Circuit breaker
By introducing a temperature control detection circuit and a multi-level temperature alarm tripping mechanism into the circuit breaker, the safety hazards caused by the temperature rise of the wiring terminals are solved, and real-time monitoring and automatic protection of the wiring terminals are realized.
Patent Information
- Application Number
- CN202423135828.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-18
- Publication Date
- 2025-11-14
- Estimated Expiration
- 2034-12-18
AI Technical Summary
Existing circuit breakers have limitations in temperature rise protection and cannot effectively prevent temperature rises at the terminals due to loose wiring or insufficient conductor cross-sectional area, which may lead to fires or other malfunctions.
Design a circuit breaker that includes a temperature control detection circuit and a power supply circuit. The circuit breaker senses the temperature of the terminal block through a temperature control switch and issues an alarm signal or automatically cuts off power when the temperature is abnormal. It includes a multi-level temperature alarm and tripping mechanism to ensure that appropriate measures are taken under different temperature thresholds.
It enables real-time monitoring and abnormal response of terminal temperature, preventing accidents such as fires and improving the safety and stability of the circuit.
Smart Images
Figure CN223552479U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of circuit protection technology, and in particular to a circuit breaker. Background Technology
[0002] In modern power systems, circuit breakers are key devices for circuit protection, bearing the heavy responsibility of promptly cutting off power in case of overload, short circuit, or other abnormal situations, thus protecting the safety of circuits and equipment.
[0003] During the installation and use of circuit breakers, on the one hand, if the wire connections at the terminals are not tight, it will lead to increased contact resistance. As current flows, the contact resistance will generate a large amount of heat, causing the terminal temperature to rise. Prolonged exposure to high temperatures will not only accelerate the aging of the wires and terminals but also reduce their conductivity, potentially leading to serious accidents such as short circuits or fires. On the other hand, if the selected wire cross-sectional area is too small, it will be unable to withstand the current load in the circuit, causing the wires to overheat significantly. This will also raise the terminal temperature, posing a risk of fire and other malfunctions, affecting the safe and stable operation of the circuit.
[0004] However, most existing circuit breakers have overload protection functions, but they have limitations in temperature rise protection. Therefore, it is necessary to develop a circuit breaker that can monitor the temperature of the terminals and respond to abnormal temperatures. Utility Model Content
[0005] This application provides a circuit breaker that can monitor the temperature of the terminals and respond to abnormal temperatures.
[0006] The circuit breaker provided in this application includes terminal blocks, a temperature control detection circuit, and a power supply circuit. The temperature control detection circuit includes a temperature control switch and a first alarm element connected in series, both electrically connected to the power supply circuit. The power supply circuit provides power voltage to the temperature control detection circuit. The temperature control switch senses the temperature at the terminal blocks and closes when the sensed temperature exceeds a set value, thereby connecting the first alarm element to the power supply circuit. The first alarm element emits an alarm signal when connected to the power supply circuit.
[0007] Through the above scheme, the temperature control switch can sense the temperature on the terminal block and close when the sensed temperature exceeds the set value. Since the temperature control switch and the first alarm element in the temperature control detection circuit are connected in series and both are electrically connected to the power supply circuit, when the temperature control switch senses that the temperature exceeds the set value and closes, it can activate the first alarm element and connect it to the power supply circuit. At this time, the first alarm element can work normally and issue an alarm signal, so that the operator or user can know that the temperature of the current terminal block has exceeded the set value based on the alarm signal, and then take appropriate action as needed.
[0008] Therefore, the circuit breaker provided in this application can monitor the temperature of the terminals and respond when the temperature is abnormal. The response may include issuing an alarm signal as mentioned above.
[0009] In one possible design, the temperature control switch includes a first switch and a second switch, and the first alarm element includes a first device and a second device. The first switch is connected in series with the first device, the second switch is connected in series with the second device, and the first switch and the second switch are connected in parallel, with the temperature sensitivity coefficient of the first switch being smaller than that of the second switch. The setpoints include a first temperature threshold and a second temperature threshold of different magnitudes, and the alarm signals include a first alarm signal and a second alarm signal.
[0010] When the temperature at the terminal block exceeds the first temperature threshold but is less than or equal to the second temperature threshold, the first switch closes, the second switch opens, and the first device issues a first alarm signal. When the temperature at the terminal block exceeds the second temperature threshold, the first switch opens, the second switch closes, and the second device issues a second alarm signal.
[0011] Through the above scheme, the first alarm signal, the first temperature threshold, and the first switch are correlated; similarly, the second alarm signal, the second temperature threshold, and the second switch are correlated. When the first device issues the first alarm signal, the operator or user can know from this signal that the temperature of the current terminal exceeds the lower first temperature threshold. When the second device issues the second alarm signal, the operator or user can know from this signal that the temperature of the current terminal exceeds the higher second temperature threshold. This facilitates the operator or user in judging the degree of temperature abnormality based on the alarm signals and taking appropriate action.
[0012] In one possible design, the circuit breaker also includes an actuation circuit and a tripping circuit. The actuation circuit includes a relay, which includes a relay coil connected in series with a second switch and in parallel with a second device. The tripping circuit includes a trip unit, which includes a trip coil. A first terminal of the trip coil is electrically connected to the power supply circuit, and a second terminal of the trip coil is electrically connected to the normally open contact of the relay. When the second switch is closed, energizing the relay coil, the normally open contact closes, the trip coil is energized, and the trip unit trips.
