Brake system and current detection thereof

Abstract

The invention provides a brake system and current detection thereof. A brake system includes drive circuitry configured to transmit a brake signal from a towed vehicle to a towed vehicle connected to the towed vehicle; an output node configured to carry the brake signal; and a switch electrically between the drive circuitry and the output node. A current detector is in series with the switch and is configured to detect a current through the drive circuitry. The switch is configured to electrically connect and disconnect the drive circuitry from the output node in response to the current.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to a braking system and current detection thereof, and in particular to a circuit for detecting a condition of a trailer disconnect battery in a reverse condition. BACKGROUND

[0002] Consumers often compare available features and functionality between vehicles when making a purchase decision. Accordingly, additional solutions are needed to provide features and functionality that consumers desire. SUMMARY

[0003] According to a first aspect of the present disclosure, a braking system comprises: drive circuitry configured to transmit a brake signal from a towing vehicle to a towed vehicle connected to the towing vehicle; an output node configured to carry the brake signal; and a switch electrically interposed between the drive circuitry and the output node. A current detector is in series with the switch and is configured to detect a current through the drive circuitry. The switch is configured to electrically connect and electrically disconnect the drive circuitry from the output node in response to the current.

[0004] Embodiments of the first aspect of the present disclosure can include any one or combination of the following features:

[0005] - the output node is configured to be electrically coupled with a power source on the towed vehicle, the power source having a positive terminal and a negative terminal;

[0006] - in response to the output node being coupled with the negative terminal, the current detector detects a current flowing through the drive circuitry;

[0007] - the current detector comprises: a shunt in series with the switch; and at least one current sense amplifier having a programmable gain and configured to output a voltage representative of a current through the shunt;

[0008] - a comparator configured to control the switch in response to the voltage representative of the current flowing through the drive circuitry;

[0009] - the comparator is configured to disable the switch in response to the current flowing through the drive circuitry and a state of the drive circuitry;

[0010] - a latch circuit configured to keep the switch disabled after the switch is disabled;

[0011] - a controller in electrical communication with the current detector and configured to selectively release the latch circuit;

[0012] - a user interface configured to present an indication of a reverse battery condition of the towed vehicle in response to detecting the current when the drive circuit is powered off; and

[0013] - the output node is electrically coupled with at least one brake of the towed vehicle, the at least one brake configured to actuate in response to the brake signal.

[0014] According to a second aspect of the disclosure, a brake system comprises: drive circuitry configured to communicate a brake signal from a towing vehicle to a towed vehicle connected to the towing vehicle; an output node configured to carry the brake signal; and a switch electrically interposed between the drive circuitry and the output node. A current detector is in series with the switch and configured to detect a current through the drive circuitry and flowing to the switch. The switch is configured to electrically connect and electrically disconnect the drive circuitry from the output node in response to the current.

[0015] Embodiments of the second aspect of the disclosure can include any one or combination of the following features:

[0016] - the output node is configured to be electrically coupled with a power source on the towed vehicle, the power source having a positive terminal and a negative terminal, wherein the current detector detects a current flowing through the drive circuitry in response to the output node being coupled with the negative terminal;

[0017] - a shunt in series with the switch; and at least one current sense amplifier configured to output a voltage representative of a current through the shunt;

[0018] - a comparator configured to control the switch in response to the voltage representative of the current flowing through the drive circuitry;

[0019] - the comparator is configured to disable the switch in response to the current flowing through the drive circuitry;

[0020] - a latch circuit configured to maintain the switch disabled after the switch is disabled;

[0021] - a controller in electrical communication with the current detector and configured to selectively release the latch circuit;

[0022] - a user interface configured to present an indication of a reverse battery condition of the towed vehicle in response to detecting the current flowing through the drive circuitry; and

[0023] - the output node is electrically coupled with at least one brake of the towed vehicle, the at least one brake being configured to actuate in response to the brake signal.

