TW202105429A - Circuit including electrical fault indicator and method of fuse status diagnostic - Google Patents

Abstract

Various embodiments are generally directed to ensuring an electrical fault indicator, such as a light-emitting diode (LED), remains active in the event of an electrical fault in a circuit, even if a load fault, such as an excessive load, a load short circuit, or a load open circuit occurs. Various circuit configurations are provided to achieve this effect, including but not limited to a circuit that includes: a fuse connected between two circuit points, one or more conduction paths sharing a common node with the fuse, a first circuit element sharing the common node with the fuse, and an electrical fault indicator, sharing either i) the common node with the fuse and the first circuit element or ii) another common node with the first circuit element that is distinct from the common node between the fuse and the first circuit element.

Description

Fuse status diagnosis with and without load operable

The present invention is generally related to the field of circuit protection devices, and more specifically, it is related to a technology that enables an electrical fault indicator to maintain operability when an electrical fault occurs.

Fuses are often used in circuit protection devices, usually installed between the power supply and the components to be protected in the circuit. A conventional fuse includes a pair of conductive terminals connected to each other via a fusible element, wherein the fusible element extends through an electrically insulating housing. When a fault event such as overcurrent occurs, the fusible element melts and breaks, or is separated in other ways, thereby interrupting the current passing between the power supply and the component to be protected. In this way, the fuse prevents the overcurrent state from persisting, thereby preventing or reducing electrical damage to the power supply or components to be protected.

Observers, such as repair technicians, need to visually judge that the fusible element has melted when the fusible element of the fuse is melted due to overcurrent conditions or other failures. To this end, an electrical fault indicator, such as a light emitting diode (LED), can be connected to a circuit protected by a fuse, and configured to activate (that is, emit light) when the fusible element of the fuse in the circuit melts. Therefore, the electrical fault indicator must provide reliable operation to ensure that the observer correctly judges the state of the circuit protected by the fuse.

The improvements provided here may help meet these and other considerations.

This content of the invention introduces the concept of the invention in a simplified form, and the relevant details will be provided in the following embodiments. The purpose of this paragraph of the content of the invention is not to specify the main or essential features of the subject of the invention, nor is it to define the scope of the subject of the invention.

One aspect of the present invention includes a circuit that can maintain the normal operation of the electrical fault device without being affected by the load status. The circuit includes: a fuse connected between two circuit points between a voltage source and a load, one or more conduction paths that share at least one common node with the fuse, and a first circuit that shares the at least one common node with the fuse Element, and an electrical fault indicator, the electrical fault indicator is i) sharing the at least one common node with the fuse and the first circuit element or ii) sharing another common node with the first circuit element, the other common The node is different from the at least one common node between the fuse and the first circuit element, wherein when the fuse is open in response to an electrical fault, sufficient current passes through the electrical fault indicator to inform an observer of the electrical fault It has occurred, and where the connection of the common node to the first circuit element creates a separate discharge loop for the current, which is different from any path connection terminating in the load.

In various embodiments, the circuit may be configured such that the electrical fault indicator shares the at least one common node with the fuse and the first circuit element, wherein the first circuit element is a first resistor, and the one or The multiple conductive paths are formed by a single conductive path, which includes the electrical fault indicator connected in series with the second resistor, and wherein the single conductive path is connected in parallel with the fuse. In various embodiments, when i) the load is disconnected from the circuit due to a load fault condition, and ii) the fuse is open due to an electrical fault, the first resistor, the second resistor and the electrical The fault indicator is in series. In various embodiments, the electrical fault indicator is a light emitting diode (LED), and the electrical fault and the load fault are different from each other.

In various embodiments, the circuit may be configured such that the electrical fault indicator and the first circuit element share the other common node, wherein the first circuit element is a first diode, and the one or more conductive One of the paths includes a second diode in series with the gate electrode of a transistor, and the circuit further includes a resistor in series with the electrical fault indicator and the drain or source of the transistor. In various embodiments, the electrical fault indicator is a light emitting diode (LED), and the electrical fault and the load fault are different from each other.

In various embodiments, the circuit may be configured such that: the electrical fault indicator and the first circuit element share the other common node, wherein the first circuit element is a first resistor, and wherein the one or more conductive paths One of them includes a second resistor in series with the gate electrode of a transistor, and the circuit further includes: a third resistor in series with the electrical fault indicator and the drain or source of the transistor. In various embodiments, the electrical fault indicator is a light emitting diode (LED), and the electrical fault and the load fault are different from each other.

In various embodiments, the circuit may be configured such that: the electrical fault indicator and the first circuit element share the other common node, wherein the first circuit element is a first resistor, and wherein the one or more conductive paths One of them includes a second resistor in series with the gate electrode of a transistor, and the circuit further includes: a third resistor in series with the electrical fault indicator and the drain or source of the transistor. In various embodiments, the electrical fault indicator is a light emitting diode (LED), and the electrical fault and the load fault are different from each other.

