Apparatus for providing parallel filtering

Abstract

The invention relates to an apparatus for providing parallel filtering. In at least one embodiment, a system is provided that includes a first circuit and a second circuit. The first circuit includes a first filter that filters a first input signal and generates a first filtered output signal. The first circuit includes a first comparator that compares the first filtered output signal to a first threshold and provides a first output signal indicative of a fault condition to one or more first processors. The second circuit includes a second filter that filters the first input signal and generates a second filtered output signal to filter the first input signal for a shorter time than the first filter filters the first input signal. The second circuit includes a second comparator that compares the second filtered output signal to a second threshold and provides a second output signal indicative of the fault condition to one or more second processors.

Description

Technical Field

[0001] Aspects disclosed herein generally relate to a system for providing parallel filtering. These and other aspects will be discussed in more detail herein. Brief Description of the Drawings

[0003] Figure 1 An apparatus for providing parallel filtering according to one embodiment is depicted;

[0004] Figure 2 An equivalent circuit is depicted that indicates how a first time constant and a second time constant are determined according to one embodiment; and

[0005] Figure 3 Various measurements of a sense voltage and a response time for disabling a charging operation are depicted. Detailed Description

[0007] As needed, detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely examples of the present invention, and the present invention may be embodied in various forms and alternative forms. The drawings are not necessarily to scale; some features may be enlarged or minimized to show details of particular components. Accordingly, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to practice the present invention in various ways.

[0008] Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the various described embodiments. However, it will be apparent to one of ordinary skill in the art that the various described embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, circuits, and networks have not been described in detail so as not to unnecessarily obscure aspects of the embodiments.

[0009] It should be understood that the disclosed embodiments are merely exemplary, and that various and alternative forms are possible. The drawings are not necessarily to scale; some features may be enlarged or minimized to show details of particular components. Accordingly, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to practice embodiments in accordance with the present disclosure in various ways.

[0010] "One or more" and / or "at least one" includes functions performed by one element, such as functions performed by more than one element in a distributed manner, several functions performed by one element, several functions performed by several elements, or any combination of the above.

[0011] It should also be understood that although in some cases, the terms first, second, etc. are used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first contact can be referred to as a second contact, and similarly, a second contact can be referred to as a first contact, without departing from the scope of the various embodiments described. Both the first contact and the second contact are contacts, but they are not the same contact.

[0012] The terms used in the description of the various embodiments described herein are for the purpose of describing particular embodiments only and are not intended to be limiting. As used in the description of the various embodiments and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the phrase "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. It should be further understood that when used in this specification, the words "includes", "including", "comprises", and / or "comprising" specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0013] As used herein, the word "if" is optionally interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if determined" or "if detected [the condition or event]" is optionally interpreted to mean "when determining" or "in response to determining" or "when detecting [the condition or event]" or "in response to detecting [the condition or event]", depending on the context.

[0014] Aspects disclosed herein generally provide a system for performing parallel filtering on a sensing circuit. The sensing circuit senses an input voltage, such as that of an on-board charging device (OBC). The disclosed system includes a first circuit including at least a first filter and a second circuit including at least a second filter. Each of the first circuit and the second circuit receives a first input signal indicative of at least a sensed voltage condition in the system. The first filter operates at a first operating frequency, and the second filter operates at a second operating frequency. The second operating frequency of the second filter is greater than the first operating frequency, such that the second circuit can detect a fault condition in the system faster than the first circuit. Generally, the second circuit outputs an output signal for transmission to one or more processors (or microprocessors and / or digital signal processors (DSPs)) in the system to quickly disable the system and thereby mitigate the fault condition.

[0015] The first circuit also detects the fault condition. However, since the first operating frequency is less than the second operating frequency, this detection is performed over a longer time than the time it takes for the second circuit to detect the fault condition. In this case, the first circuit detects the fault condition to report the detected fault condition to other processors (e.g., for diagnostic purposes in a vehicle and / or for use as a redundancy check on the first circuit). Thus, the first circuit may not need to detect the fault condition at the same rate as the second circuit.