[0024] According to a third aspect of the disclosure, a braking system comprises drive circuitry configured to communicate a brake signal from a towing vehicle to a towed vehicle connected to the towing vehicle, an output node configured to carry the brake signal, and a switch electrically interposed between the drive circuitry and the output node. A current detector is in series with the switch and is configured to detect a current through the drive circuitry. The switch is configured to electrically connect and electrically disconnect the drive circuitry with the output node in response to the current. A shunt is in series with the switch. At least one current sense amplifier is configured to output a voltage representative of a current through the shunt. A comparator is configured to control the switch in response to the voltage representative of the current flowing through the drive circuitry.

[0025] These and other features, advantages, and objects of the present disclosure will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0026] In the drawings:

[0027] Figure 1 is a perspective view of a towing arrangement between a towing vehicle and a towed vehicle, wherein the towed vehicle incorporates a braking system controlling braking of the towed vehicle;

[0028] Figure 2 is a functional block diagram of a braking system for controlling braking of a towed vehicle;

[0029] Figure 3 is an electrical schematic of a braking system incorporating reverse battery detection for a towed vehicle according to one aspect of the disclosure; and

[0030] Figure 4 is a process flow diagram of a method for detecting and indicating a reverse battery of a towed vehicle. DETAILED DESCRIPTION

[0031] Reference will now be made in detail to the preferred embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. In the drawings, the depicted structural elements are not drawn to scale and, for purposes of emphasis and understanding, certain components are exaggerated relative to others.

[0032] Detailed embodiments of the present disclosure are disclosed herein; however, it is understood that the disclosed embodiments are merely examples of the present disclosure, which can be embodied in various and alternative forms. The Figures do not necessarily reflect the precise design and could be simplified or minimized to illustrate the functional overview. Accordingly, the specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to employ the present disclosure in a different way.

[0033] For the purposes of description herein, the terms "upper", "lower", "right", "left", "rear", "front", "vertical", "horizontal", and derivatives thereof shall relate to the concepts as oriented in the drawing Figure 1 However, it is to be understood that the concepts can assume various alternative orientations, unless specifically indicated as being limited to a particular orientation. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.

[0034] The embodiments shown herein exist primarily in combinations of method steps and apparatus components related to a braking system and current detection thereof. Thus, the apparatus components and method steps have been represented, where appropriate, by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Moreover, the same reference numerals are used in different instances of similar elements throughout the specification.

[0035] Reference is made generally to Figures 1 to 4, trailer brake management system (TBMS 10) or brake system 10 is generally indicated at 10. Generally, when a trailer battery is reversed, TBMS 10 can utilize a hardware implementation to limit inoperability of drive circuitry in the event of a customer testing trailer operability. Thus, the present solution can limit overcurrent conditions of TBMS 10. TBMS 10 can also provide increased reaction time to limit overcurrent conditions by implementing a response detection mechanism that can be relatively simple to implement. TBMS 10 also provides enhanced user interaction by providing notification of a condition of TBMS 10 in response to an overcurrent condition or another condition of the circuit. TBMS 10 can also provide enhanced detection by not being limited to a harness resistance when a reversed battery condition occurs.

[0036] With continued reference to Figures 1 to 4 , TBMS 10 includes drive circuitry 11 configured to communicate a brake signal from a towing vehicle 12 to a towed vehicle 14 connected to towing vehicle 12. An output node 16 is configured to carry the brake signal. A switch 18 is electrically interposed between drive circuitry 11 and output node 16. A current detector 20 is in series with switch 18 and is configured to detect current through drive circuitry 11. Switch 18 is configured to electrically connect and disconnect drive circuitry 11 from output node 16 in response to the current.

[0037] Reference is now made to Figure 1 TBMS 10 can be controlled via towing vehicle 12. As illustrated, towed vehicle 14 can be operatively coupled with towing vehicle 12 such that operation of towing vehicle 12 (e.g., steering, braking, motion) can affect movement of towed vehicle 14. In the present example, towed vehicle 14 is a trailer, but it is contemplated that towed vehicle 14 can be any towed vehicle 14 that can include a power source 22 Figure 2 and Figure 3 TBMS 10 can be configured to communicate a signal to towed vehicle 14 in response to a brake signal communicated via a brake system of towing vehicle 12. Thus, TBMS 10 can be a distributed module, such as a rear zone module of towing vehicle 12, which can be configured to control various aspects related to a rear portion of the vehicle, such as a backup camera, proximity sensors, door sensors, rear lights, etc. As will be described in detail herein, TBMS 10 can include circuitry that communicates a brake signal to towed vehicle 14 in response to a brake signal from a brake system of the vehicle.