[0013] With the above scheme, when the temperature at the terminal exceeds a large second temperature threshold, or exceeds a dangerous temperature value, and the second switch is closed, in addition to issuing a second alarm signal through the second device to remind the operator or user, the circuit breaker can also be automatically tripped and disconnected through the cooperation of the relay and the trip unit, thus playing an effective circuit protection role and avoiding accidents such as fires.
[0014] In one possible design, the relay also includes a normally closed contact electrically connected to a second alarm element. When the second switch is open, the normally closed contact closes, and the second alarm element is in the first state. When the second switch is closed, energizing the relay coil, the normally closed contact opens, and the second alarm element switches from the first state to the second state.
[0015] By setting a second alarm element electrically connected to a normally closed contact, when the second switch is open, the second alarm element is in the first state; when the second switch is closed, the second alarm element switches from the first state to the second state. This allows the operator or user to be alerted to abnormal temperatures at the terminal blocks by the state switching of the second alarm element, enriching the circuit breaker's response methods to abnormal temperatures at the terminal blocks.
[0016] In one possible design, the execution circuit also includes a first freewheeling diode connected in parallel with the relay.
[0017] With the above scheme, when the relay coil is de-energized, the generated reverse electromotive force can form a circuit through the first freewheeling diode and be consumed in the form of current, thereby protecting other components in the circuit.
[0018] In one possible design, the trip circuit also includes a second freewheeling diode connected in parallel with the trip unit.
[0019] Through the above scheme, the second freewheeling diode can dissipate the reverse electromotive force generated when the trip coil is de-energized, thereby protecting other components in the circuit.
[0020] In one possible design, the temperature control detection circuit also includes a first current-limiting resistor and a second current-limiting resistor. The first current-limiting resistor is connected in series with the first switch, and the second current-limiting resistor is connected in series with the second switch.
[0021] Through the above scheme, the first current-limiting resistor can limit the current flow in the circuit where the first device is located, preventing the first device and other devices from being damaged due to overheating. The second current-limiting resistor can limit the current flow in the circuit where the second device is located, preventing the second device and other devices from being damaged due to overheating.
[0022] In one possible design, the first alarm element is a buzzer or a light-emitting diode.
[0023] In one possible design, the circuit breaker also includes a leakage current detection circuit and a tripping circuit. The leakage current detection circuit includes a leakage current detection chip, and the tripping circuit includes a trip unit and a silicon controlled rectifier (SCR), with the trip unit including a trip coil.
[0024] The detection terminal of the leakage current detection circuit is electrically connected to the current transformer of the circuit breaker. The detection terminal of the leakage current detection circuit is also electrically connected to the leakage current detection chip. The output terminal of the leakage current detection circuit is electrically connected to the control electrode of the thyristor. The anode of the thyristor is electrically connected to the second terminal of the trip coil. The first terminal of the trip coil is electrically connected to the power supply circuit. The cathode of the thyristor is grounded.
[0025] The detection terminal of the leakage current detection circuit receives leakage current signals from the current transformer and transmits these signals to the leakage current detection chip. The leakage current detection chip processes the leakage current signals and outputs control signals to the thyristor. The thyristor is then activated based on the control signal, energizing the trip coil and causing the trip unit to trip.
[0026] Through the above scheme, the leakage current detection circuit can receive leakage current signals from the current transformer, process the leakage current signals to generate control signals, and transmit the control signals to the thyristor in the trip circuit, causing the thyristor to conduct based on the control signals, thereby causing the trip unit to trip. Therefore, the circuit breaker provided in this application can not only alarm and trip when the temperature at the terminals is abnormal, but also trip when leakage current occurs, improving the performance of the circuit breaker.
[0027] In one possible design, the leakage current detection circuit also includes a third current-limiting resistor, one end of which is electrically connected to the leakage current detection chip, and the other end of which is electrically connected to the trip coil.
[0028] Through the above scheme, the third current-limiting resistor can limit the current in the circuit where the leakage detection chip and the trip coil are located, preventing the leakage detection chip and other devices from being damaged due to overheating. Attached Figure Description
[0029] Figure 1 This is a schematic diagram of the circuit structure of a circuit breaker provided in an embodiment of this application.
[0030] Explanation of reference numerals in the attached figures:
[0031] 100. Temperature control detection circuit; 110. Temperature control switch; RT, first switch; RT1, second switch; 120. First alarm element; R2, first current limiting resistor; R3, second current limiting resistor;
[0032] 200. Power supply circuit; RV1. Varistor; R1. Step-down resistor; C1. Step-down capacitor; DB1. Rectifier bridge; Z1. Zener diode; C3. First filter capacitor; C4. Second filter capacitor; Z2. Zener transistor; C5. Third filter capacitor; C6. Fourth filter capacitor;
[0033] 300, Execution circuit; K1, Relay coil; Relay-DPST, Contact switch; D6, First freewheeling diode;
[0034] 400, Tripping circuit; TQQ, Tripping coil; D5, Second freewheeling diode; D1, First rectifier diode; D2, Second rectifier diode; D3, Third rectifier diode; D4, Fourth rectifier diode; Q1, SCR; C2, Anti-interference capacitor; RV2, Varistor;
[0035] 500, Leakage detection circuit; U1, Leakage detection chip; R6, Third current limiting resistor. Detailed Implementation
[0036] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims and drawings of this application are intended to cover non-exclusive inclusion.
[0038] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of the phrase "embodiment" in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0039] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists, A and B exist simultaneously, or B exists. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.
[0040] The directional terms appearing in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. For example, in the description of this application, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0041] Furthermore, the terms "first," "second," etc., in the specification and claims of this application or in the aforementioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.
