Magnetic switch

Abstract

The utility model relates to the technical field of magnetic switches, in particular to a magnetic switch which comprises a magnetic induction chip and a driving chip, the magnetic induction chip sends a control signal to the driving chip based on magnetic field change, and the driving chip sends load current or load voltage to a load based on the control signal; the driving chip comprises a signal path switch and an overload and overcurrent detection circuit; the overload and overcurrent detection circuit comprises a load voltage detection circuit, a comparison circuit and a logic circuit; the load voltage detection circuit detects load voltage and sends the load voltage to the comparison circuit; the comparison circuit compares the load voltage with the reference voltage and inputs a comparison result into the logic circuit; and the logic circuit is connected with the signal path switch, and sends an open circuit signal to the signal path switch when the time when the load voltage is greater than the reference voltage exceeds the overload time. According to the magnetic switch, the magnetic induction chip and the driving chip are modularly arranged, so that patch production and detection are facilitated, and each function design of the driving chip is more flexible.

Description

Technical Field

[0001] The embodiments of this specification relate to the technical field of magnetic switches, and particularly to a magnetic switch. Background Art

[0002] A magnetic switch is a line switch device controlled by magnetic field signals, mainly composed of a magnet, an induction element, a signal processing circuit, etc. The magnet is responsible for generating a magnetic field. The induction element generates corresponding electrical signals based on the change of the magnetic field. The signal processing circuit amplifies and shapes the electrical signals and then outputs them to the load so that they can be recognized and utilized by the load. In existing magnetic switches, the induction element and the signal processing circuit are usually integrated into a single chip, which is not convenient for separately producing and testing each functional module in the induction element and the signal processing circuit, and is also not conducive to the combination and expansion of functions. Moreover, functions such as overload and overcurrent detection and over-temperature detection in existing signal processing circuits have weak tolerance for abnormal signals or abnormal environments, and are prone to frequent pauses in the normal operation of the chip due to individual abnormal situations, damaging the chip while increasing the manual maintenance cost and unable to guarantee work efficiency. Summary of the Utility Model

[0003] The embodiments of this specification provide a magnetic switch, aiming to solve one or more of the above problems and other potential problems.

[0004] To achieve the above object, the following technical solutions are provided:

[0005] This specification provides a magnetic switch, including a magnetic induction chip and a drive chip. The magnetic induction chip sends a control signal to the drive chip based on the magnetic field change after sensing the magnetic field change. The drive chip sends a load current or a load voltage to the load based on the control signal. The drive chip includes a signal path switch and an overload and overcurrent detection circuit. The signal path switch is used to send a load current or a load voltage to the load based on the control signal. The overload and overcurrent detection circuit includes a load voltage detection circuit, a comparison circuit, and a logic circuit. The load voltage detection circuit is used to detect the load voltage and send the load voltage to the comparison circuit. The comparison circuit compares the magnitudes of the load voltage and a reference voltage and inputs the comparison result into the logic circuit. The logic circuit is connected to the signal path switch, and the logic circuit is used to send an open-circuit signal to the signal path switch when the time when the load voltage is greater than the reference voltage exceeds the overload time.

[0006] In the embodiments of this specification, the magnetic induction chip and the drive chip of the magnetic switch are separately connected, enabling the separate production and testing of the magnetic induction chip and the drive chip, facilitating troubleshooting and maintenance replacement, and also being conducive to the functional expansion and combination of the drive chip, deepening the diversification degree of the magnetic switch and enhancing its adaptability. The overload and overcurrent detection circuit in the drive chip will trigger the disconnection of the signal path switch only when the overload and overcurrent situation exceeds a certain time, having a strong tolerance for individual abnormal signals. The magnetic switch is not easily affected by individual abnormal situations and frequently disconnected, reducing the manual maintenance cost.

[0007] In some embodiments, the logic circuit is further connected to an error reporting circuit, and the error reporting circuit is connected to an indicator light externally connected to the drive chip; when the logic circuit sends the disconnection signal, it also sends an error reporting signal to the error reporting circuit, and after receiving the error reporting signal, the error reporting circuit sends a flashing signal to the indicator light.

[0008] In some embodiments, the logic circuit includes a second timer, and the second timer starts timing when the error reporting signal is sent; when the logic circuit determines that the timing time exceeds the overcurrent protection time, it sends an open circuit signal to the signal path switch and sends a stop flashing signal to the indicator light through the error reporting circuit.

[0009] In some embodiments, the logic circuit further includes a counter, and the counter counts the number of times the disconnection signal is sent. When the number exceeds the number threshold, the timer is reset to zero and stops timing.

[0010] In some embodiments, the load voltage detection circuit includes a current detection resistor, and the current detection resistor is connected to the load and is used to detect the load current and convert the load current into the load voltage.