[0016] The first operating frequency of the first filter and the second operating frequency of the second filter are based on a first time constant and a second time constant, respectively. As disclosed herein, there is a correlation between the electronics used to form the first and second circuits and the various time constants at which the first and second filters operate. For example, the first time constant can be derived based on the values of a first resistor and capacitor network of the first filter. Similarly, the second time constant can be derived based on the values of a second resistor and capacitor network of the second filter. Other embodiments for detecting fault conditions via parallel filtering methods in a system utilize buffer circuits (or operational amplifiers) to isolate the filters from each other. The disclosed system eliminates the need for buffer circuits. Additionally, the disclosed system provides a fault detection mechanism that can be applied to any number of applications having different delay times, different alarm thresholds, different responses to ramp or step behavior, etc. Further, the disclosed system can be well-suited for applications that require a redundancy detection mechanism in place to provide any number of parallel measurements.

[0017] Figure 1Depicts a system 100 (or apparatus) for providing parallel filtering and for detecting a fault condition according to one embodiment. System 100 generally includes a first circuit 102 and a second circuit 104. It should be recognized that system 100 may include any number of circuits that may operate similar to either the first circuit 102 and / or the second circuit 104. Generally, each of the first circuit 102 and the second circuit 104 is configured to detect a fault condition (or failure condition) (e.g., overvoltage condition, undervoltage condition, overcurrent condition, and / or undercurrent condition) attributable to a sensed input (e.g., sensed voltage or sensed current). In one example, system 100 detects a fault condition of an on-board charger (OBC) 103 in a vehicle 105. It is contemplated that system 100 may be used in any application configured to detect a fault condition.

[0018] System 100 includes a sensed input circuit 130 that provides a first input signal indicative of a sensed voltage to the first circuit 102 and the second circuit 104. The first circuit 102 includes a first filter 110 and a first comparator 114. A first resistor and capacitor network 113 generally forms the first filter 110. The first resistor and capacitor network 113 includes a resistor R1 and a capacitor C1. In one example, the first filter 110 is a low-pass filter. It should be recognized that the first filter 110 may be a high-pass filter, a band-pass filter, etc. The first filter 110 filters the input sensed voltage and provides an output to the first comparator 114. The first comparator 114 compares the output from the first filter 110 with a threshold and then outputs a first output signal indicative of a detected fault based on the comparison.

[0019] When performing a filtering operation, the first filter 110 operates at a first frequency. The relevance of the first frequency will be discussed in more detail below. The first circuit 102 provides an output (or a first output signal) indicating the presence of a fault detection condition in the system 100 to one or more first processors 120 (“the first processors 120”). The first processors 120 may include one or more first microcontrollers or one or more first digital signal processors (DSPs). It should be recognized that the first DSP may operate faster than the first microcontroller. The first processors 120 report the presence of a fault as a diagnostic feature and may send an indication of the detected fault condition to warn the user of the condition. The fault condition may correspond to an overvoltage condition, an undervoltage condition, an overcurrent condition, or an undercurrent condition. In the case of detecting an overcurrent condition or an undercurrent condition, the first circuit 102 reports such a condition to the first DSP because the response speed of the first DSP is faster than that of the first microcontroller. In the case of detecting an overvoltage condition or an undervoltage condition, the first circuit 102 reports such a condition to the first microcontroller because the faults associated with the overvoltage condition and the undervoltage condition may not have the same priority as the detected overcurrent condition and undercurrent condition.

[0020] In a similar manner, the second circuit 104 also provides an output (or a second output signal) in response to detecting a fault condition to one or more second processors 122 (i.e., “the second processors 122”). The second processors 122 may include one or more second microcontrollers or one or more second digital signal processors (DSPs). It should be recognized that the second DSP may operate faster than the second microcontroller. For example, the second circuit 104 receives a first input signal indicating the sensed voltage (or current) in the system 100 from the sensing input circuit 130. The second circuit 104 includes a second filter 112a and a second comparator 116a. The second resistor and capacitor network 115 generally forms the second filter 112a. The second resistor and capacitor network 115 includes a resistor R2a and a capacitor C2a. In one example, the second filter 112a is a low-pass filter. It should be recognized that the second filter 112a may be a high-pass filter, a band-pass filter, etc. The second filter 112a filters the input sensed voltage and provides an output (e.g., a second output signal) to the second comparator 116a. The second comparator 116a compares the output from the second filter 112a with a threshold and then outputs a second output signal indicating the detected fault based on the comparison.