In various embodiments, the circuit may be configured such that the electrical fault indicator and the first circuit element share the other common node, wherein the electrical fault indicator and the first circuit element share the other common node, wherein The first circuit element is a first resistor, wherein the one or more conductive paths include i) a first conductive path including a second resistor, ii) a second conductive path including a diode, and iii) a circuit The third conduction path of the crystal, where the second resistor, where the fuse and the diode are connected in parallel, and where the circuit further includes: a series connection with the electrical fault indicator and the drain or source of the transistor The third resistor. In various embodiments, the common node is the connection point of the diode, the fuse and the second resistor, and another common node includes the fuse, the second resistor, and the diode Another contact point connected with the source or drain of the transistor. In various embodiments, the diode is a Zener diode, and the transistor is a field effect transistor (FET).

Another aspect of the present invention includes a circuit connection method that allows the electrical fault device to operate normally without being affected by the load status. The method includes: providing a fuse connected between two points between a voltage source and a load in the circuit, and connecting a fuse, a first circuit element, an electrical fault indicator, and one or more conduction paths of the circuit to a common node , So that when the fuse is open in response to an electrical fault, sufficient current can pass through the electrical fault indicator to inform the user that the electrical fault has occurred, and the connection of the common node to the first circuit element is The current creates a separate discharge circuit, which is different from any path connection that terminates in the load. In various embodiments, the first circuit element is a first resistor, the one or more conductive paths include a single conductive path, including the electrical fault indicator in series with the second resistor, the single conductive path and The fuse is connected in parallel, and when i) the load is disconnected from the circuit due to a load fault condition and ii) the fuse is open due to an electrical fault, the first resistor, the second resistor and the electrical The fault indicator is in series. In various embodiments, the electrical fault indicator is a light emitting diode (LED), and the electrical fault and the load fault are different from each other.

Another aspect of the present invention includes another circuit that can maintain the normal operation of the electrical fault device without being affected by the load status. The circuit includes: a fuse connected between two circuit points, wherein the two circuit points are located between a voltage source and a load; at least one conduction path including a switch, wherein the switch is connected in series with a resistor and an electrical fault indicator, And the switch and the fuse share a node; and a relay device connected to the fuse via another node; when the fuse operates under normal conditions, the relay device creates an open circuit based on the switch relative to the at least one conduction path. One state is energized, causing the electrical fault indicator to enter the off state, and when the fuse is blown in response to an electrical fault, the relay device is powered off according to the second state, causing the electrical fault indicator to enter the on state and creating a separate discharge for the circuit current Circuit, where the discharge circuit is different from any path connection that terminates in the load.

On the whole, the various circuit embodiments provided by the present invention are used to maintain the operability of an electrical fault indicator, such as a light emitting diode (LED), whose purpose is to let the observer know Fuse tripping, for example, a situation where the fusible element in the fuse melts, blows, or is disconnected in other ways due to an electrical fault in the circuit connected to the fuse. In various embodiments of the present invention, even if the load attached to the circuit fails, such as excessive resistance or impedance and/or short circuit conditions, the voltage source can still supply current to the electrical fault indicator in the circuit. In the prior art, the electrical fault indicator can maintain normal operation only when the load meets appropriate conditions, and various embodiments of the present invention provide an independent discharge path in the circuit loop provided with the electrical fault indicator, thereby Ensure that even if a load fault condition occurs, it does not affect the normal operation of the electrical fault indicator.

The following describes various circuit diagrams and discusses energy, current, voltage, conduction paths, and circuit elements. Some conduction paths in the circuit diagram may not be marked and are not described here, and some currents, voltages, circuit elements or other circuit values may not be described or marked. However, this is not intended to limit the various circuit configurations and embodiments of the present invention. Provide inherent functions or features. Specific voltage sources, current values, and circuit components are indicated in the figure, but depending on the values selected for labeling the circuit components, some other currents or voltages present in the circuit may not be labeled, but this is not intended to affect the present invention in the figure. The illustrated embodiment constitutes a limitation, and its purpose is only to provide a brief description of the various embodiments of the present invention.

The various circuits and embodiments provided by the present invention can be implemented in various applications, including a fuse box used in automobiles to prevent and/or detect electrical faults related to automobile operation. It also provides a method for automobile users or repairs, etc. The technician who inspects the vehicle for various purposes learns the method of the malfunction.

In the circuit diagram of FIG. 1A, the circuit 100A is used to maintain the operability of the electrical fault indicator 12 when the fuse 10a is tripped or blown due to an electrical fault. In various embodiments, the electrical fault indicator 12 may be a light emitting diode (LED). In the figure, the fuse 10a of the circuit 100A is in a normal non-tripped or non-blown state. As shown in the figure, the fuse 10a (and the electrical fault indicator 12) is located between two points P1 and P2 in the circuit, where P1 corresponds to the connection with the positive terminal of the voltage source V1, and P2 is the pair of the first resistor R1 The connection point with load L1. As shown in the figure, the voltage source is a DC source, but in other embodiments of the present invention, the voltage may be an AC source.