[0038] As shown, the towing vehicle 12 can include one or more brakes 24 for controlling the braking of the towed vehicle 14, which can be actuated in response to receiving an electrical signal. It is contemplated that the brakes 24 of the towed vehicle 14 can be electromagnetic brakes 24 or electro-pneumatic or hydraulic (EOH) brakes 24, or any other brakes 24 that can be actuated in response to an electrical signal from the towing vehicle. Thus, electro-pneumatic or EOH brakes are merely examples of types of brakes 24 that can be incorporated into the towed vehicle 14.

[0039] Referring now to Figure 2 The drive circuitry 11 can include drive circuitry that manages a target voltage or current and supplies the target voltage or current to electrical components of the towed vehicle 14. The drive circuitry 11 can include power modulators, sensing units, and / or filtering circuitry to provide a controlled modulated or constant signal to electrical components of the towed vehicle 14. The drive circuitry 11 can also or instead be configured to charge a power source 22 of the towed vehicle 14, such as a battery. The power source 22 can include any number of electrochemical cells and / or any type of power source 22, such as a lithium-ion battery, a lead-acid battery, or any other battery. In some examples, the power source 22 can be charged by the drive circuitry 11 or another electrical connection 28 with the towed vehicle 14.

[0040] The drive circuitry 11 can incorporate electrical components, such as high-power transistors or other drive circuitry. For example, the drive circuitry 11 can incorporate circuitry that generates a pulse-width modulated (PWM) signal to the brakes 24 of the towed vehicle 14. The drive circuitry 11 is configured to control the timing of the pulses to control the frequency of the signal to the brakes 24. In response, the brakes 24 can be configured to actuate at certain rates or braking levels based on the perceived frequency of the braking signal. The current detector 20 is in series with the switch 18 for measuring the current between the drive circuitry 11 and electrical components of the towed vehicle 14, such as the power source 22 and the brakes 24.

[0041] The switch 18 is disposed in series with the current detector 20 for interrupting or controlling the electrical connection 28 between the drive circuitry 11 and components of the towed vehicle 14. As will be further described with reference to Figure 3 The switch 18 can include any number of switching devices, such as transistors, relays, contactors, or any other electrical switching device. In some examples, the switch 18 is a high-speed switch 18, such as a metal-oxide-semiconductor field-effect transistor (MOSFET), which can be electrically activated or deactivated according to a signal to the gate of the MOSFET.

[0042] When the towed vehicle 14 is electrically coupled with the towing vehicle 12, components of the towed vehicle 14, such as the brakes 24 and the power source 22, are electrically coupled to the switch 18. For example, a wiring harness 26 can be provided on the towed vehicle / device 14 for connection with the towing device vehicle to provide electrical interconnection between the towing vehicle 12 and the towed vehicle 14. For example, at least one electrical connection 28 (e.g., connector, plug) can be provided between the towing vehicle 12 and the towed vehicle 14 Figure 3 ) to establish electrical communication therebetween. The signals exchanged can include turn signal signals, brake signals, power source signals, neutral signals, ground, and / or any other electrical signals. For example, a seven-pin connector, a four-pin connector, a 13-pin connector, or any other type of connector can be provided between the towing vehicle 12 and the towed vehicle 14. It is contemplated that the wiring harness 26 employed can provide electrical resistance. Accordingly, shunt voltage detection for overcurrent conditions can be limited to a certain detection range. Accordingly, the series arrangement provided herein can provide a greater range of protection.

[0043] With continued reference to Figure 2 A controller 30, which can incorporate a processor and at least one memory, can be in electrical communication with the drive circuitry 11, the current detector 20, and the switch 18 for controlling the drive circuitry 11, the current detector 20, and / or the switch 18. The controller 30 can also or instead receive data from the drive circuitry 11, the current detector 20, and / or the switch 18 related to the condition of the TBMS 10. For example, the memory of the controller 30 can store instructions that, when executed by the processor, cause the controller 30 to transmit or read one or more signals to or from the drive circuitry 11, the current detector 20, and / or the switch 18. For example, in operation, the controller 30 can transmit a control signal to the drive circuitry 11 to cause the drive circuitry 11 to transmit a brake signal or a charging signal to components of the towed vehicle 14. The controller 30 can also monitor the current detector 20 to detect overcurrent or atypical current conditions and / or any voltage or current related to the signals transmitted between the drive circuitry 11 and the components of the towed vehicle 14 via the output node 16. The controller 30 can then be configured to control the switch 18 in response to the current between the drive circuitry 11 and the current through the switch 18.

