A high-low level control circuit for simulating the behavior of a self-resetting normally closed switch

Abstract

This utility model discloses a high / low level control circuit for simulating the behavior of a self-resetting normally closed switch, relating to the field of high / low level control. The normally open switch module controls the on / off state of a transistor driving module. The transistor driving module includes a transistor that conducts when the normally open switch module is open and cuts off when it is closed. The output terminal is electrically connected to the transistor driving module and also electrically connected to a power supply module via a voltage divider module, for outputting a high or low level signal to the load circuit. The voltage divider module controls the output voltage of the output terminal based on the on / off state of the normally open switch module. When the normally open switch module is open, the transistor conducts, and the output terminal outputs a low level; when the normally open switch module is closed, the transistor cuts off, and the output terminal outputs a high level. This utility model implements a self-resetting normally closed function based on electronic components.

Description

Technical Field

[0001] This utility model relates to the field of high and low level control, and in particular to a high and low level control circuit for simulating the behavior of a self-resetting normally closed switch. Background Technology

[0002] With the rapid development of automotive electrification, the number of electronic components used is growing exponentially, and switches, as a key component, are widely used in various control systems. Traditional solutions often use self-resetting normally closed mechanical switches conforming to the AEC-Q series standard to control circuit on / off states. These switches maintain a closed conduction state when not in operation and open when pressed. However, this type of switch has several limitations: firstly, the selection of automotive-grade normally closed switches is limited, and the package type (such as SMD-6.2×6.2mm) is difficult to meet diverse PCB layout requirements; secondly, the procurement cost is high, with a premium of 35%-60% compared to conventional components, and the supply cycle is unstable; thirdly, the mechanical contact life is generally less than 50,000 cycles, making it difficult to meet the long-term reliability requirements of high-frequency operation scenarios. Utility Model Content

[0003] To achieve a self-resetting normally closed function based on electronic components, this invention proposes a high-low level control circuit for simulating the behavior of a self-resetting normally closed switch, comprising:

[0004] The power supply module, normally open switch module, voltage divider module, transistor driver module, and output terminal are included.

[0005] The power module is used to output the power supply voltage;

[0006] The normally open switch module is connected to the power supply module through a voltage divider module and is used to control the on / off state of the transistor drive module.

[0007] The transistor driving module includes a transistor for conducting when the normally open switch module is open and cutting off when it is closed;

[0008] The output terminal is electrically connected to the transistor driving module and also electrically connected to the power supply module through the voltage divider module, and is used to output a high-level or low-level signal to the load circuit.

[0009] The voltage divider module consists of two series resistors and is used to control the output voltage of the output terminal based on the opening and closing state of the normally open switch module.

[0010] Specifically, when the normally open switch module is open, the transistor is turned on, and the output terminal outputs a low level; when the normally open switch module is closed, the transistor is turned off, and the output terminal outputs a high level.

[0011] Furthermore, the normally open switch module includes a normally open switch SW1; the voltage divider module includes a first resistor R1 and a second resistor R2.

[0012] Furthermore, the transistor driving module includes NPN type transistors;

[0013] The base of the NPN transistor is connected to one end of the second resistor R2 and one end of the normally open switch SW1, and the emitter is connected to the other end of the normally open switch SW1 and then grounded; the other end of the second resistor R2 is connected to one end of the first resistor R1 and the collector of the NPN transistor and then connected to the load circuit; the other end of the first resistor R1 is connected to the power module VCC.

[0014] Furthermore, when the normally open switch SW1 is in the open state:

[0015] The base of the NPN transistor is connected to the power module VCC through the first resistor R1 and the second resistor R2. At this time, the base voltage is greater than the conduction threshold of the NPN transistor, and the NPN transistor is in the conduction state. The power supply voltage output by the power module VCC is grounded through the first conduction path and the second conduction path, and the output terminal outputs a low level.