In various embodiments, as shown in the figure, P1 and P2 correspond to nodes N1 and N2, respectively, and related details will be described in detail below. The conductive path 20 to which the electrical fault indicator 12 belongs starts from the positive terminal of the voltage source V1 and includes a second resistor R2 connected in series with the electrical fault indicator 12. The fuse 10a is in a normal operating state and belongs to a conductive path 15. The conduction path 15 and the conduction path 20 are connected at nodes N2 and N1, which correspond to points P1 and P2 in various embodiments. The connection of the conductive paths 15 and 20 allows the series connection of R2 and the electrical fault indicator 12 to be connected in parallel with the fuse 10a. The conductive paths 15 and 20 are connected to a node N2, which provides a common connection node for the electrical fault indicator 12, the fuse 10a, the resistor R1 and the load L1. (In various embodiments, depending on the application, the resistor R2 can be omitted and the terminal of the voltage source V1 can be directly connected to the electrical fault indicator 12). The resistor R1 is connected from the node N1 to the node N3, and can provide a separate discharge path or loop to close the circuit when a load failure occurs (as will be described in detail with reference to FIG. 1B). In various embodiments, the node N3 may correspond to the ground.

As shown in FIG. 1A, since the fuse 10a operates under normal conditions, it acts like a circuit element with very small or zero impedance and/or resistance, such as a short circuit, so the current I2 will be a very small value or zero. Accordingly, most or all of the current generated by the voltage source V1 can flow through the conductive path 15 and can be shunted between the load L1 and the resistor R1. The current I1 refers to the part of the current that can flow to the load L1, and the current flowing through the resistor R1 is not clearly shown in the figure. Current distribution is a design choice and depends on the value of resistor R1 and load L1. Depending on the application, the value can be selected to ensure that the circuit 100A operates normally during normal (and near abnormal) operability or during operation.

FIG. 1B shows that the circuit 100A becomes the circuit 100B after an electrical failure and a load failure occur. In various embodiments, load faults and electrical faults may be different, and in various embodiments, load faults and electrical faults may be the same. As shown in the figure, a fault in the circuit 100A, such as overcurrent or other electrical faults, causes the fuse 10a to trip or blow and become a trip or blow fuse 10b. Under this condition, the fuse 10b can form a circuit element with extremely high resistance or impedance, such as an open circuit, so that most or all of the current associated with the voltage source V1 travels through the conduction path 20. Accordingly, the value of the current I2 may be greater than the state of the circuit 100A during normal operation.

The current I2 can flow through the resistor R2, and the voltage drop caused by the resistor R2 can activate the electrical fault indicator 12. For example, in the embodiment where the electrical fault indicator 12 is an LED, the electrical fault indicator 12 can be positive by applying To achieve this goal by biasing the voltage. The specific values and configurations of the resistor R2 and the electrical fault indicator 12, such as the threshold voltage of the LED and/or the resistance value of the resistor R2, are design choices and vary depending on the desired application. In various embodiments, the resistor R2 can be omitted, and the terminal of the voltage source V1 can be directly connected to the electrical fault indicator 12. In various embodiments, the value of the resistor R2 can be selected to ensure that no excessive current flows through the electrical fault indicator 12, for example, when the normal operation of the circuit 100A requires a larger voltage source V1.

As described above, tripping or blowing the fuse 10b may cause most of the current to travel through the conductive path 20. According to this, the current I2 can flow through the resistor R2 and the electrical fault indicator 12. At this time, the electrical fault indicator 12 is in an active state. If the electrical fault indicator 12 is an LED, it can be forward biased and can emit light. An observer, such as a technician, learns that an electrical fault has occurred.

In various embodiments, if a load failure occurs, such as a load L1 with an excessively high resistance or an open circuit LF 1a or a load L1 with a load short circuit LF 1b, the resistor R1 provides a separate discharge path or loop to the node N3. The area 50 represents the area where the circuit has a load failure, but other areas may also be related to the load failure described in the present invention. In various embodiments, with respect to FIG. 1B and with respect to any other embodiments and related drawings, the term "load fault" may indicate a fault that the load actually experiences that prevents it from providing a set operation. This fault may be different from causing the fuse 10b to trip. Or fusing electrical failure. In other embodiments, the term "load failure" can mean that the load is in normal operating conditions and conditions, although it is not affected by the electrical fault that caused the fuse 10a to blow or trip and cause the electrical fault indicator 12 to activate. The fuse 10a trips or blows into a discharge path that provides current when the fuse 10b trips or blows. In either case, the resistor R1 in the circuit can provide a discharge path through the conductive path 22 to the node N3, so that the electrical fault indicator 12 can still operate normally when the load cannot provide a discharge path. In various embodiments, if there is no resistor R1 (or other suitable circuit elements to provide a path), the electrical fault indicator 12 may not operate when a load failure such as LF 1a or LF 1b occurs and the fuse 10b trips or blows.

Accordingly, the configuration of the circuit 100A includes the resistor R1, so that the electrical fault indicator 12 can still operate normally when the load condition is improper. The resistor value of the resistor R1 can be adjusted or selected according to specific application requirements, for example, according to the specific operation requirements of the circuit 100A, and the requirements for the normal operation of the electrical fault indicator 12 are taken into consideration.

2A shows a circuit diagram of another circuit 200A, which is used to maintain the operability of the electrical fault indicator 12 when the fuse 10a is tripped or blown due to an electrical fault. First, it will be explained that the circuit 200A includes a MOSFET transistor Q1, and more specifically, a P-FET transistor Q1. Depending on the application, other MOSFETs, such as N-FETs, or other transistor devices, such as PNP, BJT, etc., can be used to replace the entire FET device, and other parts of the circuit 200A can be appropriately adjusted according to the teachings of the present invention to ensure related normal functions .