[0042] In the description of this application, unless otherwise stated, "multiple" means two or more (including two), and similarly, "multiple groups" means two or more (including two groups).
[0043] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, "connection" or "linkage" in circuit structures can refer not only to physical connection but also to electrical or signal connection. This could be a direct connection (physical connection) or an indirect connection via at least one intermediate component, as long as the circuit is connected. It could also refer to the internal connection between two components. Similarly, a signal connection can refer to a connection via a circuit or a media, such as radio waves. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.
[0044] Circuit breakers are important switching devices in power systems, capable of closing, carrying, and interrupting current in circuits. When overloads, short circuits, or other faults occur in the system, circuit breakers can disconnect the circuit by opening the circuit to prevent the fault from escalating.
[0045] Due to various reasons, such as loose wiring or improper selection of conductor cross-sectional area, the terminals of circuit breakers often experience temperature rise, which can lead to fires and other malfunctions, affecting the stable operation of the power system.
[0046] However, existing circuit breakers with overload protection cannot protect against faults caused by loose wiring or small conductor cross-sectional area leading to increased terminal temperature.
[0047] In view of this, this application provides a circuit breaker that can monitor the temperature of the terminals and respond to abnormal temperatures.
[0048] The circuit breaker may be a circuit breaker with leakage protection function or a circuit breaker with overload protection function, etc., and this application does not limit it.
[0049] The circuit breaker includes terminals, which can be any one of power input terminals, power output terminals, load input terminals, and load output terminals; this application does not limit this. Therefore, the circuit breaker provided by this application can monitor the temperature of any terminal in the circuit breaker and respond when the temperature is abnormal.
[0050] The circuit breaker provided in this application will be described in detail below with reference to the accompanying drawings.
[0051] Figure 1 This is a schematic diagram of the circuit structure of a circuit breaker provided in an embodiment of this application, such as... Figure 1 As shown, the circuit breaker includes a temperature control detection circuit 100 and a power supply circuit 200. The temperature control detection circuit 100 includes a temperature control switch 110 and a first alarm element 120 connected in series. Both the temperature control switch 110 and the first alarm element 120 are electrically connected to the power supply circuit 200.
[0052] The power supply circuit 200 provides power voltage to the temperature control detection circuit 100. The temperature control switch 110 senses the temperature at the terminal block and closes when the sensed temperature exceeds a set value, thereby connecting the first alarm element 120 to the power supply circuit 200. The first alarm element 120 issues an alarm signal when connected to the power supply circuit 200.
[0053] The power supply in power supply circuit 200 can be a single-phase power supply. For example, such as... Figure 1 As shown, the power supply circuit 200 may include an A-phase line and an N-phase line. The A-phase line is equivalent to the live wire, and the N-phase line is equivalent to the neutral wire or zero wire. In this case, the power supply circuit 200 can provide a 220V power supply voltage to the temperature control detection circuit 100.
[0054] The power source in the power supply circuit 200 can also be two phase lines from a three-phase power system. For example, the power supply circuit 200 may include phase A and phase C. In this case, the power supply circuit 200 can provide a 380V power supply voltage to the temperature control detection circuit 100.
[0055] like Figure 1As shown, in some examples, the power supply circuit 200 may include a varistor RV1, one end of which is electrically connected to phase A and the other end of which is electrically connected to phase N. The varistor RV1 in the power supply circuit 200 serves to protect against overvoltage and suppress surge current, thereby improving the reliability of the circuit in the circuit breaker.
[0056] In some examples, the power supply circuit 200 may also include a step-down resistor R1 and / or a step-down capacitor C1. Although the step-down resistor R1 and the step-down capacitor C1 operate on different principles, both are connected in series in the power supply circuit 200 and can reduce the voltage.
[0057] In some examples, the power supply circuit 200 may also include a rectifier bridge DB1. For example... Figure 1 As shown, one AC interface of rectifier bridge DB1 is electrically connected to phase A, and the other AC interface of rectifier bridge DB1 is electrically connected to phase N. The positive interface V+ of rectifier bridge DB1 is electrically connected to the input terminal of temperature control detection circuit 100, and the negative interface V- of rectifier bridge DB1 is electrically connected to the output terminal of temperature control detection circuit 100. Rectifier bridge DB1 is used to convert AC power to DC power and provide DC voltage to temperature control detection circuit 100.
[0058] In some examples, the power supply circuit 200 may also include a Zener diode Z1, and / or a first filter capacitor C3, and / or a second filter capacitor C4. The Zener diode Z1, the first filter capacitor C3, and the second filter capacitor C4 are connected in parallel, and all three are connected in parallel between the positive interface V+ and the negative interface V- of the rectifier bridge DB1.
[0059] Among them, the Zener diode Z1 can stabilize the voltage and protect the circuit.
[0060] The first filter capacitor C3 and the second filter capacitor C4 can filter out noise and stabilize voltage.
[0061] In some examples, the power supply circuit 200 may also include a voltage regulating transistor Z2, and / or a third filter capacitor C5, and / or a fourth filter capacitor C6.
[0062] In this circuit, the base Vin of the voltage-regulating transistor Z2 is electrically connected to the positive terminal of the second filter capacitor C4, the collector Vout of the voltage-regulating transistor Z2 is electrically connected to the input terminal of the temperature control detection circuit 100, and the emitter of the voltage-regulating transistor Z2 is grounded or electrically connected to the negative terminal of the second filter capacitor C4. The voltage-regulating transistor Z2 is connected between the input terminal of the temperature control detection circuit 100 and the power supply, and can regulate the input voltage of the temperature control detection circuit 100.