[0016] Furthermore, when the normally open switch SW1 is in the closed state:

[0017] The base voltage of the NPN transistor is less than the conduction threshold of the NPN transistor, so the NPN transistor is in the off state. The power supply voltage output by the power module VCC is grounded after passing through the first resistor R1, the second resistor R2, and the normally open switch SW1 in sequence. At this time, the collector of the NPN transistor is pulled high, and the output terminal outputs a high level.

[0018] Furthermore, the power supply voltage output by the power module VCC is grounded through the first conduction path, specifically: the power supply voltage output by the power module VCC is grounded after passing through the first resistor R1, the collector and emitter of the NPN transistor in sequence.

[0019] Furthermore, the power supply voltage output by the power module VCC is grounded through the second conduction path, specifically: the power supply voltage output by the power module VCC is grounded after passing through the first resistor R1, the second resistor R2, and the base and emitter of the NPN transistor in sequence.

[0020] Furthermore, the transistor driving module includes PNP type transistors;

[0021] The base of the PNP transistor is connected to one end of the second resistor R2 and one end of the normally open switch SW1, and the collector is connected to the other end of the second resistor R2 and then grounded; the other end of the normally open switch SW1 is connected to one end of the first resistor R1 and the emitter of the PNP transistor and then connected to the load circuit; the other end of the first resistor R1 is connected to the power module VCC.

[0022] Furthermore, when the normally open switch SW1 is in the open state:

[0023] The base of the PNP transistor is pulled low to GND through the second resistor R2. At this time, the base voltage is less than the emitter voltage, and the PNP transistor is in the conducting state. The power supply voltage output by the power module VCC passes through the load circuit, the emitter and collector of the PNP transistor in sequence and then to ground, and the output terminal outputs a low level.

[0024] Furthermore, when the normally open switch SW1 is in the closed state:

[0025] When the base of a PNP transistor is pulled high to near VCC, the PNP transistor is in the off state, and the output terminal outputs a high level.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects:

[0027] (1) In this utility model, the normally open switch module is connected to the power supply module through a voltage divider module to control the on / off state of the transistor drive module; the transistor drive module includes a transistor for conducting when the normally open switch module is open and cutting off when it is closed; the output terminal is electrically connected to the transistor drive module and also electrically connected to the power supply module through the voltage divider module to output a high-level or low-level signal to the load circuit; the voltage divider module consists of two series resistors and is used to control the output voltage of the output terminal based on the opening and closing state of the normally open switch module; when the normally open switch module is open, the transistor is on and the output terminal outputs a low level; when the normally open switch module is closed, the transistor is off and the output terminal outputs a high level; this utility model avoids dependence on a self-resetting normally closed switch with a specific package form through modular circuit design and realizes the self-resetting normally closed function based on electronic components.

[0028] (2) Compared to automotive-grade self-resetting normally closed mechanical switches, the electronic components used in this invention are of lower cost and do not have the 35%-60% premium issue. Furthermore, the use of standardized electronic components makes the supply cycle more stable and reduces supply chain risks. Modular circuit design also enables mass production and optimizes supply chain management, further reducing overall costs.

[0029] (3) This utility model is based on the design of electronic components: for example, using electronic components such as transistors for switch control, eliminating the problem of mechanical contact wear, significantly improving the reliability and service life of the system, and reducing maintenance and replacement costs.

[0030] (4) This utility model abandons the traditional mechanical switch and uses electronic components that conform to the AEC-Q series standard to achieve a self-resetting normally closed function, ensuring the reliability and stability of the entire circuit in the automotive environment. This enables the circuit to work normally in harsh environments such as high temperature, vibration, and humidity. Attached Figure Description

[0031] Figure 1 This is a high / low level control circuit diagram of Embodiment 1 of this utility model;

[0032] Figure 2 This is a high / low level control circuit diagram for Embodiment 2 of this utility model. Detailed Implementation

[0033] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0034] Example 1

[0035] To achieve a self-resetting normally closed function based on electronic components, this invention proposes a high-low level control circuit for simulating the behavior of a self-resetting normally closed switch, comprising:

[0036] The power supply module, normally open switch module, voltage divider module, transistor driver module, and output terminal are included.

