Vehicle power window control

• US 4,562,387 A
• Filed: 11/26/1984
• Issued: 12/31/1985
• Est. Priority Date: 11/26/1984
• Status: Expired due to Fees

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Lehnhoff, Richard N.
• Primary Examiner(s): Dobeck, B.
• Assistant Examiner(s): Ro, Bentsu
• Application Number:
  US06/674,689
• Time in Patent Office: 400 Days
• Field of Search: 318/280, 318/281, 318/282, 318/286, 318/293, 318/294, 318/345 B, 318/345 C, 318/265, 318/266, 318/267, 318/285, 318/466, 318/469
• US Class Current: 318/285
• CPC Class Codes: E05F 15/41 Detection by monitoring transmitted force or torque E05F15/48 takes precedence; Safety couplings with activation dependent upon torque or force, e.g. slip couplings
• CPC Class Codes: E05F 15/695 Control circuits therefor
• CPC Class Codes: E05Y 2900/55 Windows
• CPC Class Codes: H02H 7/0838 with H-bridge circuit
• CPC Class Codes: H02H 7/0851 for motors actuating a movable member between two end positions, e.g. detecting an end position or obstruction by overload signal
• CPC Class Codes: H02P 7/04 by means of a H-bridge circuit

Abstract

A control for a vehicle window driving motor in an H-switch semiconductor bridge with an SCR and a FET in each opposite armature current path includes control logic circuitry enabling one-touch actuation of window movement in either direction with stoppage by actuating either actuation device and with flip-flop control of the bridge elements to prevent shorting out the power supply. A variation provides automatic stoppage in the up direction by stall current sensing with automatic reverse after a time delay to allow the SCR conducting during upward movement to turn off.

Claims

1. Window motor control apparatus for a vehicle window capable of movement between stopped open and closed positions comprising, in combination:

a motor drive circuit effective to drive the window motor selectively toward the open or closed position of the window, said motor drive circuit comprising a DC motor having an armature connected in an H-switch bridge across an electrical power supply with a first SCR and first FET actuable to conduct armature current in one direction and a second SCR and second FET actuable to conduct armature current in the opposite direction;

first and second actuating means;

a toggle flip-flop having toggle and reset inputs and an output deactivated when the reset input is activated;

an OR logic circuit connecting the first and second actuating means to the toggle input of the toggle flip-flop;

a second flip-flop having a set input responsive to the first actuating means and a reset input responsive to the second actuating means and a pair of outputs, each of the outputs activated in a different one of two stable states;

a first AND logic circuit having inputs from the output of the toggle flip-flop and one of the outputs of the second flip-flop and an output connected to activate the motor drive circuit toward the open position of the window;

a second AND logic circuit having inputs from the output of the toggle flip-flop and the other of the outputs of the second flip-flop and an output connected to activate the motor drive circuit toward the closed position of the window; and

means effective to detect stall current in the DC motor armature with the window in the stopped open or closed positions or due to an obstruction to window travel and activate the reset input of the toggle flip-flop, whereby the power supply is protected by the second flip-flop against a direct short circuit through an SCR and a FET in the H-switch bridge.

2. Window motor control apparatus for a motor vehicle window capable of movement between stopped open and closed positions comprising, in combination:

a motor drive circuit effective to drive the window motor selectively toward the open or closed position of the window, said motor drive circuit comprising a DC motor having an armature connected in an H-switch bridge across an electrical power supply with a first SCR and first FET actuable to conduct armature current in one direction and a second SCR and second FET actuable to conduct armature current in the opposite direction;

first and second actuating means;

a toggle flip-flop having toggle and reset inputs and an output deactivated when the reset input is activated;

an OR logic circuit connecting the first and second actuating means to the toggle input of the toggle flip-flop;

a second flip-flop having a set input responsive to the first actuating means and a reset input responsive to the second actuating means and a pair of outputs, each of the outputs activated in a different one of two stable states;