[0063] Similar to the first filter capacitor C3 and the second filter capacitor C4, the third filter capacitor C5 and the fourth filter capacitor C6 can also filter out noise and stabilize voltage.
[0064] Based on the power supply circuit 200 described in the above example, the temperature control switch 110 and the first alarm element 120 can be electrically connected to the power supply circuit 200 in the following ways: one end of the temperature control switch 110 is electrically connected to one end of the first alarm element 120, the other end of the temperature control switch 110 is connected to the positive terminal of the power supply, and the other end of the first alarm element 120 is electrically connected to the negative terminal of the power supply. This implementation is not the only one and does not constitute a limitation on the technical solution of this application. For example, if the positions of the series-connected temperature control switch 110 and the first alarm element 120 are interchanged, the electrical connection relationship in the above implementation will be adjusted accordingly.
[0065] The connection to the positive terminal of the power supply can be achieved by connecting it to the positive interface V+ of the rectifier bridge DB1, or by connecting it to the positive terminal of the third filter capacitor C5. Similarly, the connection to the negative terminal of the power supply can be achieved by connecting it to the negative interface V- of the rectifier bridge DB1, or by connecting it to the negative terminal of the third filter capacitor C5.
[0066] The temperature control switch 110 is also called a temperature protector, temperature controller, or thermostat. The temperature control switch 110 can be resistive or thermocouple type, and this application does not limit it in this regard.
[0067] In this application, the temperature control switch 110 can be attached to the terminal block corresponding to the power supply or load's input or output terminals to sense the temperature on the terminals. Furthermore, the temperature control switch 110 can sense the temperature on the terminals in real time.
[0068] When the temperature sensed by the temperature control switch 110 does not exceed the set value, the resistance of the temperature control switch 110 is infinite, and the temperature control switch 110 remains in the open state and does not conduct. Conversely, when the temperature sensed by the temperature control switch 110 exceeds the set value, the resistance of the temperature control switch 110 is infinite, and the temperature control switch 110 is closed.
[0069] Since the temperature control switch 110 and the first alarm element 120 are connected in series, and both the temperature control switch 110 and the first alarm element 120 are electrically connected to the power supply circuit 200, when the temperature control switch 110 is in the open state, the first alarm element 120 is not connected to the power supply circuit 200, and therefore will not emit an alarm signal. When the temperature control switch 110 is in the closed state, the first alarm element 120 is connected to the power supply circuit 200, and therefore will emit an alarm signal.
[0070] The set value can be set according to actual needs, specifically according to national standards or customer requirements. For example, the set value can be 20℃, 60℃, 70℃, 120℃, etc., and this application does not limit it.
[0071] When the first alarm element 120 is connected to the power supply circuit 200, it can emit an alarm signal. The alarm signal can be a flashing light of a specific color, a continuously lit light of a specific color, a continuous piercing sound, or intermittent short sounds, etc., and this application does not limit it. Among them, the specific color can be red.
[0072] The first alarm unit 120 issues an alarm signal, which can quickly attract the attention of operators or users. Based on this alarm signal, operators or users can know that the temperature of the current wiring terminal has exceeded the set value and can take appropriate action as needed.
[0073] The circuit breaker provided in this application includes a temperature control detection circuit 100, which includes a temperature control switch 110. The temperature control switch 110 can sense the temperature on the terminal block and closes when the sensed temperature exceeds a set value. Since the temperature control switch 110 and the first alarm element 120 in the temperature control detection circuit 100 are connected in series and both are electrically connected to the power supply circuit 200, when the temperature control switch 110 senses that the temperature exceeds the set value and closes, it can turn on the first alarm element 120 and the power supply circuit 200. At this time, the first alarm element 120 can work normally and issue an alarm signal so that the operator or user knows that the temperature of the current terminal block exceeds the set value based on the alarm signal, and then takes appropriate action as needed.
[0074] Therefore, the circuit breaker provided in this application can monitor the temperature of the terminals and respond when the temperature is abnormal. The response may include issuing an alarm signal as mentioned above.
[0075] In some embodiments, the first alarm element 120 may be a buzzer or a light-emitting diode to alert to abnormal temperature phenomena through sound or color. Of course, the first alarm element 120 may also be other devices capable of emitting alarm signals, and this application does not limit this to any particular type.
[0076] According to some embodiments of this application, such as Figure 1 As shown, the temperature control switch 110 may include a first switch RT and a second switch RT1, and the first alarm element 120 may include a first device and a second device. The first switch RT is connected in series with the first device, the second switch RT1 is connected in series with the second device, and the first switch RT and the second switch RT1 are connected in parallel. The temperature sensitivity coefficient of the first switch RT is smaller than that of the second switch RT1. The set values include a first temperature threshold and a second temperature threshold of different magnitudes, and the alarm signals include a first alarm signal and a second alarm signal.
[0077] When the temperature at the terminal block exceeds the first temperature threshold but is less than or equal to the second temperature threshold, the first switch RT closes, the second switch RT1 opens, and the first device issues a first alarm signal. When the temperature at the terminal block exceeds the second temperature threshold, the first switch RT opens, the second switch RT1 closes, and the second device issues a second alarm signal.
[0078] The first switch RT and the first device are connected in series and are both electrically connected to the power supply circuit 200. The second switch RT1 and the second device are connected in series and are both electrically connected to the power supply circuit 200. The circuit containing the first switch RT and the first device is connected in parallel to the circuit containing the second switch RT1 and the second device. Thus, the first switch RT and the first device are connected in series and in parallel to the second switch RT1 and the second device, which are connected in series.
