Power failure detection device and method

Abstract

An embodiment of the present disclosure relates to a power outage detection device that can start sending a power outage warning early to ensure that the power outage warning is sent. The device includes a step-down circuit, a detection voltage generating circuit, a detection circuit, and a transmission circuit. The step-down circuit is at least one active element or includes the at least one active element, and is used to generate an output voltage according to an input voltage, wherein the output voltage is lower than the input voltage. The detection voltage generating circuit is coupled between the step-down circuit and a low voltage end, and is used to generate a detection voltage according to the output voltage, wherein the detection voltage is lower than the output voltage and higher than the voltage of the low voltage end. The detection circuit is used to generate a detection result based on the detection voltage and a trigger voltage. The transmission circuit is used to send a power outage warning to a remote device when the detection result indicates that the detection voltage is lower than the trigger voltage.

Description

Technical Field

[0001] The present application relates to a detection device and method, and in particular to a power failure detection device and method. Background Art

[0002] The dying gasp function allows the client device to have enough time to send a special data packet to the central office device after a power outage, so that the central office device can know that the disconnection reason of the client device is a power outage rather than other line problems.

[0003] The current power-off alarm function generates a voltage division of the input voltage of the client device by means of a resistor voltage division method (for example, the voltage division caused by a 3.22KΩ resistor and a 499Ω resistor connected in series), so that the client device sends a special data packet to notify a local device when the voltage division is lower than the trigger voltage, and stops sending the special data packet when the voltage division is higher than the de-trigger voltage. The above-mentioned input voltage is usually a DC voltage of 12 volts (12V). However, the integrated circuit (IC) used to detect the voltage division in the client device cannot withstand excessively high voltages, so the voltage division must usually be lower than 3.3V. As described above, since the input voltage is much higher than the voltage division, the rate of change of the input voltage during power failure will be much greater than the rate of change of the voltage division; in other words, the voltage drop slope of the voltage division is relatively gradual, so that the voltage division cannot quickly drop to the trigger voltage. In addition, in order to avoid false alarms caused by noise interference, the trigger voltage (for example: 1.25V) must be lower than the voltage division (for example: ) reaches a certain level, therefore, when the power is off, the client device must complete sending the special data packet in a very short time; in other words, the time from the time point when the divided voltage is lower than the trigger voltage to the time point when the client device cannot work normally when the power is off (i.e., the hold time) is very short. If the hold time is too short, the client device will not have time to send the special data packet. To avoid the above situation, additional capacitors or capacitors with larger capacitance values ​​will be set on the printed circuit board where the IC is located to help slow down the rate of decrease of the input voltage, thereby increasing the hold time; however, this approach requires a larger printed circuit board to set the capacitor, which not only increases the circuit volume and is not conducive to circuit miniaturization, but also increases the cost. Summary of the invention

[0004] One of the purposes of the present disclosure is to provide a power failure detection device and method to avoid the problems of traditional solutions.

[0005] An embodiment of the power failure detection device disclosed in the present invention includes a step-down circuit, a detection voltage generating circuit, a detection circuit and a transmission circuit. The step-down circuit is at least an active element, or includes the at least one active element, and is used to generate an output voltage according to an input voltage, wherein the output voltage is lower than the input voltage. The detection voltage generating circuit is coupled between the step-down circuit and the low voltage terminal, and is used to generate a detection voltage according to the output voltage, wherein the detection voltage is lower than the output voltage and higher than the voltage of the low voltage terminal. The detection circuit is used to generate a detection result according to the detection voltage and a trigger voltage. The transmission circuit is used to send a power failure warning to a remote device when the detection result indicates that the detection voltage is lower than the trigger voltage. Because the output voltage is lower than the input voltage, the detection voltage can quickly reflect the drop of the input voltage according to the drop of the output voltage, so as to send the power failure warning in time.

[0006] An embodiment of the power off detection method disclosed herein includes the following steps: using a step-down circuit to generate an output voltage according to an input voltage, wherein the output voltage is lower than the input voltage, and the step-down circuit is at least one active element or includes the at least one active element; generating a detection voltage according to the output voltage; generating a detection result according to the detection voltage and a trigger voltage; and sending a power off warning when the detection result indicates that the detection voltage is lower than the trigger voltage.

[0007] The features, implementation and effects of the present invention will be described in detail below with reference to the accompanying drawings as preferred embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 An embodiment of the power failure detection device disclosed in the present invention is shown;

[0009] Figure 2 show Figure 1 An implementation example of a power failure detection device;

[0010] Figure 3 show Figure 1 Another implementation example of the power failure detection device;

[0011] Figure 4 Another embodiment of the power failure detection device disclosed in the present invention is shown;

[0012] Figure 5 show Figure 4 An implementation example of a power failure detection device;

[0013] Figure 6 show Figure 4 Another implementation example of the power failure detection device; and

[0014] Figure 7 An embodiment of the power failure detection method disclosed in the present invention is shown. DETAILED DESCRIPTION

[0015] The present disclosure discloses a power failure detection device and method, which can be used in a client device and can increase the hold time of a dying gasp function.

