released from operable engagement with the screw 16 when desired, also in a somewhat conventional manner. Accordingly, upon rotation of the screw 16 by a motor to be described in further detail herein, the nut or rack 18 and carriage 20 may traverse together linearly along the rail 12 in opposite directions, also in a manner known to those skilled in the art to move the door 21a between open and closed positions.

As shown in FIGS. 1 and 2, the rail 12 supports spaced apart brackets 22 and 24 thereon at substantially opposite ends of the rail, which brackets are adapted to support magnetically actuated reed type switches 23 and 25, respectively, FIG. 1. A permanent magnet 26 is mounted on a suitable boss 27, FIG. 2, on the carriage 20 such that, when the carriage 20 moves into proximity to the switches 23 and 25, respectively, these switches are actuated to effect operation of a controller for the operator 10 to be described in further detail herein. The brackets 22 and 24 may be selectively positioned along the rail 12. However, the bracket 22 is positioned in such a way that when door 21a, connected to the carriage 20, is in a closed position the switch 23 is actuated as a down or door closed limit switch to shutoff power to a motor drivingly connected to the screw 16. Conversely, when the carriage 20 moves into proximity of its magnet 26 to the switch 25, this switch is actuated as an up limit or door open limit switch to also effect shutoff of the door operator motor.

Referring further to FIG. 1, the rail 12 is supported at a distal end 12f by a suitable wall bracket 13 and the rail 12 is supported at its opposite end 12g by a support member 32 for a permanent magnet reversible DC electric drive motor 34. The motor 34 is mounted on the support member 32 and on a support plate 36, FIGS. 1 and 1A, which is adapted to be connected to suitable support structure, not shown, in a conventional manner for upward acting door operators.

The motor 34 includes a rotatable armature shaft 38 rotatably supported in suitable bearings 40 and 42 and directly coupled to the screw 16 by a coupler 44. Directional thrust loads on the screw 16 are taken through a thrust bearing 46 which, together with the coupling 44, is mounted in a suitable bore 33 formed in the support member 32. In FIG. 1, the carriage 20 is shown in a position wherein its movement toward the motor 34 is limited by engagement with a stop member 43, slidably disposed on rail 12 and operable to engage a resilient abutment 48 mounted on the support member 32. Distal end 38a of shaft 38 is connected to an optical signal encoder wheel 52 having a plurality of circumferentially spaced teeth 54 formed thereon and positioned adjacent to a photocell type sensor 56 which is operably associated with the wheel 52 to generate a pulse-type low voltage electrical signal which is directly proportional to incremental rotation of the shaft 38 and the screw 16. Accordingly, a signal generated by the encoder or sensor 56 may be correlated with the position of the carriage 20 and door 21a and also used to determine motor and door operating speed.

As further shown in FIGS. 1 and 1A, the operator 10 includes a suitable housing or cover 60 for the motor 34 and encoder wheel 52, which cover is also adapted to cooperate with the support plate 36 to house a suitable motor control circuit 62, a main controller unit 64 and a radio receiver 66 operably connected to and mounted on the controller unit 64. The motor control circuit 62, the controller unit 64 and the receiver 66 are adapted to be mounted within the cover 60. A suitable garage light or lamp assembly 59 is mounted on cover 60, FIG. 1A, and covered by a molded translucent lens member 61 which is releasably connected to cover 60 by tabs 61a, for example.

Referring further to FIGS. 1 and 1A, the support plate 36 includes opposed longitudinal somewhat channel-shaped flanges 36a and 36b for securing the operator 10 to suitable support structure depending from a garage ceiling or the like. Spaced apart depending tabs 36c of the support plate 36 are operable to be engaged with suitable tabs, not shown, formed on the cover 60 to secure the cover to the support plate. The cover 60 is also releasably secured to the support plate by plural mechanical fasteners 60a, as shown. Still further, the motor 34 is secured to the support member 32 by releasable mechanical fasteners, not shown, and the motor 34 is secured to the support plate 36 by fasteners which are operable to engage an angle shaped mounting bracket 34a and a flange 32a, respectively, on the support member 32. Referring particularly to FIGS. 1 and 1B, the motor support member 32 is advantageously formed as an integral single part casting having a cylindrical hub portion 32b including a bearing bore 32c for receiving the bearing assembly 40. The integrated support member 32 also includes a longitudinally projecting cantilever beam portion 32d which is provided with an elongated longitudinal centrally disposed slot 32e formed therein for receiving the web 12b of rail 12, see FIG. 1, at the end 12g of the rail. Suitable mechanical fasteners 12h project through corresponding bores formed in the beam portion 32d and the web 12b to secure the support member 32 to the rail 12. Accordingly, the support member 32 is advantageously formed as an integral casting and performs several functions as described hereinabove.

