Microprocessor-based control for trailer brakes
DC CAFCFirst Claim
1. A brake controller for controlling the brakes of a towed vehicle, said brake controller comprising:
- an input circuit for generating a brake level signal representing the braking force to be applied by the towed vehicle'"'"'s brakes;
a display circuit including a plurality of indicator lights;
a power switching circuit and adapted for coupling to the brakes of the towed vehicle and to the power supply of the towing vehicle, for selectively supplying power from the towing vehicle power supply to the brakes of the towed vehicle in response to a switching control signal supplied to a control input terminal;
a current sensing circuit for sensing a level of braking current supplied to the brakes of the towed vehicle through said power switching circuit, and for generating a current level signal representing the sensed level of braking current; and
a microcontroller coupled to said input circuit, said display circuit, said current circuit, and to said power switching circuit, said microcontroller generating and supplying a switching control signal to said control input terminal of said power switching circuit thereby causing said power switching circuit to deliver a braking current to the brakes of the towed vehicle that is related to the brake level signal supplied to said microcontroller by said input circuit, said microcontroller illuminating one or more of said indicator lights of said display circuit to indicate a relative level of braking of the towed vehicle brakes and controlling one or more of said indicator lights to indicate that the towed vehicle brakes are or are not properly connected to said power switching circuit.
19 Assignments
Litigations
2 Petitions
Accused Products
Abstract
An electronic brake controller for controlling the brakes of a towed vehicle in response to commands from the towing vehicle. The controller implements a microcontroller (10) that works in conjunction with analog circuit technology. In a preferred embodiment, the brake controller includes an input circuit (16) for generating a brake level signal representing the braking force to be applied by the towed vehicle'"'"'s brakes, a display circuit (22) including a plurality of indicator lights, a power switching circuit (24) adapted for coupling to the brakes of the towed vehicle and to the power supply of the towing vehicle, for selectively supplying power from the towing vehicle power supply to the brakes of the towed vehicle in response to a switching control signal supplied to a control input terminal, a current sensing circuit (26) for sensing a level of braking current supplied to the brakes of the towed vehicle through the power switching circuit (24), and for generating a current level signal representing the sensed level of braking current, and a microcontroller (10) for generating and supplying a switching control signal to the control input terminal of said power switching circuit (24) thereby causing the power switching circuit (24) to deliver a braking current to the brakes of the towed vehicle that is related to the brake level signal supplied to the microcontroller (10) by the input circuit (16), the microcontroller (10) illuminates one or more of the indicator lights of the display circuit (22) to indicate a relative level of braking of the towed vehicle brakes and controls one or more of the indicator lights to indicate that the towed vehicle brakes are or are not properly connected to the power switching circuit (24).
123 Citations
76 Claims
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1. A brake controller for controlling the brakes of a towed vehicle, said brake controller comprising:
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an input circuit for generating a brake level signal representing the braking force to be applied by the towed vehicle'"'"'s brakes; a display circuit including a plurality of indicator lights; a power switching circuit and adapted for coupling to the brakes of the towed vehicle and to the power supply of the towing vehicle, for selectively supplying power from the towing vehicle power supply to the brakes of the towed vehicle in response to a switching control signal supplied to a control input terminal; a current sensing circuit for sensing a level of braking current supplied to the brakes of the towed vehicle through said power switching circuit, and for generating a current level signal representing the sensed level of braking current; and a microcontroller coupled to said input circuit, said display circuit, said current circuit, and to said power switching circuit, said microcontroller generating and supplying a switching control signal to said control input terminal of said power switching circuit thereby causing said power switching circuit to deliver a braking current to the brakes of the towed vehicle that is related to the brake level signal supplied to said microcontroller by said input circuit, said microcontroller illuminating one or more of said indicator lights of said display circuit to indicate a relative level of braking of the towed vehicle brakes and controlling one or more of said indicator lights to indicate that the towed vehicle brakes are or are not properly connected to said power switching circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A brake controller for controlling the brakes of a towed vehicle, said brake controller comprising:
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an input circuit for generating a brake level signal representing the braking force to be applied by the towed vehicle'"'"'s brakes; a power switching circuit having a control input terminal and adapted for coupling to the brakes of the towed vehicle and to the power supply of the towing vehicle, for selectively supplying power from the towing vehicle power supply to the brakes of the towed vehicle in response to a switching control signal supplied to said control input terminal; and a microcontroller coupled to said input circuit and to said power switching circuit, said microcontroller being operable in a set-up mode and an operating mode, wherein, in said set-up mode, said microcontroller determines a number of axles of the towed vehicle and stores the number of axles, and in said operating mode, said microcontroller generates and supplies a switching control signal to said control input terminal of said power switching circuit thereby causing said power switching circuit to deliver a braking current to the brakes of the towed vehicle that is related to the brake level signal supplied to said microcontroller by said input circuit and that is adjusted by said microcontroller to account for the number of axles of the towed vehicle. - View Dependent Claims (14, 15, 16, 17)
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18. A brake controller for controlling the brakes of a towed vehicle, said brake controller comprising:
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an input circuit for generating a brake level signal representing the braking force to be applied by the towed vehicle'"'"'s brakes; a power switching circuit and adapted for coupling to the brakes of the towed vehicle and to the power supply of the towing vehicle, for selectively supplying power from the towing vehicle power supply to the brakes of the towed vehicle in response to a switching control signal supplied to a control input terminal; and a display circuit for receiving display signals and for displaying information to the operator in response to said display signals that represents the relative braking force applied to the towed vehicle brakes; a microcontroller coupled to said input circuit, to said display circuit, and to said power switching circuit, said microcontroller being operable in a set-up mode and an operating mode, wherein, in said set-up mode, said microcontroller determines a number of axles of the towed vehicle and stores the number of axles, and in said operating mode, said microcontroller generates and supplies a switching control signal to said control input terminal of said power switching circuit thereby causing said power switching circuit to deliver a braking current to the brakes of the towed vehicle that is related to the brake level signal supplied to said microcontroller by said input circuit, wherein said microcontroller scales the display signals that are supplied to said display circuit based upon the input number of axles of the towed vehicle.