[0044] As will be referenced Figure 3In further detail, the current detector 20 can include control features such that control of the switch 18 can be based on signals from the current detector 20. In these examples, the controller 30 can not serve as an intermediary between the current detection and the switch 18. For example, in an overcurrent condition, the current detector 20 can directly communicate a signal to the switch 18 to open or shut off communication between components of the tow vehicle 14 and the drive circuitry 11. In other examples, the controller 30 processes signals from the current detector 20 and, in response to an overcurrent condition detected by the current detector 20, the controller 30 can communicate a signal to deactivate the switch 18. In other examples, the controller 30 can control other aspects (e.g., latching) related to the current detector 20 to control opening or closing of the switch 18.

[0045] With continued reference to Figure 2 , the controller 30 can communicate with other communication devices on a control area network (CAN 32) or other communication network to allow the controller 30 to communicate with other systems of the tow vehicle 12. For example, a user interface can be provided on the CAN 32 for presenting information related to the status of the TBMS 10. By way of example, information can be presented at the user interface regarding an overcurrent condition, a negative current condition, or any other current or power related condition of the TBMS 10. It is also contemplated that the controller 30 can communicate with other controllers 36 on the CAN 32, such as a master brake controller for the tow vehicle 12. Thus, while shown as a single controller 30 in the present example, it is contemplated that the single controller can be omitted or replaced by a master brake controller for the tow vehicle 12. In the present example, the controller 30 is part of a rear region module for the tow vehicle 12.

[0046] Reference is now made to Figure 3 , a more detailed schematic of the TBMS 10 is shown. The TBMS 10 can include an upstream switch 17 (e.g., MOSFET and / or diode) that limits current flow from the drive circuitry 11 to the power source. For example, in a reverse battery condition where the vehicle 12 is on and the trailer 14 is connected, when the disconnect switch 54 is pulled, the reverse current is limited from flowing back through the upstream switch 17.

[0047] With continued reference to Figure 3The drive circuitry 11 can include a high-side drive circuit 38 and a low-side drive circuit 40 each controlled by processing circuitry within or separate from the drive circuitry 11 to generate PWM signals (e.g., a modulation unit). The drive circuitry 11 can include a dedicated driver 41 configured to activate the high-side drive circuit 38 and the low-side drive circuit 40. For example, the driver 41 can be configured to drive the gate of a transistor in each of the drive circuits 38, 40. The high-side drive circuit 38 can be configured to activate when the low-side drive circuit 40 is deactivated, and vice versa. Activation of the drive circuits 38, 40 can operate in a synchronous switching mode with dead-time control to minimize power dissipation of the low-side drive circuit 40 during recirculation. By controlling the high-side drive circuit 38 and the low-side drive circuit 40, PWM signals can be communicated to the current detector 20 via the first node 42. Each of the high-side drive circuit 38 and the low-side drive circuit 40 can include a transistor, such as a MOSFET. Each drive circuit 38, 40 can include a body diode. For example, the low-side drive circuit 40 can include a body diode in parallel with the transistor, with the diode biased from a ground node toward the first node. The high-side drive circuit 38 can include a body diode biased from the first node 42 toward a power input of the drive circuitry 11.

[0048] The second node 44 is interposed between the current detector 20 and the switch 18. The output node 16 is interposed between the switch 18 and a component of the towed vehicle 14. Thus, in standard operation, a brake signal can be communicated from the drive circuitry 11 to a component of the towed vehicle 14 (e.g., the brake 24) via the first node 42, the second node 44, and the output node 16. When an overcurrent or non-standard current condition (e.g., a large positive (or negative) current) is detected via the current detector 20, the switch 18 (or 37) can be opened to limit electrical communication between the output node 16 and the first and second nodes 44 (or the power input). Although the current detector 20 is shown as being electrically interposed between the drive circuitry 11 and the switch 18, it is contemplated that the current detector 20 or another current sensing device can be electrically interposed between the switch 18 and a component of the towed vehicle 14.