Referring now to FIG. 4, the motor control circuit 62 includes a connector 67 adapted to be connected to a source of alternating current (AC) one hundred ten volt electricity via conductors 68a and 68b. The input electrical power via the conductors 68a and 68b is connected via surge protecting varistors 70a and 70b to a step down transformer 72 which is operable to provide 24 volt AC power to a bridge rectifier 74. Rectifier 74 provides 24 volt DC electric power to the circuit 62 and the controller unit 64 by way of a filter capacitor 74a. Twenty-four volt DC power is also supplied to the actuator 76 of a relay 82 for energizing and de-energizing lamp 59 associated with the operator 10. Twenty-four volt DC power is also operable to be supplied to a motor direction reversing relay 78, as shown in FIG. 4.

One hundred ten volt AC line voltage is also supplied to relay 82, a fuse 84 and a motor voltage rectifier 86 to supply DC motor operating voltage to the motor 34 by way of the relay 78. A current limiting resistor 88 prevents current inrush to capacitor 90. Relay coil 92 operates a relay 94 to shunt out the resistor 88 when capacitor 90 is fully charged or energized.

As further shown in FIG. 4, conductors 34a and 34b extend between the relay 78 and the connector 67 and conductor 34a is in circuit with a current sensor comprising a split core transformer 98. Motor current flowing through conductor 34a and the split core transformer 98 induces magnetic flux into the core of the transformer, the strength of which is proportional to the magnitude of motor current. A commercially available Hall effect sensor 100 is interposed in a gap 99 of the transformer core and produces an output voltage signal proportional to the strength of the magnetic field or flux across the gap 99. Accordingly, the output signal from the Hall effect sensor 100 is proportional to the current flowing through the motor 34. Filters 100a and 100b are functional to decouple and stabilize Hall effect sensor 100. The output signal of Hall effect sensor 100 is applied to analog signal inputs of a microcontroller, to be described in further detail herein. This analog signal is converted to a digital signal in the microcontroller where the analog voltage at the microcontroller input pin is converted to a digital signal level between zero and two hundred fifty five, which signal is then applied to an algorithm to determine if the motor is applying a force greater than set by the door operator system, and which is adjustable by the user of the door operator.

The voltage signal imposed on the motor 34 is pulse width modulated by circuitry including an insulated gate bipolar transistor 106 and an insulated gate bipolar transistor driver 108 which receives an input signal from the aforementioned microcontroller via conductor 110 and current limit resistor 112a and pulldown resistor 112b. The output from driver 108 is regulated by a voltage regulator circuit 114. A back EMF clamp diode 116 is interposed in the motor supply conductors. A connector 118a is adapted to be matched with connector 118b, FIG. 3B, to provide signals related to motor operation to and from a microcontroller, which, together with associated circuitry, will now be described.

Referring to FIGS. 3A and 3B, these figures are intended to be read together as one circuit diagram by matching the figures along the lines a--a. A key element of the main controller unit 64 is an eight bit programmable microcontroller 120, FIG. 3B, which may be of a type made by Microchip Corporation as their Model PIC16C72. The microcontroller 120 includes internal A/D converter circuits for all analog voltage signals input thereto and is driven by a five volt source, not shown, through a filter circuit 122. Microcontroller 120 is also connected, as shown, to a ten megahertz oscillator 124 operating as a clock for the microcontroller.