[0079] The temperature sensitivity coefficients of the first switch RT and the second switch RT1 are different. Specifically, the temperature sensitivity coefficient of the first switch RT can be set to be smaller than that of the second switch RT1. In this way, under the same temperature change, the first switch RT, with its smaller temperature sensitivity coefficient, will reach its operating temperature more quickly, thus making it easier to close and conduct.
[0080] To this end, a first temperature threshold and a second temperature threshold of different values are set to provide different conduction conditions for the first switch RT and the second switch RT1. Specifically, the first temperature threshold can be set smaller than the second temperature threshold.
[0081] For example, the first temperature threshold could be 70°C, and the second temperature threshold could be 100°C. In this case, when the temperature at the terminal is greater than or equal to 70°C and less than or equal to 100°C, the first switch RT closes, and the first device issues a first alarm signal. At this time, the second switch RT1 remains open. When the temperature at the terminal rises to greater than 100°C, the first switch RT opens, the second switch RT1 closes, and the second device issues a second alarm signal.
[0082] It is evident that the first switch RT and the second switch RT1 can conduct under different temperature conditions. Because the conduction conditions of the first switch RT and the second switch RT1 are different, the first alarm signal emitted by the first device when the first switch RT is closed and the second alarm signal emitted by the second device when the second switch RT1 is closed can be distinguished. This allows operators or users to know the current temperature level of the terminal block based on the different first and second alarm signals.
[0083] For example, the first alarm signal could be a flashing green light, and the second alarm signal could be a flashing red light. Alternatively, the first alarm signal could be an intermittent, short audible sound, and the second alarm signal could be a continuous, piercing sound.
[0084] The first switch RT and the first device are connected in series and in parallel to the second switch RT1 and the second device, which are also connected in series. The temperature sensitivity coefficient of the first switch RT is less than that of the second switch RT1. Therefore, when the temperature at the terminal is greater than the smaller first temperature threshold and less than or equal to the larger second temperature threshold, only the first switch RT closes, while the second switch RT1 remains open. In this case, only the first device issues a first alarm signal. When the temperature at the terminal is greater than the larger second temperature threshold, only the second switch RT1 closes, while the first switch RT remains open. In this case, only the second device issues a second alarm signal.
[0085] As can be seen, the first alarm signal, the first temperature threshold, and the first switch RT are related, and the second alarm signal, the second temperature threshold, and the second switch RT1 are related. Therefore, when the first device issues the first alarm signal, the operator or user can know that the temperature of the current terminal exceeds the lower first temperature threshold based on the first alarm signal. When the second device issues the second alarm signal, the operator or user can know that the temperature of the current terminal exceeds the higher second temperature threshold based on the second alarm signal. This allows the operator or user to judge the degree of temperature abnormality based on the alarm signals and take appropriate action as needed.
[0086] Based on the above, in some embodiments, such as Figure 1 As shown, the temperature control detection circuit 100 may further include a first current-limiting resistor R2 and a second current-limiting resistor R3. The first current-limiting resistor R2 is connected in series with the first switch RT, and the second current-limiting resistor R3 is connected in series with the second switch RT1.
[0087] The first current-limiting resistor R2 is connected in series with the first switch RT and the first device. When the first switch RT is closed, current will flow through the circuit containing the first device. The first current-limiting resistor R2 limits the current flow in the circuit containing the first device, preventing the first device and other devices from being damaged due to overheating.
[0088] Similarly, the second current-limiting resistor R3 is connected in series with the second switch RT1 and the second device. When the second switch RT1 is closed, current will flow through the circuit containing the second device. The second current-limiting resistor R3 limits the current flow in the circuit containing the second device, preventing the second device and other devices from being damaged due to overheating.
[0089] Please continue to refer to Figure 1 The circuit breaker may also include an execution circuit 300 and a tripping circuit 400.
[0090] The execution circuit 300 includes a relay, which includes a relay coil K1. The relay coil K1 is connected in series with the second switch RT1, and the relay coil K1 is connected in parallel with the second device. The trip circuit 400 includes a trip unit, which includes a trip coil TQQ. The first end of the trip coil TQQ is electrically connected to the power supply circuit 200, and the second end of the trip coil TQQ is electrically connected to the normally open contact of the relay.
[0091] The relay includes a relay coil K1 and a contact switch Relay-DPST. The contact switch Relay-DPST may include normally open contacts and / or normally closed contacts. When the contact switch Relay-DPST is normally open, it closes when the relay coil K1 is energized. Conversely, it opens when the relay coil K1 is de-energized. Similarly, when the contact switch Relay-DPST is normally closed, it opens when the relay coil K1 is energized. Conversely, it closes when the relay coil K1 is de-energized.
[0092] One end of the relay coil K1 is electrically connected between the second device and the second switch RT1, and the other end of the relay coil K1 is electrically connected between the second device and the power supply circuit 200, so that the relay coil K1 and the second switch RT1 are connected in series and in parallel with the second device. Thus, when the second switch RT1 is closed, the second device sends a second alarm signal, and simultaneously, the relay coil K1 is energized, causing its normally open contact to close and its normally closed contact to open. The actions of the second device and the relay coil K1 are independent of each other and do not affect each other.