[0037] The power module is used to output the power supply voltage;

[0038] The normally open switch module is connected to the power supply module through a voltage divider module and is used to control the on / off state of the transistor drive module.

[0039] The transistor driving module includes a transistor for conducting when the normally open switch module is open and cutting off when it is closed;

[0040] The output terminal is electrically connected to the transistor driving module and also electrically connected to the power supply module through the voltage divider module, and is used to output a high-level or low-level signal to the load circuit.

[0041] The voltage divider module consists of two series resistors and is used to control the output voltage of the output terminal based on the opening and closing state of the normally open switch module.

[0042] Specifically, when the normally open switch module is open, the transistor is turned on, and the output terminal outputs a low level; when the normally open switch module is closed, the transistor is turned off, and the output terminal outputs a high level.

[0043] The normally open switch module includes a normally open switch SW1; the voltage divider module includes a first resistor R1 (resistance range 1kΩ-10kΩ) and a second resistor R2 (4.7kΩ-47kΩ).

[0044] The transistor driving module contains NPN type transistors;

[0045] like Figure 1 As shown, the base of the NPN transistor is connected to one end of the second resistor R2 and one end of the normally open switch SW1, and the emitter is connected to the other end of the normally open switch SW1 and then grounded; the other end of the second resistor R2 is connected to one end of the first resistor R1 and the collector of the NPN transistor, and then connected to the load circuit; the other end of the first resistor R1 is connected to the power module VCC.

[0046] When normally open switch SW1 is in the open state:

[0047] The base of the NPN transistor is connected to the power module VCC through the first resistor R1 and the second resistor R2. At this time, the base voltage is greater than the conduction threshold of the NPN transistor, and the NPN transistor is in the conduction state. The power supply voltage output by the power module VCC is grounded through the first conduction path and the second conduction path, and the output terminal outputs a low level.

[0048] The power supply voltage output by the power module VCC is grounded through the first conduction path, specifically: the power supply voltage output by the power module VCC is grounded after passing through the first resistor R1, the collector and emitter of the NPN transistor in sequence.

[0049] The power supply voltage output by the power module VCC is grounded through the second conduction path. Specifically, the power supply voltage output by the power module VCC is grounded after passing through the first resistor R1, the second resistor R2, and the base and emitter of the NPN transistor in sequence.

[0050] When the normally open switch SW1 is in the open state, specifically:

[0051] Base voltage: The base of the NPN transistor is connected to the power supply module VCC through the second resistor R2 and the first resistor R1. At this time, since no current flows through the normally open switch SW1 (because it is open), the base voltage is close to the power supply voltage VCC.

[0052] Operating state of an NPN transistor: Because the base voltage exceeds the NPN transistor's turn-on threshold (typically 0.7V), the NPN transistor meets the turn-on condition and enters the turn-on state. In the turn-on state, the NPN transistor allows current to flow from the collector to the emitter.

[0053] Current path:

[0054] The first conduction path: The power supply voltage output from the power module VCC passes sequentially through the first resistor R1, the collector and emitter of the NPN transistor, and then to ground. This path allows the current in the load circuit to flow smoothly, and the output voltage is close to ground potential (low level).

[0055] The second conduction path: The power supply voltage output from the power module VCC passes sequentially through the first resistor R1, the second resistor R2, and the base and emitter of the NPN transistor before being grounded. This path ensures that there is sufficient current at the base to maintain the transistor's conduction state.

[0056] Therefore, in this state, the output terminal outputs a low-level signal.

[0057] When the normally open switch SW1 is in the closed state:

[0058] The base voltage of the NPN transistor is less than the conduction threshold of the NPN transistor, so the NPN transistor is in the off state. The power supply voltage output by the power module VCC is grounded after passing through the first resistor R1, the second resistor R2, and the normally open switch SW1 in sequence. At this time, the collector of the NPN transistor is pulled high, and the output terminal outputs a high level.