[0016] Figure 1 An embodiment of a power failure detection device disclosed in the present invention is shown. Figure 1 The power failure detection device 100 includes a voltage reduction circuit 110, a detection voltage generation circuit 120, a detection circuit 130 and a transmission circuit 140. The voltage reduction circuit 110 is at least one active element (for example, a diode) or includes the at least one active element for generating a voltage according to an input voltage (V IN ) generates an output voltage (V OUT ), wherein the output voltage is lower than the input voltage; for example, the output voltage is lower than half of the voltage value of the input voltage. The detection voltage generating circuit 120 is coupled between the step-down circuit 110 and a low voltage terminal (GND) for generating a detection voltage (V DET ), wherein the detection voltage is lower than the output voltage and higher than the voltage value of the low voltage end; for example, the detection voltage is between the output voltage and the low voltage end. The detection circuit 130 is used to detect the detection voltage and a trigger voltage (V TRIG ) generates a test result (S DET The transmission circuit 140 is used to send a power failure warning (S) when the detection result indicates that the detection voltage is lower than the trigger voltage. WARN ) (e.g., a known or self-defined power failure alarm packet (dying gasp packet)) to a remote device (e.g., an optical line terminal (OLT)), wherein the remote device and the power failure detection device 100 are two separate devices. As described above, since the output voltage is lower than the input voltage, the detection voltage can quickly reflect the drop of the input voltage according to the drop of the output voltage, so as to send the power failure warning in time.

[0017] Figure 2 show Figure 1An implementation example of the power failure detection device 100 is shown. In this implementation example, the rated voltage of the input voltage is 12 volts (12V) with an error of 5%; the trigger voltage is 1.25V; and the release trigger voltage as a reference for stopping sending the power failure warning is 1.55V. The buck circuit 110 includes a Zener diode 112; the breakdown voltage of the Zener diode 112 is 9.1V with an error of 2%; the temperature error of the Zener diode 112 is 0.007V / ℃; as described above, the output voltage is equal to the input voltage minus the breakdown voltage (i.e., 12V-9.1V). The detection voltage generating circuit 120 includes a first resistor 122, a second resistor 124, and a node 126. The node 126 is coupled between the first resistor 122 and the second resistor 124. The nominal resistance of the first resistor 122 is 49.9 ohms, and the error is not taken into account. The nominal resistance of the second resistor 124 is 430 ohms, and the error is not taken into account. The voltage of the node 126 is the detection voltage. The detection circuit 130 includes a comparator 132 for converting the detection voltage (V DET ) and the trigger voltage (V TRIG ) to generate the test result (S DET ); when the detection voltage is higher than the trigger voltage, the detection result is a first detection result (e.g., 0), and the power failure warning is not triggered at this time; when the detection voltage is lower than the trigger voltage, the detection result is a second detection result (e.g., 1), and the power failure warning is triggered at this time. The transmission circuit 140 includes a wired network circuit 142 for wired network communication; the wired network circuit 142 is used to generate a wired network data packet as the power failure warning according to the second detection result, and send the wired network data packet to the remote device.

[0018] See also Figure 2 When the power supply is normal, without considering the above errors and temperature changes, the detection voltage is calculated as shown below:

[0019]

[0020] From the above formula, we can know that the detection voltage is higher than the trigger voltage (i.e.: 1.25V) and higher than the release trigger voltage (i.e.: 1.55V), so it will not cause false triggering and can stop sending the power failure alarm when the power is restored. When the power supply is normal, considering the above errors and the temperature rise of 50℃, the minimum value of the detection voltage (i.e.: the value of the detection voltage in the worst case) is as shown in the following formula:

[0021]

[0022] As can be seen from the above formula, in the worst case, the detection voltage is still higher than the trigger voltage and still higher than the release trigger voltage, so it will not cause false triggering, and the power failure alarm can be stopped when the power is restored. When the power is off, without considering the above errors and temperature changes, the input voltage drops; when the input voltage drops to 10.5V, the detection voltage is equal to 1.254V, which is close to the trigger voltage (that is, 1.25V); therefore, as long as the input voltage continues to drop, the detection result will change from the first detection result to the second detection result, and the power failure warning will be triggered.