[0093] A trip unit includes a trip coil (TQQ) and a moving iron core, etc. For example... Figure 1 As shown, the first end of the trip coil TQQ is electrically connected to the N-phase line, and the second end of the trip coil TQQ is electrically connected to the normally open contact of the relay. Thus, once the relay coil K1 is energized and the normally open contact closes, the trip coil TQQ is energized. When the trip coil TQQ is energized, it generates a magnetic field. Under the influence of this magnetic field, the moving iron core moves, causing the trip unit to trip. After the trip unit trips, the circuit breaker containing the trip unit will trip and disconnect the power. This prevents accidents such as fires from occurring if the circuit breaker fails to disconnect the power in time when the temperature at the terminals exceeds the higher second alarm signal.
[0094] In summary, the circuit breaker includes an execution circuit 300 and a tripping circuit 400. In the execution circuit 300, the relay coil K1 is connected in series with the second switch RT1. In the tripping circuit 400, the tripping coil TQQ of the trip unit is electrically connected to the normally open contact of the relay. Thus, when the second switch RT1 is closed, the relay coil K1 is energized, causing the normally open contact to close. Subsequently, the tripping coil TQQ is energized, causing the trip unit to trip, thereby tripping the circuit breaker and disconnecting the power.
[0095] As can be seen, when the temperature at the terminal exceeds a large second temperature threshold, or exceeds a dangerous temperature value, and the second switch RT1 is closed, in addition to issuing a second alarm signal through the second device to remind the operator or user, the circuit breaker can also be automatically tripped and disconnected through the cooperation of the relay and the trip unit, thus playing an effective circuit protection role and preventing accidents such as fires.
[0096] It is worth noting that this application connects the relay coil K1 in series only with the second switch RT1, and not with the first switch RT. This ensures that when the temperature at the terminal exceeds the first temperature threshold but not the second temperature threshold, it only alarms but does not trip. Conversely, when the temperature at the terminal exceeds the second temperature threshold, it both alarms and trips. This design is necessary because in certain special situations, the circuit breaker is not allowed to trip, but only to alarm to indicate an abnormal temperature. In such special situations, users can manually disconnect the power for troubleshooting and maintenance at a convenient time based on the alarm prompt, thus improving the applicability of the circuit breaker.
[0097] The application of normally open contacts in the Relay-DPST contact switch has been introduced above. The application of normally closed contacts in the Relay-DPST contact switch will be introduced below.
[0098] In some embodiments, the normally closed contact can be electrically connected to the second alarm element. When the second switch RT1 is open, the normally closed contact is closed, and the second alarm element is in the first state. When the second switch RT1 is closed, energizing the relay coil K1, the normally closed contact is open, and the second alarm element switches from the first state to the second state.
[0099] Similar to the first alarm element 120, the second alarm element can also be a buzzer or an LED capable of emitting an alarm signal. In this application, where both the first alarm element 120 and the second alarm element are provided, the first alarm element 120 can be installed at the site of use, while the second alarm element can be installed in the control center or other locations far from the site where personnel are on duty. Thus, when the operator or user is not on-site and cannot be notified of an abnormal temperature at the terminal block through the first alarm element 120, the second alarm element can be used to understand the situation.
[0100] When the temperature at the terminal block does not exceed the second temperature threshold, the second switch RT1 remains open, the relay coil K1 is not energized, the normally closed contact remains closed, and the second alarm element remains in the first state. This first state is the normal state. When the temperature at the terminal block exceeds the second temperature threshold, the second switch RT1 switches from the open state to the closed state, the relay coil K1 is energized, the normally closed contact switches from the closed state to the open state, and the second alarm element switches from the first state to the second state.
[0101] For example, assuming the second alarm element is a light-emitting diode, the first state can be that the green light is constantly on, and the second state can be that the green light is off.
[0102] In this embodiment, a second alarm element is electrically connected to a normally closed contact. When the second switch RT1 is open, the second alarm element is in the first state; when the second switch RT1 is closed, the second alarm element switches from the first state to the second state. This allows the operator or user to be alerted to abnormal temperatures at the terminal blocks by the state switching of the second alarm element, enriching the circuit breaker's response methods to abnormal temperatures at the terminal blocks.
[0103] Please continue to refer to Figure 1 The execution circuit 300 may also include a first freewheeling diode D6, which is connected in parallel with the relay.
[0104] like Figure 1 As shown, the first freewheeling diode D6 is connected in reverse parallel across the relay coil K1. Specifically, the positive terminal of the first freewheeling diode D6 is electrically connected to the end of the relay coil K1 that is connected to the negative terminal of the power supply, and the negative terminal of the first freewheeling diode D6 is electrically connected to the end of the relay coil K1 that is connected to the positive terminal of the power supply. In this way, when the relay coil K1 is de-energized, the generated reverse electromotive force can form a circuit through the first freewheeling diode D6 and be dissipated in the form of current, thereby protecting other components in the circuit.
[0105] Please continue to refer to Figure 1 The trip circuit 400 also includes a second freewheeling diode D5, which is connected in parallel with the trip unit.
[0106] The second freewheeling diode D5 is connected in parallel across the trip coil TQQ. Similar to the first freewheeling diode D6, the second freewheeling diode D5 can dissipate the reverse electromotive force generated when the trip coil TQQ is de-energized, thereby protecting other components in the circuit.
[0107] In some embodiments, such as Figure 1 As shown, the trip circuit 400 may further include a first rectifier diode D1, a second rectifier diode D2, a third rectifier diode D3, and a fourth rectifier diode D4. These four rectifier diodes can form a rectifier bridge DB1 to convert alternating current into direct current.