[0011] In some embodiments, the comparison circuit includes a comparator. Two input terminals of the comparator are respectively connected to the output terminal of the load voltage detection circuit and the reference voltage, and the output terminal of the comparator is connected to the input terminal of the logic circuit; the comparator sends different level signals to the logic circuit based on the comparison result of the load voltage and the reference voltage; when the first timer in the logic circuit receives the level signal corresponding to the load voltage being higher than the reference voltage, it starts timing and stops until the level signal changes. When the timing time exceeds the overload time, the logic circuit sends a disconnection signal to the signal path switch.

[0012] In some embodiments, the port of the comparator for inputting the reference voltage is externally connected to an adjustable resistor.

[0013] In some embodiments, the output terminal of the magnetic induction chip is connected to the input terminal of the drive chip, and the power supply terminal of the magnetic induction chip is connected to one of the output terminals of the drive chip.

[0014] In some embodiments, pull-down capacitors are connected to the power supply terminals of both the drive chip and the magnetic induction chip.

[0015] In some embodiments, a voltage stabilizing circuit is internally connected to the output interface of the drive chip connected to the power supply terminal of the magnetic induction chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] By referring to the accompanying drawings and reading the following detailed description, the above and other objects, features, and advantages of the embodiments of this specification will become readily understood. In the drawings, several embodiments of this specification are shown by way of example and not limitation.

[0017] Figure 1 Shows a circuit diagram of a magnetic switch according to an embodiment of this specification;

[0018] Figure 2 Shows a schematic diagram of an overload and overcurrent circuit according to an embodiment of this specification;

[0019] Figure 3 Shows a circuit diagram of an NPN three-wire magnetic switch according to an embodiment of this specification;

[0020] Figure 4 Shows a circuit diagram of a PNP three-wire magnetic switch according to an embodiment of this specification.

[0021] 1 - Magnetic induction chip, 2 - Drive chip 2, C1 - First pull-down capacitor, C2 - Second pull-down capacitor, D1 - Indicator light.

[0022] In each of the drawings, the same or corresponding reference numerals denote the same or corresponding parts. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The preferred embodiments of this specification will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of this specification are shown in the drawings, it should be understood that this specification can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that this specification will be more thorough and complete, and will fully convey the scope of this specification to those skilled in the art.

[0024] As used herein, the term "including" and its variations mean open inclusion, i.e., "including but not limited to". Unless otherwise specified, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "upper", "lower", "front", "rear", etc., which indicate the placement or positional relationship, are all based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the principles of this specification, rather than indicating or implying that the elements referred to must have a specific orientation, be constructed or operated in a specific orientation, and thus should not be construed as a limitation to this specification.

[0025] The following will describe in detail a magnetic switch according to an embodiment of this specification with reference to the drawings. Figure 1 The circuit diagram of a magnetic switch according to an embodiment of this specification is shown, specifically the circuit diagram of a two-wire magnetic switch. The magnetic switch according to an embodiment of this specification includes a magnetic induction chip 1 and a drive chip 2. After the magnetic induction chip 1 senses the magnetic field change, it sends a control signal to the drive chip 2 based on the magnetic field change. The drive chip 2 sends a load current or a load voltage to the load based on the control signal. The magnetic induction chip 1 for magnetic field induction and the drive chip 2 for function expansion are separately connected, enabling separate production and testing of the magnetic induction chip 1 and the drive chip 2, making troubleshooting more targeted. Moreover, when one of the chips fails, it can be flexibly replaced, reducing the maintenance cost. Different functions can be integrated in the drive chip 2, and the drive chip 2 with different functions can be used according to different requirements, making the combination and expansion of functions more flexible and convenient.

[0026] Figure 3 and Figure 4 The circuit diagrams of an NPN three-wire magnetic switch and a PNP three-wire magnetic switch are respectively shown. The loads of the NPN three-wire magnetic switch are respectively connected to the power supply terminal VDD and the output terminal OUT of the drive chip 2. One end of the load of the PNP three-wire magnetic switch is connected to the output terminal OUT of the drive chip 2, and the other end is grounded. This is because the output signal of the NPN three-wire magnetic switch is lower than that of the PNP three-wire magnetic switch to respectively adapt to the usage scenarios with different levels of level signals.