[0021] The second filter 112a operates at a second frequency when performing a filtering operation. The second frequency can be greater than the first frequency used by the first filter 110. The second circuit 104 provides a second output signal indicating the presence of a fault detection condition in the system 100 to one or more second processors 122. In response to detecting a fault condition, the second processor 122 disables the system 100 to prevent the fault condition from damaging the electronics or other devices in the system 100. In one example, the second processor 122 (e.g., the second DSP) can disable the charging operation being performed between the OBC 103 and the vehicle 105 in microseconds. The fault condition can correspond to an overvoltage condition, an undervoltage condition, an overcurrent condition, or an undercurrent condition.

[0022] Generally, the task of the second circuit 104 is to detect the fault condition as quickly as possible because when the fault condition is detected, the second circuit 104 transmits the second output signal to the second processor 122 to disable the system 100 (or the OBC 103). For example, the second processor 122 can control any number of DC-to-DC converters (not shown) that convert a high-voltage input signal during the charging operation of the vehicle 105. Upon detecting or receiving the second output signal from the second circuit 104, the second processor 122 disables the battery charging operation based on the high-voltage conversion that has occurred to mitigate any potential problems. As described above, the first processor 120 in conjunction with the first circuit 102 can detect the presence of a fault condition in response to receiving the first output signal from the first circuit 102 and notify other microprocessors (or controllers) in the vehicle 105 that a fault condition related to the vehicle charging operation (e.g., an overvoltage condition or an undervoltage condition) has been detected. However, the first processor 120 may not be directly responsible for controlling the various DC / DC converters that perform energy conversion during the battery charging operation and may simply record the presence of the fault detection in the presence of such a condition so that other measures can be taken. However, if the first circuit 102 is arranged to detect an overcurrent condition or an undercurrent condition, the first circuit 102 reports such a condition to both the first microcontroller and the first DSP of the first processor 120. The first output signal output by the first circuit 102 can be used as a redundant output and is used to disable the charging operation in the event that the second processor 122 fails to operate properly.

[0023] Accordingly, by operating the second filter 112a of the second circuit 104 at a second frequency greater than the first frequency of the first circuit 102, the second circuit 104 is configured to process (e.g., filter a first input signal indicative of a sensed voltage or current using the second filter 112a) faster than the first circuit 102 (e.g., faster than the first filter 110), and thus detect a fault condition earlier in time when observed with reference to the first circuit 102. The second circuit 104 is also capable of reporting a fault detection to the second processor 122 faster than the first circuit 102 is capable of reporting a fault condition to the first processor 120.

[0024] The second circuit 104 includes a third filter 112b and a third comparator 116b. Each of the first filter 110, the second filter 112a, and the third filter 112b is included in the system 100 because each input provided by these filters 110, 112a, and 112b is an independent reading from one another, and thus provides a redundant measurement circuit. The third resistor and capacitor network 117 generally forms the third filter 112b. The third resistor and capacitor network 117 includes a resistor R2b and a capacitor C2b. In one example, R2b is equal to R2a, and C2b is equal to C2a. In another example, the third filter 112c is a low-pass filter. It should be appreciated that the third filter 112c can be a high-pass filter, a band-pass filter, etc. The third filter 112b filters the input sensed voltage and provides an output to the third comparator 116b. The third comparator 116b compares the output from the third filter 112a with a threshold and then outputs a third output signal indicative of a detected fault based on the comparison.