In various embodiments, the circuit 200A includes a fuse 10a connected between two points P1 and P2, wherein the fuse 10a is located between two points P1 and P2 of the circuit, and P1 corresponds to the connection with the positive terminal of the voltage source V1, and P2 is the connection point between the first resistor R1 and the load L1. In various embodiments, as shown in the figure, P1 and P2 correspond to nodes N1 and N2, respectively, and related details will be described in detail below. As shown in the figure, the voltage source V1 is a DC source, but in other embodiments, the voltage may be an AC source.

In various embodiments, as shown in the figure, P1 and P2 correspond to nodes N1 and N2, respectively, and related details will be described in detail below. Fuse 10a belongs to conduction path 30 and is connected to conduction paths 35, 37, and 40 at node N2, conduction path 35, 37, 40, 23 and load L1 are connected at node N1, node N1 is fuse 10a, resistor R3, Zener two The pole body Z1 and the load L1 provide a common connection node. The conductive path 35 includes a resistor R3 connected in parallel with the Zener diode Z1, wherein the Zener diode Z1 belongs to the conductive path 37. In various embodiments, the circuit 200A (and via the extension circuit 200B described below) may not use the conductive path 37 and the Zener diode Z1. In various embodiments, the circuit 200A (and via the extension circuit 200B described below) has a conductive path 35 of the resistor R3. In various embodiments, the circuit 200A (and via the extension circuit 200B described below) may not have the conductive path 37 and the conductive path 35.

A P-FET transistor Q1 is associated with the conduction path 40, as shown in the figure, where the source of the transistor Q1 is connected to the resistor R3 at the node N2, to the fuse 10a and to the Zener diode Z1. A gate of Q1 belongs to the conduction path 40 and is connected to the Zener diode Z1, resistor R3, resistor R1, fuse 10a, and load L1 at node N1, and the drain of transistor Q1 is connected to the conduction Path 27 (detailed here). The conduction path 23 includes a resistor R1 and is connected to the Zener diode Z1, the resistor R3, and the fuse 10a at the node N1. When a load failure occurs at L1, the circuit element of FIG. 2A is connected at the nodes N1 and N3 to provide discharge Loop. In various embodiments, node N3 corresponds to ground.

In various embodiments, as described above, the transistor Q1 can be a different type of FET, such as an N-FET, in which the source/drain, gate and other circuit parts can be modified according to the teachings of the present invention to ensure The operability of the circuit 200A. In various embodiments, the transistor Q1 may be a non-FET device, in which circuit modifications can be made in accordance with the teachings of the present invention to ensure the operability of the circuit 200A.

The conduction path 27 starts from the drain of the transistor Q1 and the conduction path 27 includes a resistor R2 connected in series with the electrical fault indicator 12, where the electrical fault indicator 12 is, for example, an LED and is connected at node N3, which is connected to the load L1 And the common connection shared by resistor R1.

Figure 2A shows the normal operation of the circuit 200A, where the fuse 10a is intact and not tripped. Accordingly, the current I2 may be extremely small or zero, because most or all of the current related to the voltage source V1 will flow through the fuse 10a, which is in a low resistance or impedance state at this time, and the current I1 is the current that will flow to the load L1 Part, the rest of the current (not shown) can flow through the resistor R1, for example, shunt between the load L1 and the resistor R1. In various embodiments, if the circuit 200A includes one or both of the Zener diode Z1 and the resistor R3, the transistor Q1 can be protected from the voltage and/or current surge of the circuit. This point will be referred to below Figure 2B details.

FIG. 2B shows that the circuit 200A becomes the circuit 200B after the occurrence of an electrical fault and a load fault. In various embodiments, the load fault and the electrical fault may be different, while in other embodiments, the load fault and the electrical fault may be the same. As shown in the figure, a fault in the circuit 200A, such as overcurrent or other electrical faults, causes the fuse 10a to trip or blow and become a trip or blow fuse 10b. Under this condition, the fuse 10b can function as a circuit element with extremely high resistance or impedance, such as an open circuit, and most or all of the current associated with the voltage source V1 travels through other conductive paths other than the conductive path 30, such as the conductive path 35. Accordingly, the value of the current I2 is higher than that of the circuit 200A during normal operation.

A part of the current I2 can flow through the resistor R3 and the resistor R1, for example, the voltage input V1 (and the associated current I2) is shunted between the resistor R3 and the resistor R1. Resistor R1 is related to the gate of transistor Q1, and the resistance of resistor R3 is related to the source of transistor Q1. When the difference between the gate voltage and the source voltage is smaller than that of transistor Q1 (as shown in the figure) When the threshold voltage associated with the P-FET shown in the figure, transistor Q1 is activated. After the transistor Q1 is activated, the current flows from the drain of the transistor Q1 through the resistor R2 and extends to the electrical fault indicator 12, and the electrical fault indicator 12 is activated. For example, if the electrical fault indicator 12 is an LED, it can be positive It is biased and can emit light. If the difference between the gate voltage and the source is greater than the threshold voltage of the transistor Q1, including during the normal operation of the circuit 200A, the transistor Q1 will not function, and the electrical fault indicator 12 will not function.

In various embodiments, the values of the resistors R1 and R3 can be selected to achieve various purposes of the application in which the circuit 200B is used, including the consideration of the threshold voltage associated with the transistor Q1. If transistor devices with different thresholds and/or start-up characteristics are used, the values of V1 and resistors R2 and R1 (and other circuit components) can also be adjusted.