[0027] Specifically, as Figure 1As shown, the output terminal VOUT of the magnetic induction chip 1 is connected to the input terminal IN of the drive chip 2, and the power supply interface VDD of the magnetic induction chip 1 is connected to one of the output interfaces VOUT of the drive chip 2. The drive chip 2 supplies power to the magnetic induction chip 1 to ensure the power supply consistency of the two chips. The output terminal VOUT of the drive chip 2 connected to the power supply terminal VDD of the magnetic induction chip 1 is internally connected with a voltage stabilizing circuit, and the voltage stabilizing circuit ensures the stability of the power supply voltage when the drive chip 2 supplies power to the magnetic induction chip 1, ensuring circuit safety. The voltage stabilizing circuit can specifically be a voltage stabilizing diode or a transistor connected in series with the output terminal VOUT of the drive chip 2, or it can also be other forms of voltage stabilizing circuits. In addition, the power supply terminals VDD of the drive chip 2 and the magnetic induction chip 1 are respectively connected with a second pull-down capacitor C2 and a first pull-down capacitor C1, which are also used to stabilize the power supply voltage and serve as decoupling capacitors to avoid the impact on the power supply terminals VDD of the drive chip 2 and the magnetic induction chip 1 when the drive chip 2 switches frequently.

[0028] During the wiring and use of the magnetic switch, there may be situations of wrong wiring (wrong connection of positive and negative poles, wrong connection of output wires) or overcurrent and overload, especially in the case of poor power supply or wiring, which not only affects the user experience but also may damage electrical equipment. To improve the stability and safety of the electrical system where the magnetic switch is located. As Figure 2 shown, the drive chip 2 includes a signal path switch and an overcurrent and overload detection circuit; the signal path switch is used to send load current or load voltage to the load based on the control signal; the overcurrent and overload detection circuit includes a load voltage detection circuit, a comparison circuit, and a logic circuit; the load voltage detection circuit is used to detect the load voltage and send the load voltage to the comparison circuit; the comparison circuit compares the magnitudes of the load voltage and the reference voltage vref, and inputs the comparison result into the logic circuit; the logic circuit is connected to the signal path switch, and the logic circuit is used to send an open-circuit signal to the signal path switch when the time when the load voltage is greater than the reference voltage vref exceeds the overload time. The logic circuit judges that the load voltage is greater than the reference voltage verf for a period of time and then opens the signal path switch, avoiding frequent pauses of the magnetic switch caused by individual abnormal data, which affects the normal operation of the magnetic switch and damages the internal chip of the magnetic switch. At the same time, the frequent pauses of the magnetic switch also increase the manual maintenance cost and cannot guarantee the work efficiency.

[0029] Specifically, the load voltage detection circuit includes a current detection resistor, which is connected to the load and used to detect the load current and convert the load current into the load voltage. The load voltage is obtained through the load current passing through the current detection resistor, with high stability, more reliable detection results, and the resistance value of the current detection resistor being easy to adjust, capable of adapting to different voltage detection requirements.

[0030] The comparison circuit includes a comparator. Two input terminals of the comparator are respectively connected to the output terminal of the load voltage detection circuit and the reference voltage Vref. The output terminal of the comparator is connected to the input terminal of the logic circuit. One end of the comparator connected to the reference voltage Vref can be externally connected with a resistor to adjust the value of the reference voltage Vref. The comparator sends different level signals to the logic circuit based on the comparison result between the load voltage and the reference voltage Vref.

[0031] When the first timer in the logic circuit receives the level signal corresponding to the load voltage being higher than the reference voltage Vref, it starts timing and stops timing until the level signal changes. When the timing time exceeds the overload time, the logic circuit sends an open circuit signal to the signal path switch. For example, when the load voltage is less than or equal to the reference voltage Vref, the comparator sends a low level signal to the first timer in the logic circuit. When the load voltage is higher than the reference voltage Vref, the comparator sends a high level signal to the first timer in the logic circuit. The first timer starts timing when it first receives the high level signal and stops timing until the timer receives the low level signal again. Whether the timing time exceeds the overload time is judged by another comparator or other comparison circuits, and when it exceeds, an open circuit signal is sent to the signal path switch. The first timer is cleared after each timing.

[0032] In addition, the logic circuit is also connected to an error reporting circuit, and the error reporting circuit is connected to an indicator light D1 externally connected to the driving chip 2. When the logic circuit sends the open circuit signal, it also sends an error reporting signal to the error reporting circuit. After receiving the error reporting signal, the error reporting circuit sends a flashing signal to the indicator light D1. The indicator light D1 is an LED or other type of warning light, used to remind the staff that the magnetic switch is in an abnormal state at this time. The error reporting circuit provides different voltages to the indicator light D1 based on the received signal. For example, when the indicator light D1 is an LED, after receiving the error reporting signal, the error reporting circuit outputs a constant voltage that can turn on the indicator light D1 to make the indicator light D1 flash.

[0033] In order to enable the magnetic switch to automatically recover when it is disconnected due to individual abnormal conditions and reduce the manual operation process of the staff, a second timer is included in the logic circuit, and the second timer starts timing when the error signal is sent; when the logic circuit determines that the timing time exceeds the overcurrent protection time, it sends an open-circuit signal to the signal path switch, so that the magnetic switch automatically recovers after being open for a period of time, and sends a stop flashing signal to the indicator light D1 through the error circuit. At this time, the voltage output by the error circuit to the LED light cannot conduct the LED light, and the LED light stops flashing. After each timing of the second timer is completed, it is cleared, and the timing times of the first timer and the second timer do not overlap, and the same timer can be used to implement the timing functions of the first timer and the second timer.