[0025] The third filter 112b operates at a third frequency when performing the filtering operation. The third frequency can be greater than the first frequency used by the first filter 110. In one example, the third frequency can be similar to (or equal to) the second frequency of the second filter 112a. The third circuit 112b also provides a third output signal to the second processor 122 indicative of the presence of a fault detection condition in the system 100. As described above, in response to detecting a fault condition, the second processor 122 disables the system 100 to prevent the fault condition from damaging the electronics or other devices in the system 100.

[0026] The task of the second circuit 104 is to detect a fault condition as quickly as possible because when a fault condition is detected, the second circuit 104 transmits a second output signal to the second processor 122 to disable the system 100 (or the OBC 103). Thus, by operating the third filter 112b of the second circuit 104 at a second frequency greater than the first frequency of the first circuit 102, the second circuit 104 is configured to process (e.g., filter the first input signal indicative of the sensed voltage using the second filter 112a) faster (or in a shorter time) than the first circuit 102 and thus detect the fault condition earlier in time when observed with reference to the first circuit 102. The second circuit 104 is also capable of reporting a fault detection to the second processor 122 faster than the first circuit 102 is capable of reporting a fault condition to the first processor 120. In one example, assuming that the second filter 112a and the third filter 112b operate at the second frequency (and also have a greater frequency range), the second processor 122 disables the OBC 103 based on receiving the second output signal from the second circuit 104 before the first processor 120 reports the fault condition based on receiving the first output from the first circuit 102.

[0027] The input threshold resistors Rin1, Rin2, and Rin3 of the first comparator 114, the second comparator 116a, and the third comparator 116b provide a threshold voltage V TH (or threshold current) for each of the first comparator 114, the second comparator 116a, and the third comparator 116b. Thus, the resistance values of the input threshold resistors Rin1, Rin2, and Rin2 can be selected such that the first comparator 114, the second comparator 116a, and the third comparator 116b can provide outputs indicative of an overvoltage condition, an undervoltage condition, an overcurrent condition, and / or an undercurrent condition. Although two circuits 102 and 104 are shown, it should be appreciated that any number of circuits may be included in the system 100 to provide a plurality of outputs corresponding to the detected overvoltage conditions.

[0028] Generally, the operating frequencies (e.g., the first frequency of the first filter 110, the second frequency of the second filter 112a, and the third frequency of the third filter 112b) can be calculated by the following equation, which is a function of the time constant (e.g., “τ”):

[0029]

[0030] Accordingly, in this regard, the selection of the specific resistance values and capacitance values (e.g., R1 and C1) of the first resistor-capacitor network 113 at least partially establishes the first frequency (or f1). Similarly, the specific resistance values and capacitance values (e.g., R2a, C2a) of the second capacitor network 115 and the specific resistance values and capacitance values (e.g., R2b, C2b) of the third capacitor network 117 at least partially form the second frequencies of the second filter 112a and the third filter 112b, respectively. In one example, both the second filter 112a and the third filter 112b can operate at the second frequency. In this regard, the resistance value of R2a and the capacitance value of C2a of the second resistor and capacitor network 115 are equal to the resistance value of R2b and the capacitance value of C2b of the third resistor and capacitor network 117. In another example, it should be appreciated that the second filter 112a and the third filter 112b can operate at different frequencies from each other, but can still be arranged to operate faster than the first filter 113. In this regard, the resistance values of R2a and R2b can be different from each other and / or the capacitance values of C2a and C2b can be different from each other. By selecting various values of the RC network for the first filter 110, the second filter 112a, and / or the third filter 112 to achieve the desired frequencies for controlling the speed at which the first circuit 102 and the second circuit 104 measure the sensed voltage, such an implementation improves performance, eliminates the need for additional electronics, and achieves cost savings.

[0031] Figure 2 Equivalent circuit 200 is depicted, which indicates the manner in which a first time constant (e.g., τ1) and a second time constant (e.g., τ2) are determined according to one embodiment. The first frequency of the first filter 110 is based on the first time constant (e.g., τ1). Similarly, the second frequencies of the second filter 112a and the third filter 112b are based on the second time constant (e.g., τ2), assuming that both the second filter 112a and the third filter 112b operate at the same frequency. As described above, the second filter 112a and the third filter 112b can operate at different frequencies from each other, provided that such frequencies enable the second filter 112a and the third filter 112b to operate faster (or perform filtering operations) than the first filter 110.