In various embodiments, the function of the resistor R3 is to protect the transistor Q1 from shunting the input voltage V1 and currents related to other circuit elements, and thus prevent the transistor Q1 from being too high at the voltage V1 (or another overvoltage or overvoltage). Current condition occurs). In the same way, the Zener diode Z1 can generate a bias when the source and/or gate (depending on the configuration used) voltage is too high, and form an alternative path for power supply to protect the transistor Q1 from overvoltage Or over-current conditions can prevent the transistor Q1 from being damaged. The characteristics of the Zener diode Z1, including the threshold voltage, can be adjusted according to the required application and/or other values of the circuit elements in the circuit 200A.

In various embodiments, the transistor Q1 is provided in the circuit to help improve the control and stability of the electrical fault indicator 12, which is more prone to specific conditions such as sudden voltage changes than other applications. value. In various embodiments, at least for the reasons described here, including protecting the transistor Q1 from overvoltage or overcurrent, the provision of one or more Zener diodes Z1 and resistor R3 in the circuit helps Further enhance stabilization.

In various embodiments, if a load failure occurs, such as a load L1 with an excessively high resistance or an open circuit LF 1a or a load L1 with a load short circuit LF 1b, the resistor R1 provides a separate discharge path or loop to the node N3. The area 50 represents the area where the circuit has a load failure, but other areas may also be related to the load failure described in the present invention. The resistor R1 can provide a discharge path through the conductive path 23 to the node N3 to ensure that the electrical fault indicator 12 can operate normally. If there is no resistor R1 (or other suitable circuit elements to provide a path), the electrical fault indicator 12 may not work when a load failure such as LF 1a or LF 1b occurs and the fuse 10b trips or blows.

Accordingly, the configuration of the circuit 200A includes the resistor R1, so that the electrical fault indicator 12 can still operate normally when the load condition is improper. The resistor value of the resistor R1 can be adjusted or selected according to specific application requirements, for example, according to the specific operating requirements of the circuit 200A, and the requirements for the normal operation of the electrical fault indicator 12 are taken into consideration.

FIG. 3A shows a circuit diagram of another circuit 300A, which is used to maintain the operability of the electrical fault indicator 12 when the fuse 10a is tripped or blown due to an electrical fault. First, it will be explained that the circuit 300A includes a MOSFET transistor Q1, and more specifically, a P-FET transistor Q1. Depending on the application, other MOSFETs, such as N-FETs, or other transistor devices, such as PNP, BJT, etc., can be used to replace the entire FET device, and other parts of the circuit 300A can be appropriately adjusted according to the teachings of the present invention to ensure related normal functions .

In various embodiments, the circuit 300A includes a fuse 10a connected between two points P1 and P2, wherein the fuse 10a is located between two points P1 and P2 of the circuit, and P1 corresponds to the connection with the positive terminal of the voltage source V1, and P2 is the connection point between the first resistor R1 and the load L1. In various embodiments, as shown in the figure, P1 and P2 correspond to nodes N1 and N2, respectively, and related details will be described in detail below. As shown in the figure, the voltage source V1 is a DC source, but in other embodiments, the voltage may be an AC source.

In various embodiments, as shown in the figure, P1 and P2 correspond to nodes N1 and N2, respectively, and related details will be described in detail below. The fuse 10a belongs to the conduction path 42 and is connected to the source of the transistor Q1 at N2, and the conduction path 42 is connected to the conduction paths 45 and 49 at the node N1, including the fuse 10a connected to the anode and the diode of the diode D2 The cathode of the body D1, and a common connection point between the fuse 10a and the diode D1 to the load L1 is provided. In various embodiments, although not shown in the figure, the diode D1 and the diode D2 may each be replaced by one or more resistors or resistance elements.

A P-FET transistor Q1 is associated with the conduction path 42, as shown in the figure, where the source of the transistor Q1 is connected to the resistor R3 and the Zener diode Z1 at node N2, and the gate Q1 of the transistor belongs to The conductive path 45 is connected to the cathode of the diode D2, and a node on the diode D2 also belonging to the conductive path 45 is connected to the cathode of the diode D1 and the load L1 at the node N1. The conduction path 49 includes a diode D1, wherein the diode D1 is connected to the node N1 and the node N3 along the conduction path 49, and when a load failure occurs in L1, the circuit element of FIG. 3A is connected to the nodes N1 and N3 to provide discharge Loop, where in various embodiments, node N3 corresponds to ground. The conduction path 47 starts from the drain of the transistor Q1 and the conduction path 47 includes a resistor R1 connected in series with an electrical fault indicator 12 such as an LED, wherein the electrical fault indicator 12 is connected at node N3, which is shared with the load L1 And the common connection of diode D1.

In various embodiments, as described above, the transistor Q1 can be a different type of FET, such as an N-FET, in which the source/drain, gate and other circuit parts can be modified according to the teachings of the present invention to ensure The operability of the circuit 300A. In various embodiments, the transistor Q1 may be a non-FET device, in which circuit modifications can be made in accordance with the teachings of the present invention to ensure the operability of the circuit 300A.