Output signals from the microcontroller 120 include an output at conductor 120a and current limiting resistors R27 and R29 to provide a switching signal through transistor 124 which provides a suitable relay voltage signal to energize relay actuator 76, FIG. 4, to turn on the operator light or lamp 59 and provide power to rectifier 86, FIG. 4. Motor direction of rotation control signals are imposed by microcontroller 120 on pin RC2 and conductor 120b, FIG. 3B, through current limiting resistors R28 and R30 and transistor 130 to control the motor directional control relay 78. An output signal imposed on conductor 120c is fed directly through current limiting resistor R32 to the pulse width modulation control circuit conductor 110, FIG. 4, for controlling the driver 108 to vary the voltage pulse width imposed on the motor 34.

The controller unit 64 may be controlled by a radio signal provided from radio receiver 66 which signal is imposed on a decoder circuit 132, FIG. 3B, which is operably connected to the microcontroller 120. The input signal from the radio receiver 66 is imposed on conductor 132a into the circuit 132. Input signals to the microcontroller 120 include signals proportional to the current flowing to the motor 34 in both the door opening or upmode and the door closing or downmode and including a signal conducted via conductor 134 from the connectors 118a and 118b and conductor 136, FIG. 4, providing the signal from the Hall effect sensor 100. As shown in FIG. 3B, this signal is imposed on a filter network 138. The filter network 138 is comprised of two sections, 138a and 138b. The response of section 138a is such that the filter holds the most positive peak voltage from the output of the Hall effect sensor 100, FIG. 4. The output signal of section 138a is provided to the microcontroller 120 by conductor 140. The response of section 138b is such as to hold the most negative peak voltage from the output of the Hall effect sensor 100, FIG. 4. The output signal of section 138b is provided to the microcontroller 120 by conductor 142. Voltage signals proportional to the current flowing through the motor 34 in the door opening operating mode and the door closing operating mode are thus imposed on the controller 120 via the conductors 140 and 142 and these voltage signals vary in relation to the current flowing through the motor which is proportional to motor load. Moreover, the signal output from Hall effect sensor 100 responds to the direction of current flow and the direction of magnetic flux produced in transformer 98. Accordingly, the Hall effect sensor signal output can be used to sense the direction of rotation of motor 34.

The microcontroller 120 is capable of commanding the motor 34 to stop if operating in the door opening mode or to stop and reverse if operating in the door closing mode if the signals to the microcontroller 120 by way of the conductors 140 and 142 exceed preset values. These values may be set by user settable potentiometer type control circuits as shown in FIG. 3A wherein a potentiometer 144 is user settable by a manually operable control knob 144a, FIGS. 1 and 1A. Current limiting resistors R39 and R42 are in circuit with the potentiometer 144 and a current limiting resistor R36 is in circuit with the conductor 150, FIGS. 3A and 3B. Accordingly, a variable voltage signal may be imposed on the pin RAO/ANO of microcontroller 120 which will preset the maximum motor current limit the microcontroller senses by way of the proportional voltage signal which is imposed on terminal RA3/AN3 via conductor 142.

The microcontroller 120 is operable, upon sensing a voltage signal via conductor 142 which exceeds that set by the potentiometer 144 to effect stopping the motor 34 and reversing the motor to cause a door connected to the operator 10 to move to an open position. Conversely, a user settable motor load control potentiometer 154 is in circuit with the microcontroller 120 via conductor 156 to pin RAI/ANI. Control knob 154a, FIGS. 1 and 1A, is connected to the potentiometer 154 for adjusting the position of same. Current limiting resistors R40 and R41 are in circuit with the potentiometer 154 and a current limiting resistor R35 is interposed in conductor 156 as shown. Accordingly, when the motor 34 is operating a door to move to an open position if the motor current should exceed that preset by the potentiometer 154 the microcontroller 120 will effect motor shutoff by failing to send an enabling signal to the driver 108. Control knobs 144a and 154a are preferably mounted directly on potentiometers 144 and 154 on controller unit 64 and are user accessible as shown in FIG. 1.