[0032] Circuit 200 generally corresponds to aspects shown in connection with the first circuit 102, the second circuit 104, and the sense input circuit 130. For example, circuit 200 includes resistors R1, R2, Rd1, and Rd2 and capacitors C1, C2. The first time constant τ1 is generally defined (or formed) based on the following equation:

[0033] τ1 = C1 * (R1 + R th ) (2)

[0034] where Rth = Rd1 || Rd2.

[0035] The second time constant τ2 is typically defined (or formed) based on the following equation:

[0036] τ2 = C2 * (R2 + R th || R1) (3)

[0037] where C2 = 2 * C2a and R2 = R2a / 2.

[0038] Conversely, the first time constant τ1 and the second time constant τ2 can be provided as follows: τ1 = C1 * (R1) or τ2 = C2a * (R2a) (or τ2 = C2b * (R2b)). Thus, as shown, the various resistance values of the resistors R1, R2a, Rd1, Rd2 and the capacitance values of the capacitors C1 and C2a can be used to generate the first time constant and the second time constant based on the equations shown above. The first time constant and the second time constant can be used to derive the first frequency and the second frequency of the first filter 110 and the second filter 112a and thus the third filter 112b based on the above equation (1). In summary, it can be seen that the first time constant is greater than the second time constant (or τ1 > τ2) so that the first frequency of the first filter 110 is less than the second frequency of the second filter 112a and the third filter 112b, (e.g., so that the second filter 112a (or the third filter 112b) operates faster than the first filter 110).

[0039] Figure 3 A table 200 is depicted showing various measurement results of the sense voltage and the response time for disabling the charging operation. Generally, the table 200 includes a first column 202, a second column 203, a third column 204 and a fourth column 206. The first column 202 generally corresponds to various sense signals of voltage or current. The second column 203 generally corresponds to various signal parameters. The third column 204 generally corresponds to a first measurement performed by a system that does not include aspects of the disclosed system 100. The fourth column 206 generally corresponds to a second measurement performed by the disclosed system 100.

[0040] In one example, the sensed signals as shown in the first column 202 of the table 200 correspond to the sensed voltage or current on the HV network in the vehicle 105. In another example, the sensed signals in the first column 202 of the table 200 correspond to the sensed voltage or current on the low voltage (LV) network in the vehicle 105. The second column 203 depicts various parameters corresponding to the sensed characteristics (e.g., voltage or current). The third column 204 depicts the various measurement times performed by different systems (not the disclosed system 100) for each of the sensed voltages and currents shown in the first column 202. The fourth column 206 depicts the various measurement times performed by the first circuit 102 of the system 100 for each of the sensed voltages and currents shown in the first column 202.

[0041] Generally, as shown, at 250, different systems measure the sensed voltage on the HV network at 51 μs, while the system 100 (or the second circuit 104) as disclosed herein typically measures the sensed voltage on the HV network at 12 μs. Generally, as shown, at 252, different systems measure / detect the sensed current on the HV network at 356 μs, while the system 100 (or the second circuit 104) as disclosed herein measures / detects the sensed current on the HV network at 33 μs. Generally, as shown, at 254, different systems typically measure the sensed voltage on the LV network at 736 μs, while the system 100 (or the second circuit 104) as disclosed herein typically measures / detects the sensed voltage on the LV network at 28 μs. Generally, as shown, at 256, different systems typically measure / detect the sensed current on the HV network at 202 μs, while the system 100 (or the second circuit 104) as disclosed herein measures / detects the sensed current on the HV network at 40 μs. Thus, in any one or more cases, the system 100 exhibits a faster response cycle than different systems.