FIG. 3A shows the normal operating state of the circuit 300A, in which the fuse 10a is intact and not tripped. Accordingly, most or all of the current related to the voltage source V1 can flow through the fuse 10a in a low-resistance or impedance state, and I1 is the part of the current that will flow to the load L1. In various embodiments, the current I1 can represent all, part or most of the current generated by the voltage V1, depending on the setting characteristics of the transistor Q1, the diode D1, the diode D2, the load L1, and other circuit values, such as The value of the voltage V1 related to the threshold voltage of the transistor Q1, the resistance of the diode D1, the diode D2, and the load L1. In various embodiments, under normal operating conditions, such as when the fuse 10 is not tripped, due to the configuration of the diode D1 and the diode D2, the voltage at the gate of the transistor Q1 is equal to the voltage at the source of the transistor Q1 , And the transistor Q1 is off, because the threshold condition of the (P-FET) transistor Q1 is set to that the difference between the gate voltage and the source voltage of the transistor Q1 must be less than the threshold voltage before it can function, so the electrical fault indication The device 12 is also in a closed state.

FIG. 3B shows that the circuit 300A becomes the circuit 300B after an electrical failure and a load failure occur. In various embodiments, electrical faults and load faults may be different, and in various embodiments, load faults and electrical faults may be the same. As shown in the figure, a fault in the circuit 300A, such as overcurrent or other electrical faults, causes the fuse 10a to trip or blow and become a trip or blow fuse 10b, and the area 50 is an area including one or more load faults, such as Loads with too high resistance or open LF 1a and/or loads with short-circuit LF 1b. In response to electrical faults, (as mentioned above, it may be different from load faults) fuse 10b can function as a circuit element with extremely high resistance or impedance, such as an open circuit. Accordingly, the current cannot pass through the tripped fuse 10b.

When the fuse 10b is tripped, blown, or otherwise in an open state, the diode D1 can pull down (P-FET) the voltage of the gate of the transistor Q1, so that the gate voltage of the transistor Q1 is between the gate voltage and the source voltage. The difference is less than the threshold voltage of transistor Q1, then transistor Q1 is in an active state. Thereafter, in various embodiments, current can be supplied to the resistor R1 and the electrical fault indicator 12 at the drain of the transistor Q1. For example, if the electrical fault indicator 12 is an LED, it can be forward biased and can emit light. , Start the electrical fault indicator 12. If the difference between the gate and source voltages is greater than the threshold voltage of the transistor Q1, including during the normal operation of the circuit 300A, the transistor Q1 will not function, and the electrical fault indicator 12 will not function.

In various embodiments, the characteristics of the diodes D1 and D2, such as the threshold voltage, can be selected to achieve various purposes of the application to which the circuit 300B belongs, including the consideration of the threshold voltage related to the transistor Q1. If transistor devices with different thresholds and/or start-up characteristics are used, the value of V1 and the characteristics of the diodes D1 and D2 (and other circuit components) can also be adjusted. In various embodiments, the resistor can replace the diode D1 and the diode D2 with an appropriate resistance value selected to achieve the bias voltage required by various components, such as the transistor Q1, and depends on where the circuit 300A and the circuit 300B are located. Other requirements of the application.

In various embodiments, if a load fault occurs in the load L1, such as an excessive resistance or an open circuit LF 1a or a load short circuit LF 1b in the load L1, the diode D1 provides a separate discharge path or mechanism to completely communicate with the nodes N1, N2, and N3. Related circuit. The area 50 represents the area where the circuit has a load failure, although other areas may also be related to the load failure described in the present invention. If there is no diode D1 (other suitable circuit elements provide a path), when a load failure, such as LF 1a or LF 1b, occurs and the fuse 10b trips or blows, the electrical fault indicator 12 may not work.

In various embodiments, the transistor Q1 is provided in the circuit to help improve the control and stability of the electrical fault indicator 12, which is more prone to specific conditions such as sudden voltage changes than other applications. value. In various embodiments, providing one or more diodes D1 and D2 in the circuit can further improve the stability, including by controlling the voltage spikes related to the gate of the transistor Q1. Other reasons that can be thought of.

Accordingly, the configuration of the circuit 300A includes the resistor R1, so that the electrical fault indicator 12 can still operate normally when the load condition is improper. The resistor value of the resistor R1 can be adjusted or selected according to specific application requirements, for example, according to the specific operation requirements of the circuit 300A, and the requirements of the normal operation of the electrical fault indicator 12 are taken into consideration.

4A is a circuit diagram of the circuit 400A, which can maintain the operability of the electrical fault indicator 12 when the fuse 10a is tripped or blown due to an electrical fault. In various embodiments, the electrical fault indicator 12 may be a light emitting diode (LED). In the circuit 400A shown in the figure, the fuse 10a is normally not tripped or not blown. As shown in the figure, the fuse 10a is located between two points of the circuits P1 and P2, where P1 corresponds to the connection with the positive terminal of the voltage source V1, and P2 is the connection point to the first resistor R1 and the load L1. As shown in the figure, the voltage source is a DC source, but in other embodiments, the voltage can also be an AC source.