A user operated control unit 146, FIG. 3A, includes a momentary or push button type switch 146c which is operable to effect opening or closing movement of a door connected to the operator 10, depending on the condition of the operator and the position of the door. The so-called "command" or control unit 146 is normally mounted on a wall within the enclosure or garage, not shown, with which the operator 10 is associated. Still further, the control unit 146 includes suitable switches 146d and 146e which are operable, respectively, to "lock out" operation of the operator 10 and to manually operate the light 59 which illuminates the garage area in the vicinity of the operator. Circuit 160, FIG. 3A is a current source for the control unit 146. Analog input signals from the switches of control unit 146 are conducted to pin RA2/AN2 via conductor 162. Current limiting resistors R64 and JMP12 are interposed in the conductor 162 and transient voltage clamping diodes D5 and D6 are connected to conductor 162.

As further shown in FIG. 3A, the controller unit 64 is operable to receive a signal from a doorway obstruction detector 166, typically a pulse type signal, via resistors JMP30, R56 and R57 and transistor Q7 to input pin RB5 of microcontroller 120. A signal indicating whether or not obstruction detector 166 is operable may also be imposed on microcontroller 120 through a circuit including a transistor and associated resistors and diodes, not shown, and connected to pin RB7, if application requirements include such a feature. Door position "up" limit switch 25 is operable to impose a signal on the microcontroller at pin RB1 via conductive path 170. In like manner a signal from the door position down limit switch 23 is imposed on pin RB4 of microcontroller 120 via conductive path 172. Conductive paths 168, 170 and 172 are connected to suitable noise filtering and transient voltage clamp circuitry, as shown in FIG. 3A. Connector 157, through which signals from the control unit 146, the switches 23 and 25 and the obstruction detector 166 are transmitted, also includes a conductor port 174 for an external radio connection to also provide a suitable input signal to the microcontroller 120, if desired.

FIG. 3A also illustrates the circuit components for the photosensor encoder 56 whose pulse type signal is delivered to microcontroller 120 via conductive path 180 at pin RB0 of microcontroller 120. Pin RB3 of microcontroller 120 is connected to an LED 184 via a conductive path 186 for indicating system status during servicing operations. Microcontroller 120 is connected to decoder 132 via a conductive path 188 to reset the decoder for receiving successive signal inputs from the radio receiver 66. The circuit elements not specifically discussed hereinabove but shown on FIGS. 3A and 3B are believed to be readily understandable to those of ordinary skill in the art based on the foregoing description of the circuitry of the controller unit 64 and the motor control circuit 62.

Accordingly, the controller unit 64 and the motor control circuit 62 are operable to control operation of the motor 34 in response to commands from the control unit 146 or commands received from the receiver 66. The microcontroller 120 is adapted to be programmed to operate the motor 34 in the door opening mode at a predetermined speed for a sectional type door, for example, a linear speed of about b 14.0 inches per second. However, the speed of movement of the door in the closing mode is preferably somewhat less than the door opening speed, namely about 5.5 inches per second to 7.0 inches per second linear speed. Accordingly the door 21a may be opened quickly but is closed at a predetermined lower speed which will minimize any hazards to persons attempting to move through the doorway while the door is in motion toward the closed position.

The microcontroller 120 is also programmed to determine the type of door connected to the operator 10 during initial and any subsequent operation of the motor 34 to move the door from a closed position to an open position. Thanks to the provision of the pulse encoder 56, a pulse type signal related to linear travel of the operator drive mechanism and a door connected thereto is measured during each movement of the door from a closed limit position to an open limit position. If this travel distance, as measured by the encoder pulse count delivered to the microcontroller 120 from the encoder 56, indicates a linear travel of the operator of less than 4.0 feet, for example, the microcontroller automatically acknowledges that the type of door in which the operator is connected is a one piece or so-called California type door. If this shortened linear travel distance is detected, subsequent operations of the operator 10 will drive the door from a closed position to an open position at a reduced speed, preferably 5.5 inches per second to 7.0 inches per second, for example, which is preferable due to the rapid movement of the edge of a one piece door as compared to movement of a sectional type door. Accordingly, the operator 10 automatically adjusts the speed of travel of a door to accommodate the type of door to which the operator is connected.