[0042] Item 1. A system includes a first circuit and a second circuit. The first circuit includes a first filter that filters a first input signal indicative of at least a sensed voltage condition in the system, and the first filter generates a first filtered output signal in response to filtering the first input signal at a first frequency. The first circuit includes a first comparator that compares the first filtered output signal with a first threshold and provides a first output signal indicative of a fault condition to one or more first processors to report the fault condition based on the comparison of the first filtered output signal with the first threshold. The second circuit includes a second filter that filters the first input signal indicative of at least a sensed voltage condition in the system, and the second filter generates a second filtered output signal in response to filtering the first input signal at a second frequency greater than the first frequency, such that the second filter is capable of filtering the first input signal in a shorter time than the first filter filters the first input signal. The second circuit includes a second comparator that compares the second filtered output signal with a second threshold and provides a second output signal indicative of a fault condition to one or more second processors to disable the system based on the comparison of the second filtered output signal with the second threshold before one or more first processors report the fault condition.

[0043] Item 2. According to Item 1, the second circuit includes a third filter that filters the first input signal indicative of at least a sensed voltage condition, and wherein the third filter generates a third filtered output signal in response to filtering the first input signal at a second frequency greater than the first frequency, such that the second filter is capable of filtering the first input signal in a shorter time than the first filter filters the first input signal.

[0044] Item 3. According to Item 2, the second circuit includes a third comparator that compares the third filtered output signal with a third threshold and provides a third output signal indicative of a fault condition to one or more second processors, and before one or more first processors report the fault condition, one or more second processors disable the system based on the comparison of the second filtered output signal with the third threshold voltage.

[0045] Item 4. According to Item 3, the third threshold for the third comparator is different from the second threshold for the second comparator.

[0046] Item 5. According to Item 4, the second comparator outputs a signal indicative of an overvoltage condition based on the comparison of the second filtered output signal with the second threshold.

[0047] Item 6. According to Item 4, the third comparator outputs a signal indicative of an undervoltage condition based on the comparison of the third filtered output signal with the third threshold.

[0048] Item 7. According to Item 1, the first frequency of the first filter is based on a first time constant, and the second frequency of the second filter is based on a second time constant, and wherein the first time constant is different from the second time constant.

[0049] Item 8. According to Item 7, the first time constant is greater than the second time constant.

[0050] Item 9. According to Item 7, further comprising a sensing input circuit including at least one sensing resistor electrically connected to the first filter and the second filter, the sensing input circuit providing a first input signal indicative of a sensed voltage condition.

[0051] Item 10. According to Item 9, the first time constant and the second time constant are each partially based on the resistance value of the at least one sensing resistor.

[0052] Item 11. According to Item 7, the first filter is formed by a first resistor and capacitor network, and the second filter is formed by a second resistor and capacitor network.

[0053] Item 12. According to Item 11, the first time constant is at least partially based on a first resistance value and a first capacitance value of the first resistor and capacitor network, and the second time constant is at least partially based on a second resistance value and a second capacitance value of the second resistor and capacitor network.

[0054] Item 13. According to Item 1, the first filter is a low-pass filter.

[0055] Item 14. According to Item 1, wherein the second filter is a low-pass filter.

[0056] Item 15. A system includes a first circuit and a second circuit. The first circuit includes: a first filter and a first comparator. The first filter filters a first input signal indicative of at least a sensed voltage condition. The first filter generates a first filtered output signal in response to filtering the first input signal at a first frequency. The first comparator compares the first filtered output signal with a first threshold and provides a first output signal indicative of a fault condition to one or more first processors to report the fault condition based on the comparison of the first filtered output signal with the first threshold. The second circuit includes a second filter. The second filter filters the first input signal indicative of at least the sensed voltage condition in the system. The second filter generates a second filtered output signal in response to filtering the first input signal at a second frequency greater than the first frequency such that the second filter can filter the first input signal in a shorter time than the first filter filters the first input signal. The second circuit includes a second comparator. The second comparator compares the second filtered output signal with a second threshold and provides a second output signal indicative of a fault condition to one or more second processors. The first frequency of the first filter is at least based on a first time constant, and the second frequency of the second filter is at least based on a second time constant, and the second time constant is less than the first time constant such that the second filter filters the first input signal in a shorter time than the first filter filters the first input signal.