At least two conductive paths are shown in FIG. 4A, namely a conductive path 52 and a conductive path 55. The conductive path 52 includes a switch S1 connected in series with the resistor R1 and an electrical fault indicator 12, such as an LED. The conductive path 55 includes a relay device K1 for controlling the switch S1. The fuse 10a is connected to the conductive path 52 at N2, and the fuse is connected to the conductive path 55 at the node N1. Both conductive paths terminate at the node N3, and the node N3 corresponds to the ground in various embodiments. The node N1 is a common connection node of the relay device K1, the load L1, and the fuse 10a.

The circuit 400A shows the normal operating state of the circuit 400, in which the fuse 10a operates normally and operates in a low resistance and low impedance state. A part of the current generated by the voltage source V1 (not explicitly shown in the figure) can change the relay device K1, and a part of the current I1 can go to the load L1. During normal operation, the relay device K1 is fully charged and causes the switch S1 to be in an open state, prohibiting the current from going down the conduction path 52 and preventing the electrical fault indicator 12 from starting, and therefore the current I2 can be a minimum or zero.

FIG. 4B shows that the circuit 400A becomes the circuit 400B after an electrical failure and load failure occur. In various embodiments, load faults and electrical faults may be different, and in various embodiments, load faults and electrical faults may be the same. As shown in the figure, a fault in the circuit 400A, such as overcurrent or other electrical faults, causes the fuse 10a to trip or blow and become a trip or blow fuse 10b, and the area 50 represents an area including one or more load faults, for example Loads with excess resistance LF 1a and/or loads with short-circuit LF 1b. In response to electrical faults, (as mentioned above, it may be different from load faults) fuse 10b can function as a circuit element with extremely high resistance or impedance, such as an open circuit. Accordingly, no current or only a very small current can flow through the tripped or blown fuse 10b, and the current I1 may be very small or zero. In the same way, no current or only a very small current can flow through the relay device K1, making it in a discharged state and closing the switch S1. When the switch S1 is closed, the current I2 can be all or most of the current generated by the voltage V1. The voltage drop caused by the resistor R1 will activate the electrical fault indicator 12. For example, if the electrical fault indicator 12 is an LED, It can be forward biased and can emit light. Therefore, regardless of the condition of the load L1 and whether there is a load failure, such as a load with an excess resistance LF 1a or a load with a load short circuit LF 1b, when the fuse 10b is blown or tripped, the switch s1 will connect the conduction path 52 to the circuit The other parts are isolated so that the conduction path 52 is not affected by load conditions, and the electrical fault indicator 12 can be activated.

As with other embodiments described herein, the specific values and configurations of circuit elements 400A and 400B can be adjusted according to design choices and specific application requirements of circuit 400A and/or circuit 400B.

Accordingly, the configuration of the circuit 400A, including the setting of the switch S1 and the relay device K1, is to provide the electrical fault indicator 12 with an independent starting path that is not affected by the load condition by the relay device K1 and the switch S1. Therefore, the electrical fault indicator 12 is in the load It can still operate normally when the condition fails.

As used herein, "embodiment", "implementation", "example" and/or equivalent terms should not be construed as excluding the existence of other embodiments that also include the features.

Although the present invention is described with reference to specific embodiments, various modifications, changes, and changes to the embodiments may be made without departing from the field and scope of the present invention, as defined in the scope of the patent application in this case. Accordingly, the present invention is not limited to the above-mentioned embodiments, but should cover the complete scope defined by the language of the following patent application and its equivalents.

10: Laser system 10a, 10b: fuse 100A, 200A, 200B, 300A, 300B, 400, 400A, 400B: circuit 12: Electrical fault indicator 15, 20, 22, 23, 27, 35, 37, 40, 42, 45, 47, 49, 52, 55: conduction path 50: area D1, D2: Diode I1, I2: current K1: Relay device L1: load LF 1a, LF 1b: Load failure N1, N2, N3: Node P1, P2: point Q1: Transistor R1, R2, R3: resistors S1: switch V1: Voltage source Z1: Zener diode

The circuit diagram of FIG. 1A shows at least one circuit element for maintaining the operability of the electrical fault indicator during a load fault period in at least one embodiment of the present invention. The circuit diagram of FIG. 1B shows one or more characteristics of the circuit of FIG. 1A during load failure in at least one embodiment of the present invention. The circuit diagram of FIG. 2A shows at least one circuit element for maintaining the operability of the electrical fault indicator during a load fault period in at least one embodiment of the present invention. The circuit diagram of FIG. 2B shows one or more characteristics of the circuit of FIG. 2A during load failure in at least one embodiment of the present invention. The circuit diagram of FIG. 3A shows at least one circuit element for maintaining the operability of the electrical fault indicator during a load fault period in at least one embodiment of the present invention. The circuit diagram of FIG. 3B shows one or more characteristics of the circuit of FIG. 3A during load failure in at least one embodiment of the present invention. The circuit diagram of FIG. 4A shows at least one circuit element for maintaining the operability of the electrical fault indicator during load fault in at least one embodiment of the present invention; and The circuit diagram of FIG. 4B shows one or more characteristics of the circuit of FIG. 4A during load failure in at least one embodiment of the present invention.