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19. A brake controller for controlling the brakes of a towed vehicle, said brake controller comprising:
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an input circuit for generating a brake level signal representing the braking force to be applied by the towed vehicle'"'"'s brakes; a power switching circuit and adapted for coupling to the brakes of the towed vehicle and to the power supply of the towing vehicle, for selectively supplying power from the towing vehicle power supply to the brakes of the towed vehicle in response to a switching control signal supplied to a control input terminal; a microcontroller coupled to said input circuit and to said power switching circuit, said microcontroller generating and supplying a switching control signal to said control input terminal of said power switching circuit thereby causing said power switching circuit to deliver a braking current to the brakes of the towed vehicle that is related to the brake level signal supplied to said microcontroller by said input circuit; and malfunction monitoring means for monitoring the functioning of said microcontroller and resetting said microcontroller when a malfunction is detected. - View Dependent Claims (20)
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21. A brake controller for controlling the brakes of a towed vehicle, said brake controller comprising:
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a sensor input circuit including a decelerometer for sensing the deceleration of the towing vehicle and for generating a brake level signal representing the desired braking when the brakes of the towing vehicle are actuated and the sensed deceleration exceeds a threshold level, said sensor input circuit including means for adjusting the threshold level of said decelerometer; a display circuit including an indicator light; a power switching circuit having a control input terminal and adapted for coupling to the brakes of the towed vehicle and to the power supply of the towing vehicle, for selectively supplying power from the towing vehicle power supply to the brakes of the towed vehicle in response to a switching control signal supplied to said control input terminal; and a microcontroller coupled to said sensor input circuit, said display circuit, and to said power switching circuit, said microcontroller generating and supplying said switching control signal to said control input terminal of said power switching circuit thereby causing said power switching circuit to deliver a braking current to the brakes of the towed vehicle that is related to the brake level signal supplied to said microcontroller by said sensor input circuit, said microcontroller illuminating said indicator light of said display circuit when said microcontroller receives a brake level control signal from said sensor input circuit. - View Dependent Claims (22, 23, 24, 25, 26)
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27. In an electronic brake control system having a power switching circuit for selectively supplying braking current to the towed vehicle brakes in response to a control signal, a method comprising the steps of:
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determining whether the brakes of the towed vehicle are to be activated; periodically generating and supplying a control signal to the power switching circuit to supply a level of braking current that is too low to cause noticeable braking of the towed vehicle when it is determined that the brakes of the towed vehicle are not to be activated; sensing the braking current flowing through said power switching circuit when the control signal is periodically generated; determining whether the braking system is operating abnormally based upon the sensed level of braking current; and generating a warning signal to warn an operator of the towing vehicle of abnormal operation when the sensed braking current is not at an expected current level. - View Dependent Claims (28, 29, 30, 31, 32, 33)
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34. In an electronic brake control system having a power switching circuit for selectively supplying braking current to the towed vehicle brakes in response to a pulse width modulated control signal having a variable duty cycle, a method comprising the steps of:
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applying a pulse width modulated control signal to the power switching circuit; sensing the braking current flowing through the power switching circuit; determining that a short circuit or current overload condition exists in the brakes of the towed vehicle when the sensed braking current exceeds a threshold current level; and changing the duty cycle and the frequency of the pulse width modulated control signal applied to the power switching circuit to selectively reduce the supplied braking current when a short circuit or current overload condition is found to exist. - View Dependent Claims (35, 36, 37, 38, 39, 40)
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41. A brake controller for controlling the brakes of a towed vehicle, said brake controller comprising:
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an input circuit for generating a brake level signal representing the braking force to be applied by the towed vehicle'"'"'s brakes; a display circuit including a plurality of indicator lights; a power switching circuit adapted for coupling to the brakes of the towed vehicle and to the power supply of the towing vehicle, for selectively supplying power from the towing vehicle power supply to the brakes of the towed vehicle in response to a switching control signal supplied to a control input terminal; a microcontroller coupled to said input circuit, to said display circuit, and to said power switching circuit, said microcontroller in an operating mode generating and supplying a switching control signal to said control input terminal of said power switching circuit thereby causing said power switching circuit to deliver a braking current to the brakes of the towed vehicle that is related to the brake level signal supplied to said microcontroller by said input circuit while illuminating one or more of said indicator lights to indicate a relative level of towed vehicle braking, and said microcontroller in a self-testing mode gradually and continuously varying the level of the switching control signal while inhibiting power from being supplied through said power switching circuit and illuminating one or more of said indicator lights to reflect the changing levels of the switching control signal. - View Dependent Claims (42, 43)