[0057] Item 16. According to Item 15, the system includes a sensing input circuit. The sensing input circuit includes at least one sensing resistor. The at least one sensing resistor is electrically connected to the first filter and the second filter. The sensing input circuit provides the first input signal indicative of the sensed voltage condition.

[0058] Item 17. According to Item 16, the first time constant and the second time constant are each partially based on the resistance value of the at least one sensing resistor.

[0059] Item 18. According to Item 15, the first filter is formed by a first resistor and capacitor network, and the second filter is formed by a second resistor and capacitor network.

[0060] Item 19. According to Item 18, the first time constant is at least partially based on the first resistance value and the first capacitance value of the first resistor and capacitor network, and the second time constant is at least partially based on the second resistance value and the second capacitance value of the second resistor and capacitor network.

[0061] Item 20. A system includes a first filter, a first comparator, and a second filter. The first filter filters a first input signal indicative of at least a sensed voltage condition in the system, and the first filter generates a first filtered output signal in response to filtering the first input signal at a first frequency. The first comparator compares the first filtered output signal with a first threshold and provides a first output signal indicative of a fault condition to one or more first processors to report the fault condition based on the comparison of the first filtered output signal with the first threshold. The second filter filters the first input signal indicative of at least a sensed voltage condition in the system, and the second filter generates a second filtered output signal in response to filtering the first input signal at a second frequency different from the first frequency such that the second filter is capable of filtering the first input signal in a shorter time than the first filter filters the first input signal. The second comparator compares the second filtered output signal with a second threshold and provides a second output signal indicative of a fault condition to one or more second processors to disable the system based on the comparison of the second filtered output signal with the second threshold before the one or more first processors report the fault condition.

[0062] While the foregoing describes exemplary embodiments, this does not mean that these embodiments describe all possible forms of the invention application. Rather, the words used in this specification are descriptive rather than restrictive words, and it should be understood that various changes can be made without departing from the spirit and scope of the invention application. In addition, features of multiple implementation embodiments can be combined to form additional embodiments of the invention.

Claims

1. A system, comprising: A first circuit, the first circuit comprising: a first filter that filters a first input signal indicative of at least a voltage condition sensed in the system, the first filter generating a first filtered output signal in response to filtering the first input signal at a first frequency, and a first comparator that compares the first filtered output signal to a first threshold and provides a first output signal indicative of a fault condition to one or more first processors to report the fault condition based on the comparison of the first filtered output signal to the first threshold; and A second circuit, the second circuit comprising: a second filter that filters the first input signal indicative of at least the voltage condition sensed in the system, the second filter generating a second filtered output signal in response to filtering the first input signal at a second frequency greater than the first frequency, such that the second filter is able to filter the first input signal in a shorter time than the first filter filters the first input signal, and a second comparator that compares the second filtered output signal with a second threshold, and A second output signal indicative of the fault condition is provided to one or more second processors to disable the system based on a comparison of the second filtered output signal to the second threshold before the one or more first processors report the fault condition.

2. The system according to claim 1, wherein: The second circuit includes a third filter that filters the first input signal indicative of at least the sensed voltage condition, and wherein the third filter generates a third filtered output signal in response to filtering the first input signal at the second frequency greater than the first frequency, such that the second filter is able to filter the first input signal in a shorter time than the first filter filters the first input signal.

3. The system according to claim 2, wherein: The second circuit includes a third comparator that compares the third filtered output signal with a third threshold and provides a third output signal indicative of the fault condition to the one or more second processors, and wherein, before the one or more first processors report the fault condition, the one or more second processors disable the system based on the comparison of the second filtered output signal with the third threshold voltage.

4. The system according to claim 3, wherein: The third threshold for the third comparator is different from the second threshold for the second comparator.

5. The system according to claim 4, wherein: The second comparator outputs a signal indicative of an overvoltage condition based on a comparison of the second filtered output signal and the second threshold.