[0023] Figure 3 show Figure 1 Another implementation example of the power failure detection device 100. In addition to the step-down circuit 110, Figure 3 An implementation example with Figure 2 The implementation example is the same as . Figure 3 In the figure, the step-down circuit 110 includes thirteen diodes 114 connected in series (not all are shown in the figure), wherein the conduction voltage of each diode 114 is 0.7V, and the total conduction voltage of all diodes 114 is 9.1V; the conduction voltage error of each diode 114 is 1%; the temperature error of each diode 114 is As mentioned above, the output voltage is equal to the input voltage minus the total conduction voltage. When the power supply is normal, without considering the above-mentioned errors and temperature changes, Figure 3 The detection voltage is shown as follows:

[0024]

[0025] From the above formula, we can know that the detection voltage is higher than the trigger voltage (i.e.: 1.25V) and higher than the release trigger voltage (i.e.: 1.55V), so it will not cause false triggering and can stop sending the power failure alarm when the power is restored. When the power supply is normal, considering the above errors and the temperature rise of 50℃, the minimum value of the detection voltage (i.e.: the value of the detection voltage in the worst case) is as shown in the following formula:

[0026]

[0027] As can be seen from the above formula, in the worst case, the detection voltage is still higher than the trigger voltage (i.e.: 1.25V) and still higher than the release trigger voltage, so it will not cause false triggering, and the power-off alarm can be stopped when the power is restored. When the power is off, without considering the above-mentioned errors and temperature changes, the input voltage drops; when the input voltage drops to 10.5V, the detection voltage is equal to 1.254V and approaches the trigger voltage (i.e.: 1.25V); therefore, as long as the input voltage continues to drop, the detection result will change from the first detection result to the second detection result, and the power-off warning will be triggered.

[0028] It should be understood that Figure 2-3 The implementation examples are for understanding purposes only and are not intended to limit the implementation of the present invention; other circuits that can achieve equivalent effects can be used instead. Figure 2-3 For example, the detection voltage generating circuit 120 can use the current formed by the output voltage and a reference resistor as a reference current, and then generate a current of a predetermined ratio according to the reference current by means of a current mirror and controlling the transistor size ratio of the current mirror, thereby using the current and a resistor to generate the detection voltage.

[0029] Figure 4 Another embodiment of the power failure detection device disclosed in the present invention is shown. Figure 1 , Figure 4 The power failure detection device 400 further comprises a judgment circuit 410 for generating a trigger signal (S) according to the detection result. TRIG ), wherein when the detection result indicates that the detection voltage is lower than the trigger voltage, the transmission circuit determines whether to send the power-off warning to the remote device according to the trigger signal.

[0030] Figure 5 show Figure 4 An implementation example of a power failure detection device 400. Figure 5 As shown, the judgment circuit 410 includes a logic circuit 412 (eg, a logical AND gate). The logic circuit 412 is used to generate an enable signal (S EN ) generates a first trigger signal (S TRIG_1). In the case where the enable signal is used to enable the power failure detection function of the power failure detection device 400, when the detection result indicates that the detection voltage is lower than the trigger voltage and the first trigger signal is used as the trigger signal, the transmission circuit 140 sends the power failure warning to the remote device according to the first trigger signal. In the case where the enable signal is used to disable the power failure detection function of the power failure detection device 400, no matter what the detection result is, the transmission circuit 140 does not send the power failure warning to the remote device. An embodiment of the enable signal is a software setting signal, and its default level is 1, which is used to enable the power failure detection function of the power failure detection device 400.

[0031] Figure 6 show Figure 4 Another implementation example of the power failure detection device 400. Figure 5 The judgment circuit 410 further includes another logic circuit 414 (eg, a logical OR gate) for determining whether the first trigger signal and a second trigger signal (S TRIG_2 ) generates the trigger signal, wherein the second trigger signal is a setting signal (e.g., a software setting signal in response to the user interrupting the network connection). In the case where the aforementioned enable signal is used to enable the power failure detection function, when the detection result indicates that the detection voltage is lower than the trigger voltage and the first trigger signal is used as the trigger signal, the transmission circuit 140 sends the power failure warning to the remote device according to the first trigger signal; when the second trigger signal is used as the trigger signal, regardless of the detection result, the transmission circuit 140 sends the power failure warning to the remote device according to the second trigger signal.

[0032] Figure 7 An embodiment of the power failure detection method disclosed in the present invention includes the following steps:

[0033] Step S710: using a buck circuit to generate an output voltage according to an input voltage, wherein the output voltage is lower than the input voltage, and the buck circuit is at least one active element, or includes the at least one active element;

[0034] Step S720: generating a detection voltage according to the output voltage;

[0035] Step S730: generating a detection result according to the detection voltage and the trigger voltage; and

[0036] Step S740: When the detection result indicates that the detection voltage is lower than the trigger voltage, a power failure warning is sent.

[0037] Since those skilled in the art can refer to Figure 1-6 The description of the embodiments is to understand Figure 7The details and variations of the embodiments, repetitive and redundant descriptions are omitted here.