Still further, the operator 10 may be set up so that the microcontroller 120 automatically shuts off motor 34 in the door opening or closing mode if a predetermined maximum motor load is encountered indicating an obstruction or a door limit position. The pulse width modulated voltage signal delivered to motor 34 may be preset to a maximum pulse width as a function of time for both the operator opening and closing operating modes. These maximum motor voltage pulse widths and motor load values may be, effectively, adjusted in the up and down operating modes by way of the potentiometers 144 and 154, respectively by the door user by adjusting the potentiometers at the control unit 146. The voltage signals imposed on the microcontroller 120 by way of the conductive paths 150 and 156, respectively, correspond to a maximum current value sensed by the current sensor circuit including the transformer 98 and the Hall effect sensor 100 and the associated circuitry connected thereto and described hereinabove. In operation, the microcontroller 120 automatically adjusts the pulse width of the voltage signal imposed on the motor 34 in accordance with the direction of travel and the type of door connected to the operator 10 to maintain the predetermined speeds mentioned above. These predetermined speeds are accomplished through the feedback signal provided by the photosensor encoder 56 and the associated wheel 52 mounted on the motor shaft 38.

Still further, the operating speed of the motor 34 when moving the door between open and closed positions may be controlled to accelerate movement of the door initially up to the limit speed and then, as a consequence of measuring the distance of movement of the door and comparing that distance to the total distance of movement between the limit switches 23 and 25 the microcontroller 120 may control the pulse width modulated signal delivered to the motor 34 to decelerate or slow down movement of the door just prior to actuation of the limit switches 23 or 25. In this way, the door connected to the operator 10 may be accelerated and decelerated smoothly, although actual shut off of current to the motor 34 is subject to actuation of the limit switches 23 or 25. Such operation substantially reduces stress and strain on the operator 10 and a door structure connected thereto.

Microcontroller 120 may also be programmed to effect operation of a door connected to operator 10 in an opening and/or closing mode at a maximum frequency of operating cycles. Still further, the microcontroller may be programmed to "lock out" the maximum motor load setting as set by the potentiometers 144 and 154 for predetermined periods of time during initial start up of the motor from a door open position or a closed position to overcome friction and inertia in the door and operator system and to allow a door to "break free" when moved from a closed position to an open position if, for example, there is an accumulation of ice or debris adjacent to the door which would resist door opening movement.

Referring now to FIG. 5, there is illustrated a so-called state diagram for the door operator 10 as controlled by the controller unit 64 and the motor control circuit 62. The numbered paths of the diagram of FIG. 5 refer to operating algorithms. After any previous operation of the operator 10, the controller unit 64 is reset automatically by clearing all timing functions, turning off the garage light or lamp 59 and initializing a memory circuit of the microcontroller 120. In this condition, the motor 34 is shut off and the door 21a may be in an open, partially opened or closed position.

If a signal is received by microcontroller 120 from receiver 66 or switch 146c, or an external radio source by way of conductive path 174, and the door position is such that up limit switch 25 is not closed and the lock switch 146d has not been actuated and current is not already flowing to the motor by way of the relays 78 and 82 and the controller 120 has not sensed an operating cycle frequency greater than a preset maximum (algorithm 1), the controller unit 64 will effect energization of the motor 34 to move a door toward the up or open position and lamp 59 will be turned on. The microcontroller 120 will sequence the operation of the circuit 62 by energizing the relay 78 during a period of forty microseconds followed by energization of the lamp 59 during a following period of 40 microseconds and then energizing the relay 92, 94 during a third forty microsecond period. During the first one second of operation of the motor 34 to move the door toward an up or open position, the driver 108 is controlled to accelerate the motor to the preset speed of 14 inches per second or 5.5 inches per second if a California type door has been connected to the operator 10. As the door approaches the switch 25, as detected by the number of counts or pulse signals delivered from the encoder 56 to the microcontroller, during a one second interval prior to engagement of the switch 25, motor 34 is decelerated to slow movement of the door to a speed of approximately three inches per second prior to actuation of switch 25. Actuation of switch 25, of course, stops operation of the motor 34 and resets the controller unit 64.