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44. A brake controller for controlling the brakes of a towed vehicle, said brake controller comprising:
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a brake light circuit adapted for coupling to a brake light of a towing vehicle for generating an output signal when the brake light is illuminated as a basis for determining that the brakes of the towing vehicle are actuated; a sensor input circuit coupled to said brake light circuit for sensing the deceleration of the towing vehicle in response to said output signal from said brake light circuit; a manual input circuit for receiving input from an operator of the towing vehicle of a desired braking force of the towed vehicle'"'"'s brakes; a gain adjustment circuit coupled to said manual input circuit and to said sensor input circuit for receiving brake level signals output therefrom that are indicative of a desired level of braking and for generating a gain-adjusted brake level signal in response to a brake level signal received from either said manual input circuit or said sensor input circuit; a power control circuit adapted for coupling to a power supply of the towing vehicle for supplying power to the brakes of the towed vehicle; a power switching circuit coupled to said power control circuit and having a brake terminal adapted for coupling to the brakes of the towed vehicle, for selectively supplying power from said power control circuit to the brakes of the towed vehicle in response to a switching control signal supplied to a control input terminal; a current sensing circuit for sensing a level of braking current supplied from said power control circuit to the brakes of the towed vehicle through said power switching circuit, and for generating a current level signal representing the sensed level of braking current; a display circuit for displaying information to the operator of the towing vehicle; a microcontroller coupled to said brake light circuit, said sensor input circuit, said manual input circuit, said gain adjustment circuit, said power control circuit, said power switching circuit, said current sensing circuit, and to said display circuit, said microcontroller adapted to generate and supply a switching control signal to said control input terminal of said power switching circuit thereby causing said power switching circuit to deliver a braking current to the brakes of the towed vehicle that is related to the gain-adjusted brake level signal supplied to said microcontroller by said gain adjusting circuit. - View Dependent Claims (45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60)
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61. In an electronic brake control system having a power switching circuit for selectively supplying braking current to the towed vehicle brakes in response to a control signal, a method comprising the steps of:
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determining whether the brakes of the towed vehicle are to be activated; periodically generating and supplying a first control signal to the power switching circuit to supply a level of braking current that is too low to cause noticeable braking of the towed vehicle when it is determined that the brakes of the towed vehicle are not to be activated; identifying and storing a baseline braking current flowing through the power switching circuit when the first control signal is periodically generated; generating and supplying a second control signal to the power switching circuit when it is determined that the brakes of the towed vehicle are to be activated, said second control signal having a level corresponding to the desired level of braking; sensing the braking current supplied to the towed vehicle brakes by the power switching circuit in response to the second control signal; and displaying an indication of the magnitude of braking current supplied to the towed vehicle brakes by generating a display corresponding to the difference between the magnitudes of the baseline braking current and the sensed braking current. - View Dependent Claims (62)
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63. In an electronic brake control system having a power switching circuit for selectively supplying braking current to the towed vehicle brakes in response to a control signal, a method comprising the steps of:
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determining whether the brakes of the towed vehicle are to be activated; periodically generating and supplying a control signal to the power switching circuit to supply a level of braking current that is too low to cause noticeable braking of the towed vehicle when it is determined that the brakes of the towed vehicle are not to be activated; sensing the braking current flowing through said power switching circuit when the control signal is periodically generated; determining whether the braking system is operating abnormally based upon the sensed level of braking current; and generating a signal to advise an operator of the towing vehicle that the towed vehicle'"'"'s brakes are connected properly unless an abnormal operation is detected.
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64. A brake controller for controlling the brakes of a towed vehicle, said brake controller comprising:
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an input circuit for generating a brake level signal representing the braking force to be applied by the towed vehicle'"'"'s brakes; a power switching circuit adapted for coupling to the brakes of the towed vehicle and to the power supply of the towing vehicle, for selectively supplying power from the towing vehicle power supply to the brakes of the towed vehicle in response to a pulse width modulated control signal supplied to a control input terminal whereby the braking current supplied to the towed vehicle brakes corresponds to a duty cycle of the pulse width modulated control signal; and a microcontroller coupled to said input circuit and to said power switching circuit, said microcontroller generating and supplying the pulse width modulated control signal to said control input terminal of said power switching circuit, said microcontroller varying the duty cycle of the pulse width modulated control signal in response to the brake level signal supplied to said microcontroller by said input circuit to thereby cause said power switching circuit to deliver a braking current to the brakes of the towed vehicle that corresponds to the desired level of braking. - View Dependent Claims (65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76)
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Specification