6. The system according to claim 4, wherein: The third comparator outputs a signal indicative of an under-voltage condition based on a comparison of the third filtered output signal and the third threshold.

7. The system according to claim 1, wherein: The first frequency of the first filter is based on a first time constant and the second frequency of the second filter is based on a second time constant, and wherein the first time constant is different from the second time constant.

8. The system according to claim 7, wherein: The first time constant is greater than the second time constant.

9. The system of claim 7, further comprising a sensing input circuit comprising at least one sensing resistor electrically connected to the first filter and the second filter, the sensing input circuit providing the first input signal indicative of the sensed voltage condition.

10. The system according to claim 9, wherein: The first time constant and the second time constant are each based in part on a resistance value of the at least one sense resistor.

11. The system according to claim 7, wherein: The first filter is formed by a first resistor and capacitor network, and the second filter is formed by a second resistor and capacitor network.

12. The system according to claim 11, wherein: The first time constant is based at least in part on a first resistance value and a first capacitance value of the first resistor and capacitor network, and wherein the second time constant is based at least in part on a second resistance value and a second capacitance value of the second resistor and capacitor network.

13. The system of claim 1, wherein: The first filter is a low pass filter.

14. The system of claim 1, wherein: The second filter is a low pass filter.

15. A system, comprising: A first circuit, the first circuit comprising: a first filter that filters a first input signal indicative of at least a sensed voltage condition, the first filter generating a first filtered output signal in response to filtering the first input signal at a first frequency, and a first comparator that compares the first filtered output signal to a first threshold and provides a first output signal indicative of a fault condition to one or more first processors to report the fault condition based on the comparison of the first filtered output signal to the first threshold; and A second circuit, the second circuit comprising: a second filter that filters the first input signal indicative of at least the voltage condition sensed in the system, the second filter generating a second filtered output signal in response to filtering the first input signal at a second frequency greater than the first frequency, such that the second filter is able to filter the first input signal in a shorter time than the first filter filters the first input signal, and a second comparator that compares the second filtered output signal with a second threshold, and providing a second output signal indicative of the fault condition to one or more second processors, wherein the first frequency of the first filter is based on at least a first time constant, and the second frequency of the second filter is based on at least a second time constant, and The second time constant is smaller than the first time constant, so that the second filter filters the first input signal in a shorter time than the first filter filters the first input signal.

16. The system of claim 15, comprising a sensing input circuit including at least one sensing resistor electrically connected to the first filter and the second filter, the sensing input circuit providing the first input signal indicative of the sensed voltage condition.

17. The system of claim 16, wherein: The first time constant and the second time constant are each based in part on a resistance value of the at least one sense resistor.

18. The system of claim 15, wherein: The first filter is formed by a first resistor and capacitor network, and wherein the second filter is formed by a second resistor and capacitor network.

19. The system of claim 18, wherein: The first time constant is based at least in part on a first resistance value and a first capacitance value of the first resistor and capacitor network, and the second time constant is based at least in part on a second resistance value and a second capacitance value of the second resistor and capacitor network.

20. A system, comprising: a first filter that filters a first input signal indicative of at least a voltage condition sensed in the system, the first filter generating a first filtered output signal in response to filtering the first input signal at a first frequency, and a first comparator that compares the first filtered output signal to a first threshold and provides a first output signal indicative of a fault condition to one or more first processors to report the fault condition to the one or more first processors based on the comparison of the first filtered output signal to the first threshold; and a second filter that filters the first input signal indicative of at least the voltage condition sensed in the system, the second filter generating a second filtered output signal in response to filtering the first input signal at a second frequency different from the first frequency, such that the second filter is capable of filtering the first input signal in a shorter time than the first filter is capable of filtering the first input signal, and a second comparator that compares the second filtered output signal to a second threshold and provides a second output signal indicative of the fault condition to one or more second processors to disable the system based on the comparison of the second filtered output signal to the second threshold before the one or more first processors report the fault condition.

Images