If the door is moving toward the up or open position and signals are received by the microcontroller 120 from switch 146c or receiver 66 or the external radio circuit or the switch 25 or the operating time of the motor is greater than a maximum cycle time (i.e., about 29 seconds) or the motor "torque" limit has been exceeded by a current sensed through the transformer 98 and Hall effect sensor 100, which is greater than the limit set by the potentiometer 154 and this signal is sensed at a time greater than about 0.5 seconds and relays 78, 82 are not in the wrong position (current flowing when relay is open) the motor 34 is shutoff and the controller unit 64 reset (algorithm 2).

Referring further to the diagram of FIG. 5, if the state of the operator 10 is in the stopped condition and the aforementioned pushbutton switch 146c, or a signal from radio receiver 66 or an external radio is received and switch 23 is not actuated (indicating the door in a down limit position), and the door is movable down or the switch 25 is actuated and detector 166 does not detect an obstruction and operating cycle frequency has not been exceeded and relays 78, 82 are not in the wrong position, motor 34 will be energized (algorithm 3) to move the door downward at a reduced speed again through the acceleration phase described above and the one second deceleration phase also described above which is initiated just prior to the magnet 26 moving into proximity to the switch 23. Movement toward the down position will continue unless the setting of potentiometer 144 as detected by the microcontroller 120 is exceeded by the current signal received from the sensor comprising the transformer 98 and Hall effect sensor 100 and the system has not exceeded the operating cycle frequency limit. When the down limit switch 23 is actuated the controller unit 64 will return to the stop state. However, if the down limit switch 23 is actuated or a signal is received by the microcontroller 120 from pushbutton switch 146c, receiver 66 or an external radio before the down limit switch is actuated, the controller unit 64 will stop operation of the motor 34 and reset the control circuitry for a further signal (algorithm 4). In all algorithms 1 through 11, the motor relays 78 and 82 must be in the proper position for the command given.

If the motor 34 is operating to move the door to the down limit position and has not actuated switch 23 and microcontroller 120 has received a signal from the obstruction detector 166, the pushbutton switch 146c or the receiver 66 or an external radio, or operating time has exceeded the maximum cycle time (twenty-nine seconds) or the setting of potentiometer 144 has been exceeded by motor current flow and this setting has not been overridden by the pushbutton switch 146c or by a timing signal of 0.5 seconds, the controller will cause the motor 34 to pause (algorithm 5). In the pause condition, if the operator 10 is at the door up limit position and the relays are in proper position, the operator 10 will move the door to the closed position, stop the motor 34 and reset the controller unit 64 (algorithm 6). In the pause condition, if the operator 10 is not at the door up limit position and the operating time is greater than 0.5 seconds from startup, the door will move to the open or up position (algorithm 7).

If the door 21a is not moving to the down position and a relay status signal indicates an incorrect motor relay position, an error state will occur and the operator will stop motor 34 (algorithm 8). Algorithms 9, 10 and 11 also create an error status if the motor relays 78 and/or 82 indicate motor current flow or direction not commanded. Controller unit 64 stops current flow to motor 34 at all error status conditions.

As further indicated by the state diagram of FIG. 5 (algorithm 19) if a signal has been received to effect operation of the operator 10, the lamp 59 will be energized to indicate that power is supplied to the operator 10, but the operator is otherwise inoperable. With regard to algorithm 20, unless the switch 146e has been actuated to manually turn on lamp 128, the lamp 128 will turn off after a predetermined interval, such as five minutes. Still further, as indicated by algorithm 21, if operating cycle frequency is greater than a predetermined frequency, the system will not operate until a predetermined time interval has elapsed.

The construction and operation of the operator 10, including the motor control circuit 62 and the controller unit 64, as well as a method of controlling operation of a door with the operator 10, is believed to be understandable to those of ordinary skill in the art of door operator systems based on the foregoing description. Conventional engineering materials and components may be used to carry out the invention, all of which are commercially available at the time of filing of the instant application. Although a preferred embodiment of the invention has been described in detail herein, sufficient to enable those skilled in the art to practice the invention, various substitutions and modifications may be made to the invention without departing from the scope and spirit of the appended claims.