[0049] In operation, the drive circuitry 11 controls the high-side drive circuit 38 and the low-side drive circuit 40 to provide a PWM signal (e.g., a brake signal). The PWM signal is generated by selectively connecting the first node 42 with power to the drive circuitry 11 by activating the high-side circuit and connecting the first node 42 to a neutral or ground via the activation of the low-side drive circuit 40. The activation pattern between the high-side drive circuit 38 and the low-side drive circuit 40 can generate that particular duty cycle / frequency of the brake signal communicated to the brake 24 via the switch 18. For example, light braking can correspond to a lower duty cycle of the PWM signal, while a strong brake signal can result in a higher duty cycle PWM signal communicated to the brake 24. In this way, the drive circuitry 11 can react to signals from the controller 30 and / or other controllers 36. It is contemplated that while this example demonstrates a one-to-one braking scenario, where strong braking on the towing vehicle 12 corresponds to strong braking of the towed vehicle 14, and vice versa, other braking strategies can be contemplated for the TBMS 10. For example, more advanced braking techniques can be employed to limit or optimize movement of the towed vehicle 14 and the towing vehicle 12 (e.g., different braking frequencies for a common braking input level).

[0050] With continued reference to Figure 3 , the current detector 20 can include a shunt 46, such as a resistor or a Hall sensing element, in series with the switch 18. A current sense amplifier 48 is disposed in parallel with the shunt 46 for detecting a voltage across the shunt 46. The current sense amplifier 48 can include an operational amplifier with a programmable gain and / or a gain set by the controller 30. The voltage across the shunt 46 corresponds to a current level through the shunt 46, and thus through the drive circuitry 11 and components of the towed vehicle 14 or between them. The output of the current sense amplifier 48 can be an analog voltage representative of the current. Other components can be included in the current detector 20 for limiting / filtering the high frequency switching signal. For example, because the PWM signal can act relatively quickly in terms of transitioning between the on state and the off state, the current detector 20 can include one or more capacitors, inductors, and / or resistors to extract particular current conditions of the detected current that can be monitored by a comparator 50. The comparator 50 can include one or more other operational amplifiers, logic gates, processors, or another device to compare the output of the current sense amplifier 48 (which corresponds to the current flowing through the shunt 46) to a power threshold.

[0051] The power threshold can be signed or unsigned. For example, the power threshold can be a negative value (e.g., current flowing to the drive circuitry 11) or a positive current value (e.g., current flowing to components of the towed vehicle 14). Responsive to the comparison, the comparator 50 can be configured to communicate a control signal to the switch 18 to deactivate or activate the switch 18 responsive to the comparison. In other examples, the comparator 50 communicates the comparison to the controller 30, and the controller 30 communicates the control signal to the switch 18. In either example, the switch 18 can be controlled with a relatively low delay from the onset of the current.

[0052] For example, the delay between detection of an atypical or overcurrent condition at the shunt 46 and deactivation of the switch 18 can be between 5 microseconds (ps) and 100 ps. In some examples, the delay is less than 60 ps. In some examples, the delay is between 5 ps and 60 ps. The atypical or overcurrent condition can include current exceeding / being below a threshold current. For example, if current is detected flowing to the drive circuitry 11 through the ground node (e.g., in a reverse battery condition), the switch 18 can be controlled to be deactivated. Additionally, the upstream switch 37 can be deactivated responsive to any current flowing through the high-side drive circuit 38. In some examples, the upstream switch 17 includes a diode biased with respect to the drive circuit 11 to limit current flow from the drive circuitry 11 to the power source. For example, in a vehicle off state, the switch 18 and the upstream switch 37 can be in a deactivated state. By providing a fast reaction time to detection of a current condition, an overcurrent experienced by the drive circuitry 11 can be limited, thereby limiting an inoperable condition of the drive circuitry 11. It is contemplated that the switch 18 can be normally open or normally closed such that a control signal can cause activation or deactivation of the switch 18.