[0038] Please note that, under the premise of being implementable, technicians in this technical field may selectively implement some or all of the technical features in any of the aforementioned embodiments, or selectively implement a combination of some or all of the technical features in multiple embodiments, so as to increase the flexibility of the implementation of the present invention.

[0039] In summary, compared with the conventional solution, the present invention can increase the holding time of the power failure alarm function, so as to ensure that the client device can successfully send a power failure warning without using an additional capacitor or a large capacitor.

[0040] Although the embodiments of the present invention are described above, these embodiments are not intended to limit the present invention. Those skilled in the art may make changes to the technical features of the present invention based on the explicit or implicit contents of the present invention. All these changes may fall within the scope of patent protection required by the present invention. In other words, the scope of patent protection of the present invention shall be subject to that defined in the claims of the present disclosure.

[0041]

Explanation of symbols

[0042] 100: Power failure detection device

[0043] 110: Buck circuit

[0044] 120: Detection voltage generating circuit

[0045] 130: Detection circuit

[0046] 140: Transmission circuit

[0047] V IN :Input voltage

[0048] V OUT :Output voltage

[0049] GND: low voltage terminal

[0050] V DET : Detection voltage

[0051] V TRIG :Trigger voltage

[0052] S DET :Test results

[0053] S WARN :Power outage warning

[0054] 112: Zener diode

[0055] 122: First resistor

[0056] 124: Second resistor

[0057] 126: Node

[0058] 132: Comparator

[0059] 142: Wired network circuit

[0060] 114:Diode

[0061] 400: Power failure detection device

[0062] 410: Judgment circuit

[0063] S TRIG :Trigger signal

[0064] 412:Logic Circuit

[0065] S EN : Enable signal

[0066] S TRIG_1 :First trigger signal

[0067] 414:Logic Circuit

[0068] S TRIG_2 : Second trigger signal

[0069] S710~S740: Steps

Claims

1. A power failure detection device, comprising: A step-down circuit, used for generating an output voltage according to an input voltage, wherein the output voltage is lower than the input voltage, the step-down circuit is at least one active element, or includes the at least one active element, the at least one active element is at least one diode, and the at least one diode includes a plurality of diodes arranged in series in the same direction; a detection voltage generating circuit, coupled between the step-down circuit and the low voltage terminal, for generating a detection voltage according to the output voltage, wherein the detection voltage is lower than the output voltage and higher than the voltage of the low voltage terminal; A detection circuit, used for generating a detection result according to the detection voltage and the trigger voltage; as well as a transmission circuit, configured to send a power failure warning to a remote device when the detection result indicates that the detection voltage is lower than the trigger voltage, The detection circuit includes a comparator, and the comparator is used to compare the detection voltage with the trigger voltage to generate the detection result. The power failure detection device further comprises: The judgment circuit is used to generate a trigger signal according to the detection result, wherein when the detection result indicates that the detection voltage is lower than the trigger voltage, the transmission circuit determines whether to send the power failure warning to the remote device according to the trigger signal. 2 . The power failure detection device according to claim 1 , wherein the at least one diode is at least one Zener diode.

3. The power failure detection device according to claim 1, wherein the judgment circuit comprises: A first logic circuit is used to generate a first trigger signal according to the detection result and an enable signal, wherein when the enable signal is used to enable the power off detection function of the power off detection device, when the detection result indicates that the detection voltage is lower than the trigger voltage and the first trigger signal is used as the trigger signal, the transmission circuit sends the power off warning to the remote device according to the first trigger signal.

4. The power failure detection device according to claim 3, wherein the judgment circuit further comprises: The second logic circuit is used to generate the trigger signal according to the first trigger signal and the second trigger signal, wherein the second trigger signal is a software setting signal. When the second trigger signal is used as the trigger signal, regardless of the first trigger signal, the transmission circuit sends the power off warning to the remote device according to the second trigger signal. 5 . The power failure detection device according to claim 1 , wherein the transmission circuit is used for wired network communication, and the power failure warning is a network data packet.

6. A power failure detection method, comprising: Using a step-down circuit to generate an output voltage according to an input voltage, wherein the output voltage is lower than the input voltage, the step-down circuit is at least one active element or includes the at least one active element, the at least one active element is at least one diode, and the at least one diode includes a plurality of diodes arranged in series in the same direction; generating a detection voltage according to the output voltage; Generate a detection result according to the detection voltage and the trigger voltage; generating a trigger signal according to the detection result; as well as When the detection result indicates that the detection voltage is lower than the trigger voltage, a power failure warning is sent, The generating of the detection result according to the detection voltage and the trigger voltage comprises: comparing the detection voltage with the trigger voltage to generate the detection result, The power failure detection method further comprises: When the detection result indicates that the detection voltage is lower than the trigger voltage, whether to send the power-off warning is determined according to the trigger signal.

Images