[0059] When the normally open switch SW1 is in the closed state, specifically:

[0060] Base voltage: When the normally open switch SW1 is closed, the base of the NPN transistor is directly grounded through the normally open switch SW1. At this time, the base voltage is pulled down to near ground potential (0V), which is far below the conduction threshold of the NPN transistor.

[0061] Operating state of an NPN transistor: Because the base voltage is less than the NPN transistor's turn-on threshold, the NPN transistor no longer meets the turn-on condition and enters the off state. In the off state, the NPN transistor blocks the path of current flowing from the collector to the emitter.

[0062] Current path: The power supply voltage output from the power module VCC passes through the first resistor R1, the second resistor R2, and the normally open switch SW1 before reaching ground. Because the NPN transistor is cut off, the power supply voltage cannot flow to ground through the transistor. Instead, the power supply voltage acts directly on the output terminal through the first resistor R1, making the output voltage close to the power supply voltage VCC (high level).

[0063] Therefore, in this state, the output terminal outputs a high-level signal.

[0064] The behavior of a traditional self-resetting normally closed switch is as follows: In its normal state (not pressed), the switch is closed, and current can flow through the load; when the switch is pressed, the switch opens, and the current is cut off; after the button is released, the switch automatically returns to the closed state, and current flows through the load again. This behavior allows the normally closed switch to remain conductive when no external force is applied, and to temporarily disconnect when pressed and automatically reset after being released.

[0065] In this configuration, if the output is connected to the side closest to ground, it will output a low level when normally (not pressed), equivalent to an external switch being closed and conducting; when pressed, it will output a high level, equivalent to an external switch being open. However, the specific output level setting depends on the circuit design.

[0066] This invention utilizes circuit design to simulate the logic characteristics of a normally closed switch at the output terminal by employing the operational behavior of a normally open mechanical switch. Specifically, when the switch is not pressed, the circuit design causes the output terminal to output a low level, equivalent to the external switch being closed and conducting; when the switch is pressed, the circuit design causes the output terminal to output a high level, equivalent to the external switch being open; after the switch is released, the circuit output returns to a low level, equivalent to the external switch automatically resetting and closing.

[0067] In this way, this invention not only achieves electronic simulation of the behavior of normally closed switches, but also provides greater flexibility and reliability. This electronic simulation scheme avoids reliance on self-resetting normally closed switches with specific package forms, uses standardized electronic components, reduces costs, and improves system reliability and lifespan. It is applicable to various automotive electronic control units and other application scenarios, providing a reliable and flexible alternative.

[0068] Example 2

[0069] To achieve a self-resetting normally closed function based on electronic components, this invention proposes a high-low level control circuit for simulating the behavior of a self-resetting normally closed switch, comprising:

[0070] The power supply module, normally open switch module, voltage divider module, transistor driver module, and output terminal are included.

[0071] The power module is used to output the power supply voltage;

[0072] The normally open switch module is connected to the power supply module through a voltage divider module and is used to control the on / off state of the transistor drive module.

[0073] The transistor driving module includes a transistor for conducting when the normally open switch module is open and cutting off when it is closed;

[0074] The output terminal is electrically connected to the transistor driving module and also electrically connected to the power supply module through the voltage divider module, and is used to output a high-level or low-level signal to the load circuit.

[0075] The voltage divider module consists of two series resistors and is used to control the output voltage of the output terminal based on the opening and closing state of the normally open switch module.

[0076] Specifically, when the normally open switch module is open, the transistor is turned on, and the output terminal outputs a low level; when the normally open switch module is closed, the transistor is turned off, and the output terminal outputs a high level.

[0077] The normally open switch module includes a normally open switch SW1; the voltage divider module includes a first resistor R1 and a second resistor R2.