[0053] It is contemplated that the interruption provided by the switch 18 can interrupt uncontrolled and / or reverse feed current from returning to the trailer 14. For example, when the disconnect switch 56 is closed when the towed vehicle 14 is electrically coupled with the towing vehicle 12 and the vehicle is parked, the low-side drive circuit 40 can be activated to connect the drive circuitry 11 to the chassis ground. Because the drive circuitry 11 is connected to ground in this example (or in an off state, the body diode connects the first node 42 with ground), when the disconnect switch 56 is pulled with the reverse power source 22 (e.g., circuit closed), current from the power source 22 can travel from the positive terminal of the battery, through the ground node, through the low-side drive circuit 40, and through the first node 42. In this example, the current detector 20 and the switch 18 arrangement limit current from reaching the output node 16. As previously described, current can flow through the high-side drive circuit 38 due to the body diode of the high-side drive circuit 38, but current flow to the power input can be limited by interrupting the current flow through the upstream switch 37.

[0054] When the vehicle is off, switch 18 is off, so there is no current path for an external reverse battery condition. The question is when 18 is turned on. The present strategy is to disable / latch off switch 18 and present a message on the screen to notify the user of the reverse battery condition. The user can then acknowledge the message (e.g., via user input) before the latch is disabled. In some examples, the voltage at output node 16 is monitored by controller 30 to determine if a reset condition exists for switch 18. Various reset conditions can be implemented.

[0055] Continue to refer Figure 3 , a latch circuit 52 can be provided in or in communication with the detector to maintain the disabled state of the switch 18 after the disable condition. For example, the latch circuit 52 can include one or more logic gates including transistors that can control the setting and resetting of the control signal. Thus, the switch 18 can remain open after the disconnect condition to limit further attempts to re-create the conditions that caused the disconnect condition. For example, a user can connect the battery of the towed device in reverse (e.g., the negative terminal of the battery is connected to the output node 16 and the positive terminal of the battery is connected to the chassis). It is contemplated that, if Figure 3 As shown, a series fuse 54 or circuit breaker and / or disconnect switch 56 can be between the output node 16 and the battery. Therefore, the connection between the output node 16 and the battery can include one or more intermediate nodes. When the user disconnects the disconnect switch 56 to close the circuit, current can flow from the battery through the ground node, the low-side drive circuit 40 and through the current detector 20. In response to the current, the current detector 20 can activate or deactivate the switch 18 to limit the overcurrent condition. The controller 30 can also monitor the state of the drive circuit system (e.g., the activation of the high-side drive circuit 38) to determine the reverse battery condition. For example, if a current is detected flowing through the switch 18 when the high-side drive circuit 38 is not activated, the controller 30 can determine the reverse battery state. The latch circuit 52 can maintain the switch 18 in the interrupt condition after the switch 18 is turned off.

[0056] The controller 30 may provide a reset signal to the latch circuit 52 to interrupt the latch circuit 52 in response to one or more conditions (such as a user override, a time delay, an electrical condition, an inspection of the system 10, etc.). For example, the controller 30 may transmit a voltage or current to the latch circuit 52 to unlatch the control signal from the switch 18, thereby causing the switch 18 to be activated. Conversely, the controller 30 may be configured to track a count of the number of resets over a period of time and limit the resetting of the latch after a predetermined number of resets. After the reset limit is reached, the controller 30 may transmit an indication to a notification device so that the user does not retry testing the power supply 22 without making adjustments. As will be described with respect to Figure 4As described, after latching of the latching circuit 52, a user can be notified that a reverse battery condition has been detected via the user interface 34 or another notification device. For example, because the controller 30 can monitor the latch and / or the detector. The current detector 20 and / or the switch 18 and / or the drive circuitry 11, the controller 30 can communicate information to the other controller 36 and / or the user interface 34 to notify the user of the condition of the TBMS 10. In this way, the user can be made aware of one or more conditions of the tow vehicle 12.