[0034] Due to the automatic recovery function of the magnetic switch, when the magnetic switch is used for a long time and the number of on-off times reaches a certain number, it will cause certain damage to the magnetic switch, and the magnetic switch needs to be replaced and maintained; in addition, the large number of on-off times may also be due to the long duration of abnormal conditions. After the magnetic switch automatically recovers, it is immediately disconnected again, and the magnetic switch also needs to be replaced and maintained in time. Therefore, a counter is also included in the logic circuit. The counter counts the number of times the open-circuit signal is sent. When the number exceeds the number threshold, the second timer is reset to zero and stops timing, and the indicator light continues to flash.

[0035] Although several specific implementation details are included in the above description, these should not be construed as limiting the scope of this specification. Certain features described in the context of separate embodiments can also be implemented in combination in a single implementation. Conversely, the various features described in the context of a single implementation can also be implemented separately or in any suitable sub-combination in multiple implementations.

[0036] Although the subject matter has been described in language specific to structural features and / or methodological logical acts, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. On the contrary, the specific features and acts described above are merely example forms of implementing the claims.

[0037] The embodiments of this specification have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary skilled persons in the technical field to understand the embodiments disclosed herein.

Claims

1. A magnetic switch, characterized in that: The invention comprises a magnetic induction chip (1) and a driving chip (2); the magnetic induction chip (1) senses a change in a magnetic field and sends a control signal to the driving chip (2) based on the change in the magnetic field; the driving chip (2) sends a load current or a load voltage to a load based on the control signal; the driving chip (2) comprises a signal path switch and an overload and overcurrent detection circuit; the signal path switch is used to send a load current or a load voltage to a load based on the control signal; the overload and overcurrent detection circuit comprises a load voltage detection circuit, a comparison circuit and a logic circuit; the load voltage detection circuit is used to detect the load voltage and send the load voltage to the comparison circuit; The comparison circuit compares the load voltage and the reference voltage and inputs the comparison result into the logic circuit; the logic circuit is connected to the signal path switch, and the logic circuit is used to send a disconnect signal to the signal path switch when the load voltage is greater than the reference voltage for a period exceeding the overload time.

2. The magnetic switch according to claim 1, characterized in that: The logic circuit is also connected to an error reporting circuit, and the error reporting circuit is connected to an indicator light externally connected to the driver chip (2); when the logic circuit sends the disconnection signal, it also sends an error reporting signal to the error reporting circuit, and after receiving the error reporting signal, the error reporting circuit sends a flashing signal to the indicator light.

3. The magnetic switch according to claim 2, characterized in that: The logic circuit includes a second timer, which starts timing when the error signal is sent; when the logic circuit determines that the timing time exceeds the overcurrent protection time, it sends an open circuit signal to the signal path switch, and sends a stop flashing signal to the indicator light through the error circuit.

4. The magnetic switch according to claim 3, characterized in that: The logic circuit also includes a counter, which counts the number of times the disconnection signal is sent. When the number exceeds a threshold, the timer is reset to zero and stops timing.

5. The magnetic switch according to claim 1, characterized in that: The load voltage detection circuit includes a current detection resistor, which is connected to the load and is used to detect the load current and convert the load current into the load voltage.

6. The magnetic switch according to claim 5, characterized in that: The comparison circuit includes a comparator, wherein two input ends of the comparator are respectively connected to the output end of the load voltage detection circuit and the reference voltage, and the output end of the comparator is connected to the input end of the logic circuit; the comparator sends different level signals to the logic circuit based on the comparison result of the load voltage and the reference voltage; the first timer in the logic circuit starts timing when it receives a level signal corresponding to the load voltage being higher than the reference voltage, and stops when the level signal changes, and when the timing time exceeds the overload time, the logic circuit sends a disconnection signal to the signal path switch.

7. The magnetic switch according to claim 6, characterized in that: The port of the comparator for inputting the reference voltage is externally connected to an adjustable resistor.

8. The magnetic switch according to claim 1, characterized in that: The output end of the magnetic induction chip (1) is connected to the input end of the drive chip (2), and the power supply end of the magnetic induction chip is connected to one of the output ends of the drive chip (2).

9. The magnetic switch according to claim 8, characterized in that: The power supply terminals of the driving chip (2) and the magnetic induction chip (1) are both connected to pull-down capacitors.

10. The magnetic switch according to claim 8, characterized in that The output interface of the driving chip (2) connected to the power supply terminal of the magnetic induction chip (1) is internally connected to a voltage stabilizing circuit.

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