[0078] The transistor driving module contains PNP type transistors;

[0079] like Figure 2 As shown, the base of the PNP transistor is connected to one end of the second resistor R2 and one end of the normally open switch SW1, and the collector is connected to the other end of the second resistor R2 and then grounded; the other end of the normally open switch SW1 is connected to one end of the first resistor R1 and the emitter of the PNP transistor, and then connected to the load circuit; the other end of the first resistor R1 is connected to the power module VCC.

[0080] When normally open switch SW1 is in the open state:

[0081] The base of the PNP transistor is pulled low to GND through the second resistor R2. At this time, the base voltage is less than the emitter voltage, and the PNP transistor is in the on state. The power supply voltage output from the power module VCC passes through the load circuit, the emitter and collector of the PNP transistor, and then to ground, resulting in a low-level output. Specifically:

[0082] Base voltage: The base of the PNP transistor is connected to ground (GND) through the second resistor R2, thus pulling the base voltage down to near 0V. At this time, the emitter is connected to the power supply module and the load circuit through the first resistor R1, so the emitter voltage is VCC.

[0083] Operating state of a PNP transistor: Because the base voltage is less than the emitter voltage (i.e., base voltage ≈ 0V, emitter voltage = VCC), the PNP transistor meets the conduction condition and enters the conduction state. In the conduction state, the PNP transistor allows current to flow from the emitter to the collector.

[0084] Current path: The power supply voltage output from the power module VCC passes sequentially through the first resistor R1, the load circuit, and the emitter and collector of the PNP transistor before being grounded. Because the PNP transistor is conducting, current flows smoothly through the load circuit, and the output voltage is close to ground potential (low level). Therefore, in this state, a low-level signal is output.

[0085] When the normally open switch SW1 is in the closed state:

[0086] When the base of a PNP transistor is pulled high to near VCC, the PNP transistor is in the off state, and the output terminal outputs a high level. Specifically:

[0087] Base voltage: When the normally open switch SW1 is closed, the base voltage of the PNP transistor is pulled up to near the power supply voltage VCC. At this time, the base voltage is close to the emitter voltage (both are close to VCC).

[0088] Operating state of a PNP transistor: As the base voltage approaches the emitter voltage, the PNP transistor no longer meets the conduction condition and enters the cutoff state. In the cutoff state, the PNP transistor blocks the path of current flowing from the emitter to the collector.

[0089] Current path: Because the PNP transistor is cut off, the power supply voltage output from the power module VCC cannot flow to ground through the PNP transistor. Instead, the power supply voltage acts directly on the output terminal through the first resistor R1, making the output terminal voltage close to the power supply voltage VCC (high level). Therefore, in this state, the output terminal outputs a high-level signal.

[0090] In this invention, the normally open switch module is connected to the power supply module via a voltage divider module to control the on / off state of the transistor drive module. The transistor drive module includes a transistor that conducts when the normally open switch module is open and cuts off when it is closed. The output terminal is electrically connected to the transistor drive module and also to the power supply module via the voltage divider module, for outputting a high-level or low-level signal to the load circuit. The voltage divider module consists of two series resistors and controls the output voltage of the output terminal based on the on / off state of the normally open switch module. When the normally open switch module is open, the transistor conducts, and the output terminal outputs a low level. When the normally open switch module is closed, the transistor cuts off, and the output terminal outputs a high level. This invention avoids dependence on self-resetting normally closed switches with specific packaging forms through modular circuit design, and realizes the self-resetting normally closed function based on electronic components.

[0091] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0092] Furthermore, in this utility model, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0093] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0094] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

Claims

1. A high / low level control circuit for simulating the behavior of a self-resetting normally closed switch, characterized in that, include: The power supply module, normally open switch module, voltage divider module, transistor driver module, and output terminal are included. The power module is used to output the power supply voltage; The normally open switch module is connected to the power supply module through a voltage divider module and is used to control the on / off state of the transistor drive module. The transistor driving module includes a transistor for conducting when the normally open switch module is open and cutting off when it is closed; The output terminal is electrically connected to the transistor driving module and also electrically connected to the power supply module through the voltage divider module, and is used to output a high-level or low-level signal to the load circuit. The voltage divider module consists of two series resistors and is used to control the output voltage of the output terminal based on the opening and closing state of the normally open switch module. Specifically, when the normally open switch module is open, the transistor is turned on, and the output terminal outputs a low level; when the normally open switch module is closed, the transistor is turned off, and the output terminal outputs a high level.