[0057] Referring now to Figure 4 , a process 400 for identifying and notifying of a reverse condition of the power source 22 is shown. At step 402, there is a reverse battery condition. For example, a user can connect the battery in reverse (e.g., positive to negative and negative to positive). At step 404, the disconnect switch 56 can be released. For example, with the towed vehicle 14 electrically decoupled from the towing vehicle 12, a user can disconnect the disconnect switch 56 to test the braking function. Thus, a user can simulate this condition by disconnecting the disconnect switch 56 after installing the battery. In this condition, at step 406, current can flow back toward the drive circuitry 11 through the ground node, the low-side drive circuit 40, and the current detector 20. At step 408, the current detector 20 detects the reverse current and, at step 410, the switch 18 is opened. At step 412, a notification is presented to the user via, for example, the user interface 34. By way of example, the controller 30 can communicate an indication of the signal indicative of the reverse battery condition to the notification device.

[0058] Generally, the TBMS 10 herein can limit overcurrent conditions and provide notification of a reverse battery installation condition.

[0059] As used herein, the term “and / or,” when used between two or more items, means that an item can be employed individually or any combination of two or more of the items can be employed. For example, if a composition is described as containing components A, B, and / or C, the composition can contain: only A; only B; only C; a combination of A and B; a combination of A and C; a combination of B and C; or a combination of A, B, and C.

[0060] In this document, relational terms such as first and second, top and bottom, and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises," "comprising," or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0061] As used herein, the term "about" means quantities, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but can be approximated and / or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and other factors that are well-known per se to those skilled in the art. When the term "about" is used in reference to a value or to a range of values or to endpoints of a range, the disclosure shall be understood to encompass the specific value or values or the endpoint or endpoints specified, as well as values or endpoints close thereto. Values or endpoints "about" each of the other are intended to encompass both embodiments where exactly that value or endpoint is used, and embodiments where only a value or endpoint close to that value or endpoint is used. It is also understood that the endpoints of the ranges are themselves explicitly included within the range.

[0062] The terms "substantial," "substantially," and variations thereof as used herein are intended to note that a described feature is equal or approximately equal to a value or description. For example, a "substantially planar" surface is intended to denote a surface that is planar or approximately planar. Also, "substantially" is intended to denote that two values are equal or approximately equal. In some embodiments, "substantially" can denote values within about 10% of each other, such as within about 5% of each other, or within about 2% of each other.

[0063] As used herein, the term "said," "one," or "a" means "at least one" and should not be limited to "only one" unless explicitly indicated as such. Thus, for example, reference to "a component" includes embodiments having two or more such components unless the context clearly indicates otherwise.

[0064] It is understood that the foregoing structural descriptions are subject to change and modification without departing from the concept of the present disclosure, and it is also understood that such concepts are intended to be covered by the claims appended hereto unless otherwise expressly excluded by the language thereof.

[0065] According to the invention, there is provided a braking system having: drive circuitry configured to transmit a brake signal from a towing vehicle to a towed vehicle connected to the towing vehicle; an output node configured to carry the brake signal; a switch electrically interposed between the drive circuitry and the output node; and a current detector in series with the switch and configured to detect a current through the drive circuitry, wherein the switch is configured to electrically connect and electrically disconnect the drive circuitry from the output node in response to the current.

[0066] According to an embodiment, the output node is configured to be electrically coupled with a power source on the towed vehicle, the power source having a positive terminal and a negative terminal.

[0067] According to an embodiment, the current detector detects the current flowing through the drive circuitry in response to the output node being coupled with the negative terminal.

[0068] According to an embodiment, the current detector comprises: a shunt in series with the switch; and at least one current sense amplifier having a programmable gain and configured to output a voltage representative of the current through the shunt.

[0069] According to an embodiment, the invention further features: a comparator configured to control the switch in response to the voltage representative of the current flowing through the drive circuitry.

[0070] According to an embodiment, the comparator is configured to disable the switch in response to the current flowing through the drive circuitry and a state of the drive circuitry.

[0071] According to an embodiment, the invention further features: a latch circuit configured to keep the switch disabled after the switch is disabled.

[0072] According to an embodiment, the invention further features: a controller in electrical communication with the current detector and configured to selectively release the latch circuit.

[0073] According to an embodiment, the invention further features: a user interface configured to present an indication of a reverse battery condition of the towed vehicle in response to detecting the current when the drive circuitry is powered off.