10a: fuse

100A: Circuit

12: Electrical fault indicator

15, 20, 22: conduction path

I1, I2: current

L1: load

N1, N2, N3: Node

P1, P2: point

R1, R2: resistor

V1: Voltage source

Claims (20)

A circuit including: Connected to a fuse between two circuit points, the two circuit points are located between a voltage source and a load; Share one or more conduction paths of at least one common node with the fuse; Share a first circuit element of the at least one common node with the fuse; and An electrical fault indicator that i) shares the at least one common node with the fuse and the first circuit element, or ii) shares another common node with the first circuit element, wherein the other common node is different from the The at least one common node between the fuse and the first circuit element, When the fuse is open in response to an electrical fault, a sufficient amount of current flows through the electrical fault indicator to inform an observer that the electrical fault has occurred, and the connection of the common node to the first circuit element is The current creates a single discharge circuit, which is connected differently from any path ending in the load. The circuit of claim 1, wherein the electrical fault indicator shares the at least one common node with the fuse and the first circuit element, wherein the first circuit element is a first resistor, and the one or more The conductive path is composed of a single conductive path, which includes the electrical fault indicator connected in series with a second resistor, and wherein the single conductive path is connected in parallel with the fuse. The circuit of claim 2, wherein when i) the load is disconnected from the circuit due to a load fault condition, and when ii) the fuse is open due to an electrical fault, the first resistor and the first resistor Two resistors are connected in series with the electrical fault indicator. The circuit according to claim 3, wherein the electrical fault indicator is a light emitting diode, and wherein the electrical fault and the load fault are different from each other. The circuit of claim 1, wherein the electrical fault indicator and the first circuit element share the other common node, wherein the first circuit element is a first diode, and wherein the one or more conductive paths One of them includes a second diode in series with a gate in a transistor, and the circuit further includes: one in series with the electrical fault indicator and a drain or a source of the transistor Resistor. The circuit of claim 5, wherein the electrical fault indicator is a light emitting diode and wherein the transistor is a field effect transistor. The circuit of claim 1, wherein the electrical fault indicator and the first circuit element share the other common node, wherein the first circuit element is a first resistor, and wherein the one or more conductive paths are One of them includes a second resistor in series with a gate in a transistor, and the circuit further includes: a third resistor in series with the electrical fault indicator and a drain or a source of the transistor Resistor. The circuit of claim 7, wherein the electrical fault indicator is a light emitting diode and wherein the transistor is a field effect transistor. The circuit of claim 1, wherein the electrical fault indicator and the first circuit element share the other common node, wherein the first circuit element is a first resistor, and wherein the one or more conductive paths include i) only includes a first conductive path of a second resistor; and ii) includes only a second conductive path of a transistor device, wherein the second resistor is connected in parallel with the fuse, and wherein the second resistor The device shares a common node with a gate of the transistor, and shares a common node with a source or a drain of the transistor, and the circuit further includes: a connection with the electrical fault indicator and the transistor The drain or the source is connected in series with a third resistor. The circuit of claim 9, wherein the electrical fault indicator is a light emitting diode and wherein the transistor is a field effect transistor. The circuit of claim 1, wherein the electrical fault indicator and the first circuit element share the other common node, wherein the first circuit element is a first resistor, and wherein the one or more conductive paths include i) a first conductive path including a second resistor, ii) a second conductive path including a diode, and iii) a third conductive path including a transistor, wherein the second resistor, The fuse and the diode are connected in parallel, and the circuit further includes: a third resistor in series with the electrical fault indicator and a drain or a source of the transistor. The circuit according to claim 11, wherein the common node is a connection point of the diode, the fuse and the second resistor, and the other common node includes the fuse and the second resistor , The diode and the transistor are connected to a source or a drain and another contact. The circuit according to claim 12, wherein the diode is a Zener diode, and wherein the transistor is a field effect transistor. One method includes: Providing a fuse connected between two points between a voltage source and a load of a circuit; and Connect a fuse, a first circuit element, an electrical fault indicator and one or more conduction paths of the circuit to a common node, so that when the fuse is open in response to an electrical fault, there can be a sufficient amount of one The current passes through the electrical fault indicator to inform a user that the electrical fault has occurred, and the connection of the common node to the first circuit element creates a separate discharge loop for the current, which is different from any termination at The path of the load is connected. The method according to claim 14, wherein the first circuit element is a first resistor. The method according to claim 15, wherein the one or more conductive paths are constituted by a single conductive path, which includes the electrical fault indicator connected in series with a second resistor. The method of claim 16, wherein the single conduction path is connected in parallel with the fuse. The method according to claim 17, wherein when i) the load is disconnected from the circuit due to a load fault condition, and when ii) the fuse is open due to an electrical fault, the first resistor and the first resistor Two resistors are connected in series with the electrical fault indicator. The method according to claim 18, wherein the electrical fault indicator is a light emitting diode, and wherein the electrical fault and the load fault are different from each other. A circuit including: Connected to a fuse between two circuit points, the two circuit points being located between a voltage source and a load; At least one conduction path including a switch, the switch is in series with a resistor and an electrical fault indicator, wherein the switch and the fuse share a common node; and A relay device connected to the fuse via another node, When the fuse is operating under normal conditions, the relay device is energized according to a first state that makes the switch create an open circuit with respect to the at least one conduction path, causing the electrical fault indicator to enter a closed state, and When the fuse is open in response to an electrical fault, the relay device is powered off according to a second state, so that the electrical fault indicator enters an open state and creates a separate discharge circuit for a circuit current. The discharge circuit is different Connect to any path terminating in the load.

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