2. The high / low level control circuit for simulating the behavior of a self-resetting normally closed switch according to claim 1, characterized in that, The normally open switch module includes a normally open switch SW1; the voltage divider module includes a first resistor R1 and a second resistor R2.

3. The high / low level control circuit for simulating the behavior of a self-resetting normally closed switch according to claim 2, characterized in that, The transistor driving module contains NPN type transistors; The base of the NPN transistor is connected to one end of the second resistor R2 and one end of the normally open switch SW1, and the emitter is connected to the other end of the normally open switch SW1 and then grounded; the other end of the second resistor R2 is connected to one end of the first resistor R1 and the collector of the NPN transistor and then connected to the load circuit; the other end of the first resistor R1 is connected to the power module VCC.

4. A high / low level control circuit for simulating the behavior of a self-resetting normally closed switch according to claim 3, characterized in that, When normally open switch SW1 is in the open state: The base of the NPN transistor is connected to the power module VCC through the first resistor R1 and the second resistor R2. At this time, the base voltage is greater than the conduction threshold of the NPN transistor, and the NPN transistor is in the conduction state. The power supply voltage output by the power module VCC is grounded through the first conduction path and the second conduction path, and the output terminal outputs a low level.

5. A high / low level control circuit for simulating the behavior of a self-resetting normally closed switch according to claim 4, characterized in that, When the normally open switch SW1 is in the closed state: The base voltage of the NPN transistor is less than the conduction threshold of the NPN transistor, so the NPN transistor is in the off state. The power supply voltage output by the power module VCC is grounded after passing through the first resistor R1, the second resistor R2, and the normally open switch SW1 in sequence. At this time, the collector of the NPN transistor is pulled high, and the output terminal outputs a high level.

6. A high / low level control circuit for simulating the behavior of a self-resetting normally closed switch according to claim 4, characterized in that, The power supply voltage output by the power module VCC is grounded through the first conduction path, specifically: the power supply voltage output by the power module VCC is grounded after passing through the first resistor R1, the collector and emitter of the NPN transistor in sequence.

7. A high / low level control circuit for simulating the behavior of a self-resetting normally closed switch according to claim 4, characterized in that, The power supply voltage output by the power module VCC is grounded through the second conduction path. Specifically, the power supply voltage output by the power module VCC is grounded after passing through the first resistor R1, the second resistor R2, and the base and emitter of the NPN transistor in sequence.

8. A high / low level control circuit for simulating the behavior of a self-resetting normally closed switch according to claim 2, characterized in that, The transistor driving module contains PNP type transistors; The base of the PNP transistor is connected to one end of the second resistor R2 and one end of the normally open switch SW1, and the collector is connected to the other end of the second resistor R2 and then grounded; the other end of the normally open switch SW1 is connected to one end of the first resistor R1 and the emitter of the PNP transistor and then connected to the load circuit; the other end of the first resistor R1 is connected to the power module VCC.

9. A high / low level control circuit for simulating the behavior of a self-resetting normally closed switch according to claim 8, characterized in that, When normally open switch SW1 is in the open state: The base of the PNP transistor is pulled low to GND through the second resistor R2. At this time, the base voltage is less than the emitter voltage, and the PNP transistor is in the conducting state. The power supply voltage output by the power module VCC passes through the load circuit, the emitter and collector of the PNP transistor in sequence and then to ground, and the output terminal outputs a low level.

10. A high / low level control circuit for simulating the behavior of a self-resetting normally closed switch according to claim 9, characterized in that, When the normally open switch SW1 is in the closed state: When the base of a PNP transistor is pulled high to near VCC, the PNP transistor is in the off state, and the output terminal outputs a high level.

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