[0108] Please continue to refer to Figure 1 In some embodiments, such as Figure 1 As shown, the circuit breaker may also include a leakage current detection circuit 500. The leakage current detection circuit 500 includes a leakage current detection chip U1, and the tripping circuit 400 also includes a thyristor Q1.
[0109] The detection terminal of the leakage current detection circuit 500 is electrically connected to the current transformer of the circuit breaker. The detection terminal of the leakage current detection circuit 500 is also electrically connected to the leakage current detection chip U1. The output terminal of the leakage current detection circuit 500 is electrically connected to the control electrode of the thyristor Q1. The anode of the thyristor Q1 is electrically connected to the second terminal of the trip coil TQQ. The first terminal of the trip coil TQQ is electrically connected to the power supply circuit 200. The cathode of the thyristor Q1 is grounded.
[0110] The detection terminal of the leakage current detection circuit 500 is electrically connected to the current transformer of the circuit breaker to receive leakage current signals from the current transformer. The detection terminal of the leakage current detection circuit 500 is also electrically connected to the signal input pin of the leakage current detection chip U1. After receiving a leakage current signal, the detection terminal of the leakage current detection circuit 500 can transmit the leakage current signal to the leakage current detection chip U1 through the signal input pin.
[0111] For example, such as Figure 1 As shown, the leakage current detection chip U1 includes 8 pins. One detection terminal Hqq of the leakage current detection circuit 500 is electrically connected to pin 1 of the leakage current detection chip U1, and the other detection terminal Hqq1 of the leakage current detection circuit 500 is electrically connected to the signal input pin 2 of the leakage current detection chip U1, so that the detection terminals Hqq and Hqq1 transmit the leakage current signal to the leakage current detection chip U1 through pins 1 and 2.
[0112] After receiving a leakage current signal, the leakage current detection chip U1 can process the leakage current signal and generate a control signal. The processing of the leakage current signal by the leakage current detection chip U1 includes, but is not limited to, amplifying the leakage current signal and filtering out interference signals in the leakage current signal.
[0113] The output of the leakage current detection circuit 500 corresponds to the signal output pin of the leakage current detection chip U1. Since the output of the leakage current detection circuit 500 is electrically connected to the control electrode of the thyristor Q1, after the leakage current detection chip U1 generates a control signal, the control signal can be output to the control electrode of the thyristor Q1 through the signal output pin of the leakage current detection chip.
[0114] For example, such as Figure 1 As shown, pin 7 of the leakage current detection chip U1 is the output terminal of the leakage current detection circuit 500.
[0115] Subsequently, the thyristor Q1 can be turned on based on the control signal, which will energize the trip coil TQQ and cause the trip unit to trip.
[0116] This embodiment incorporates a leakage current detection circuit 500 and a tripping circuit 400 within the circuit breaker. The leakage current detection circuit 500 receives leakage current signals from the current transformer, processes these signals to generate a control signal, and transmits this control signal to the thyristor Q1 in the tripping circuit 400. This causes the thyristor Q1 to conduct based on the control signal, thereby tripping the circuit breaker. Therefore, the circuit breaker provided in this application can not only alarm and trip when there is an abnormal temperature at the terminals, but also trip when a leakage current occurs, improving the circuit breaker's performance.
[0117] like Figure 1 As shown, the trip circuit 400 may also include an anti-interference capacitor C2, one plate of which is electrically connected to the control electrode of the thyristor Q1, and the other plate of which is electrically connected to the cathode of the thyristor Q1, or the other plate of which is grounded.
[0118] As can be seen, the anti-interference capacitor C2 is connected in parallel between the control electrode and the cathode of the thyristor Q1. This creates a low-impedance path, shunting the high-frequency noise signal on the control electrode of the thyristor Q1, thereby reducing interference to the control electrode. Furthermore, the anti-interference capacitor C2 also protects the thyristor Q1 from transient voltage or current surges, thus protecting it.
[0119] In some examples, such as Figure 1 As shown, the trip circuit 400 may also include a varistor RV2. The varistor RV2 is connected in parallel between the anode and cathode of the thyristor Q1, and can provide overvoltage protection for the thyristor Q1.
[0120] All of the components in the trip circuit 400 can be integrated onto the leakage circuit board.
[0121] Please continue to refer to Figure 1 In some embodiments, such as Figure 1 As shown, the leakage current detection circuit 500 may further include a third current-limiting resistor R6. One end of the third current-limiting resistor R6 is electrically connected to the leakage current detection chip U1, and the other end of the third current-limiting resistor R6 is electrically connected to the trip coil TQQ. In other words, the third current-limiting resistor R6 is connected in series with the leakage current detection chip U1 and the trip coil TQQ.
[0122] like Figure 1 As shown, one end of the third current-limiting resistor R6 is electrically connected to pin 8 of the leakage current detection chip U1.
[0123] With this configuration, the current in the circuit containing the leakage detection chip U1 and the trip coil TQQ can be limited by the third current-limiting resistor R6, preventing the leakage detection chip U1 and other devices from being damaged due to overheating.
[0124] In some examples, an adjusting resistor R5 is connected in parallel between the detection terminals Hqq and Hqq1 of the leakage current detection circuit 500 to adjust the current flowing through the leakage current detection circuit 500, thereby protecting the leakage current detection circuit 500. A current-limiting resistor R4 is also connected between the detection terminal Hqq1 and pin 2 to limit the current.
[0125] In some examples, a limiting bidirectional diode D7 is connected in parallel between the detection terminals Hqq and Hqq1 of the leakage current detection circuit 500. The limiting bidirectional diode D7 in the leakage current detection circuit 500 has bidirectional conduction and triggering functions, and can also play a role in voltage limiting protection, interference suppression and noise suppression.