[0074] According to an embodiment, the output node is electrically coupled with at least one brake of the towed vehicle, the at least one brake configured to actuate in response to the brake signal.

[0075] According to the invention, there is provided a braking system having: drive circuitry configured to transmit a brake signal from a towing vehicle to a towed vehicle connected to the towing vehicle; an output node configured to carry the brake signal; a switch electrically interposed between the drive circuitry and the output node; and a current detector in series with the switch and configured to detect a current flowing through the drive circuitry and to the switch, wherein the switch is configured to electrically connect and electrically disconnect the drive circuitry from the output node in response to the current.

[0076] According to embodiments, the output node is configured to be electrically coupled with a power source on the towed vehicle, the power source having a positive terminal and a negative terminal, wherein the current detector detects a current flowing through the drive circuitry in response to the output node being coupled with the negative terminal.

[0077] According to embodiments, the current detector comprises: a shunt in series with the switch; and at least one current sense amplifier configured to output a voltage representative of a current through the shunt.

[0078] According to embodiments, the invention further features: a comparator configured to control the switch in response to the voltage representative of the current flowing through the drive circuitry.

[0079] According to embodiments, the comparator is configured to disable the switch in response to the current flowing through the drive circuitry.

[0080] According to embodiments, the invention further features: a latch circuit configured to maintain the switch disabled after the switch is disabled.

[0081] According to embodiments, the invention further features: a controller in electrical communication with the current detector and configured to selectively release the latch circuit.

[0082] According to embodiments, the invention further features: a user interface configured to present an indication of a reverse battery condition of the towed vehicle in response to detecting the current flowing through the drive circuitry.

[0083] According to embodiments, the output node is electrically coupled with at least one brake of the towed vehicle, the at least one brake configured to actuate in response to the brake signal.

[0084] According to the invention, there is provided a brake system having: drive circuitry configured to transmit a brake signal from a towing vehicle to a towed vehicle connected to the towing vehicle; an output node configured to carry the brake signal; a switch electrically interposed between the drive circuitry and the output node; a current detector in series with the switch and configured to detect a current through the drive circuitry, wherein the switch is configured to electrically connect and electrically disconnect the drive circuitry from the output node in response to the current; a shunt in series with the switch; at least one current sense amplifier configured to output a voltage representative of a current through the shunt; and a comparator configured to control the switch in response to the voltage representative of the current flowing through the drive circuitry.

Claims

1. A braking system comprising: a drive circuit system configured to transmit a brake signal from a towing vehicle to a towed vehicle connected to the towing vehicle; an output node configured to carry the brake signal; a switch electrically interposed between the drive circuitry and the output node; as well as A current detector is connected in series with the switch and is configured to detect a current through the drive circuitry, wherein the switch is configured to electrically connect and disconnect the drive circuitry from the output node in response to the current. 2 . The braking system of claim 1 , wherein the output node is configured to be electrically coupled to a power source on the towed vehicle, the power source having a positive terminal and a negative terminal. 3 . The brake system of claim 2 , wherein the current detector detects current flowing through the drive circuitry in response to the output node being coupled to the negative terminal.

4. The braking system according to claim 3, wherein the current detector comprises: a shunt connected in series with the switch; as well as At least one current sense amplifier has a programmable gain and is configured to output a voltage representative of the current through the shunt.

5. The braking system according to claim 4, further comprising: A comparator is configured to control the switch in response to the voltage representing the current flowing through the drive circuitry. 6 . The braking system of claim 5 , wherein the comparator is configured to disable the switch in response to the current flowing through the drive circuitry and a state of the drive circuitry.

7. The braking system according to claim 6, further comprising: A latch circuit is configured to keep the switch disabled after disabling the switch.

8. The braking system according to claim 7, further comprising: A controller is in electrical communication with the current detector and is configured to selectively release the latch circuit.

9. The braking system according to claim 6, further comprising: A user interface is configured to present an indication of a reverse battery condition of the towed vehicle in response to detecting the current flow when the drive circuitry is de-energized.

10. The braking system of any one of claims 1 to 9, wherein the output node is electrically coupled to at least one brake of the towed vehicle, the at least one brake being configured to actuate in response to the braking signal.

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