a first AND logic circuit having inputs from the output of the toggle flip-flop and one of the outputs of the second flip-flop and an output connected to activate the motor drive circuit toward the open position of the window;

a second AND logic circuit having inputs from the output of the toggle flip-flop and the other of the outputs of the second flip-flop and an output connected to activate the motor drive circuit toward the closed position of the window;

means effective to detect stall current in the DC motor armature with the window in the stopped open or closed positions or due to an obstruction to window travel and activate the reset input of the toggle flip-flop;

a timer;

means effective, while the window is moving toward, but has not yet reached, its closed position, to modify the operation of the stall current detecting means such that, upon detection of stall current, it also activates the timer; and

means responsive to a predetermined period of the timer to activate one of the actuating means to initiate window movement toward the closed position, whereby the power supply is protected by the second flip-flop and the timer against a direct short circuit through an SCR and a FET in the H-switch bridge.

3. Window motor control apparatus for a motor vehicle window capable of movement between stopped open and closed positions comprising, in combination:

a motor drive circuit effective to drive the window motor selectively toward the open or closed position of the window, said motor drive circuit comprising a DC motor having an armature connected in an H-switch bridge across an electrical power supply with a first SCR and first FET actuable to conduct armature current in one direction and a second SCR and second FET actuable to conduct armature current in the opposite direction;

first actuating means including a first AND logic circuit having one input from manual actuation means and another input;

second actuating means including a first OR logic circuit having one input from manual actuation means and another input;

a toggle flip-flop having toggle and reset inputs and an output deactivated when the reset input is activated;

a second OR logic circuit connecting the first and second actuating means to the toggle input of the toggle flip-flop;

a second flip-flop having a set input responsive to the first actuating means and a reset input responsive to the second actuating means and a pair of outputs, each of the outputs activated in a different one of two stable states;

a second AND logic circuit having inputs from the output of the toggle flip-flop and the output of the second flip-flop activated by the first actuation means and further having an output connected to activate the motor drive circuit toward the open position;

a third AND logic circuit having inputs from the output of the toggle flip-flop and the output of the second flip-flop activated by the second actuation means and further having an output connected to activate the motor drive circuit toward the closed position;

a third flip-flop having a clock input, a first output connected to the other input of the first AND logic circuit and a second output connected to the other input of the first OR logic circuit;

means effective to sense stall current in the DC motor armature;

RC timer apparatus effective to generate a clock signal a predetermined time after actuation, the clock signal being applied to the clock input of the third flip-flop;

comparator means effective to compare the stall current sensed by said last means with a reference and, when it exceeds the reference, actuate the reset input of the toggle flip-flop and the timer; and

means effective, when the window is being driven toward, but has not yet reached, the closed position, to provide a clock enabling signal to the third flip-flop and otherwise to provide a clock inhibiting signal to the third flip-flop, whereby the power supply is protected by the second and third flip-flops and the timer against a direct short circuit through an SCR and a FET in the H-switch bridge.

4. Apparatus according to claim 3 wherein said means to provide clock enabling and disabling signals includes a limit switch actuated in the closed position of the window, said apparatus further comprising:

a series resistor voltage divider across an electrical voltage source effective to generate the reference voltage for the comparator means; and

a series transistor switch and additional resistor connected in parallel with one of the resistors of said voltage divider, the conduction of the transistor switch being controlled by the limit switch to vary the reference voltage.

5. Apparatus according to claim 3 wherein:

the comparator switches from a first state to a second state when the stall current exceeds the reference and switches from the second state to the first state when the stall current falls below the reference again;

the RC timer apparatus comprises a capacitor adapted to be charged from an electrical current source through a diode when the comparator switches to its second state and to discharge through a resistor when the comparator switches back to its first state;

the RC timer further comprises inverter means effective to generate a rising edge clock signal when the capacitor voltage has fallen from its charged voltage back to a predetermined lower voltage; and

the third flip-flop responds only to a rising edge clock signal.