[0126] In some examples, pins 4 and 5 of the leakage current detection chip U1 are grounded through an anti-interference capacitor C8. An anti-interference capacitor C9 is connected between pins 3 and 1 of the leakage current detection chip U1. An anti-interference capacitor C10 is connected between pins 1 and 2 of the leakage current detection chip U1. Pin 2 is grounded through an anti-interference capacitor C11. An anti-interference capacitor C12 is connected between pins 6 and 7. An anti-interference capacitor C13 is also connected in parallel between the detection terminals Hqq and Hqq1 of the leakage current detection circuit 500. These anti-interference capacitors all serve to protect the circuit.
[0127] In some examples, the leakage current detection circuit 500 also includes a filter capacitor C7 and a Zener diode Z2 connected in parallel.
[0128] One end of the filter capacitor C7 and the Zener diode Z2 is electrically connected between the third current limiting resistor R6 and pin 8 of the leakage current detection chip U1, and the other end of the filter capacitor C7 and the Zener diode Z2 is grounded.
[0129] The filter capacitor C7 serves to filter out noise and stabilize the voltage. The Zener diode Z2 serves to stabilize the voltage and protect the circuit.
Claims
1. A circuit breaker, comprising terminals, characterized in that, The circuit breaker includes: a temperature control detection circuit and a power supply circuit; The temperature control detection circuit includes a temperature control switch and a first alarm element connected in series, and both the temperature control switch and the first alarm element are electrically connected to the power supply circuit. The power supply circuit is used to provide power voltage to the temperature control detection circuit; The temperature control switch is used to sense the temperature on the terminal block and closes when the sensed temperature exceeds the set value, so as to connect the first alarm element to the power circuit. The first alarm element is used to issue an alarm signal when it is connected to the power supply circuit.
2. The circuit breaker according to claim 1, characterized in that, The temperature control switch includes a first switch and a second switch, and the first alarm component includes a first device and a second device. The first switch is connected in series with the first device, the second switch is connected in series with the second device, the first switch and the second switch are connected in parallel, and the temperature sensitivity coefficient of the first switch is smaller than that of the second switch. The set values include a first temperature threshold and a second temperature threshold of different values, and the alarm signals include a first alarm signal and a second alarm signal. When the temperature at the terminal is greater than the first temperature threshold and less than or equal to the second temperature threshold, the first switch is closed, the second switch is opened, and the first device emits the first alarm signal. When the temperature at the terminal exceeds the second temperature threshold, the first switch opens, the second switch closes, and the second device issues the second alarm signal.
3. The circuit breaker according to claim 2, characterized in that, The circuit breaker also includes an execution circuit and a tripping circuit; The execution circuit includes a relay, the relay includes a relay coil, the relay coil is connected in series with the second switch, and the relay coil is connected in parallel with the second device; The tripping circuit includes a trip unit, the trip unit includes a trip coil, a first end of the trip coil is electrically connected to the power supply circuit, and a second end of the trip coil is electrically connected to the normally open contact of the relay. When the second switch is closed to energize the relay coil, the normally open contact closes, the trip coil is energized, and the trip unit trips.
4. The circuit breaker according to claim 3, characterized in that, The relay also includes a normally closed contact, which is electrically connected to a second alarm element. When the second switch is open, the normally closed contact is closed, and the second alarm element is in the first state; When the second switch is closed and the relay coil is energized, the normally closed contact opens, and the second alarm element switches from the first state to the second state.
5. The circuit breaker according to claim 3, characterized in that, The execution circuit also includes a first freewheeling diode, which is connected in parallel with the relay.
6. The circuit breaker according to claim 3, characterized in that, The tripping circuit also includes a second freewheeling diode, which is connected in parallel with the trip unit.
7. The circuit breaker according to claim 2, characterized in that, The temperature control detection circuit also includes a first current-limiting resistor and a second current-limiting resistor. The first current-limiting resistor is connected in series with the first switch, and the second current-limiting resistor is connected in series with the second switch.
8. The circuit breaker according to any one of claims 1 to 7, characterized in that, The first alarm device is a buzzer or a light-emitting diode.
9. The circuit breaker according to claim 1, characterized in that, The circuit breaker also includes a leakage current detection circuit and a tripping circuit; The leakage current detection circuit includes a leakage current detection chip, and the tripping circuit further includes a tripping device and a silicon controlled rectifier (SCR), wherein the tripping device includes a tripping coil; The detection terminal of the leakage current detection circuit is electrically connected to the current transformer of the circuit breaker. The detection terminal of the leakage current detection circuit is also electrically connected to the leakage current detection chip. The output terminal of the leakage current detection circuit is electrically connected to the control electrode of the thyristor. The anode of the thyristor is electrically connected to the second terminal of the trip coil. The first terminal of the trip coil is electrically connected to the power supply circuit. The cathode of the thyristor is grounded. The detection terminal of the leakage current detection circuit is used to receive leakage current signals from the current transformer and transmit the leakage current signals to the leakage current detection chip; The leakage current detection chip is used to process the leakage current signal and output a control signal to the thyristor; The thyristor is used to conduct based on the control signal, so that the trip coil is energized and the trip unit is tripped.
10. The circuit breaker according to claim 9, characterized in that, The leakage current detection circuit also includes a third current-limiting resistor, one end of which is electrically connected to the leakage current detection chip, and the other end of which is electrically connected to the trip coil.