Electronic relay circuit with latching function based on P-MOS (P-Metal Oxide Semiconductor) transistor

Abstract

The embodiment of the utility model discloses a P-MOS tube-based electronic relay circuit with a latch function, which comprises a control unit, a D-type trigger and a P-MOS tube unit, and is characterized in that the P-MOS tube unit is connected with an electronic relay; the control unit is used for outputting a control signal; the D-type trigger is used for outputting a level signal according to the control signal; and the P-MOS tube unit is used for conducting or cutting off according to the level signal so as to realize closing or opening of the electronic relay. By implementing the circuit provided by the embodiment of the utility model, the limitation of the traditional mechanical relay on space limitation and function requirements can be effectively solved.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic relays, in particular to an electronic relay circuit with a latching function based on a P-MOS tube. Background Art

[0002] In the design of built-in relay circuits, if the product requires a relay that can carry a high power of 3A, but is restricted by the limited space of the PCB board and the structural limitations of the product appearance design, traditional mechanical relays may not be able to meet the needs. Mechanical relays are usually large in size and high in height, which poses a challenge to the miniaturization of the overall size of the product.

[0003] In addition, in circuit design, if the relay is required to have a latching function to ensure that the relay can maintain its previous state after the external power supply is cut off, restarted or powered on again, traditional mechanical relays may not be able to meet the requirements.

[0004] Therefore, it is necessary to design a new circuit to effectively solve the limitations of traditional mechanical relays in terms of space constraints and functional requirements. Utility Model Content

[0005] The utility model aims to overcome the defects of the prior art and provide an electronic relay circuit with a latching function based on a P-MOS tube.

[0006] In order to solve the above technical problems, the purpose of the utility model is achieved through the following technical solutions: providing an electronic relay circuit with a latching function based on a P-MOS tube, comprising: a control unit, a D-type trigger and a P-MOS tube unit, wherein the P-MOS tube unit is connected to the electronic relay; the control unit is used to output a control signal; the D-type trigger is used to output a level signal according to the control signal; the P-MOS tube unit is used to conduct or cut off according to the level signal to realize the closing or opening of the electronic relay.

[0007] A further technical solution is as follows: the D-type trigger includes a single-channel D-type trigger U11.

[0008] A further technical solution is as follows: the single-channel D-type trigger U11 is connected to a pull-up resistor R46, and the single-channel D-type trigger U11 is connected to a pull-down resistor R157 and a pull-down resistor R54.

[0009] Its further technical solution is: the single-channel D-type trigger U11 is connected to an RC filtering circuit, and the RC filtering circuit includes a current limiting debugging resistor R57, a current limiting debugging resistor R153, a ground capacitor C73, and a ground capacitor C84; one end of the ground capacitor C73 is grounded, and the other end of the ground capacitor C73 is connected between the current limiting debugging resistor R57 and the single-channel D-type trigger U11; one end of the ground capacitor C84 is grounded, and the other end of the ground capacitor C84 is connected between the current limiting debugging resistor R153 and the single-channel D-type trigger U11.

[0010] A further technical solution is as follows: the single-channel D-type trigger U11 is further connected to a filter capacitor C66 and a bypass filter capacitor C65.

[0011] A further technical solution is as follows: the P-MOS tube unit includes a P-MOS tube T14 and a P-MOS tube T8, and the P-MOS tube T14 and the P-MOS tube T8 are connected to the single-channel D-type trigger U11 and the electronic relay respectively.

[0012] A further technical solution is as follows: a transistor Q29 and a transistor Q26 are sequentially connected between the P-MOS transistor T14 and the single-channel D-type trigger U11.

[0013] A further technical solution is as follows: a transistor Q33 and a transistor Q32 are sequentially connected between the P-MOS tube T8 and the single-channel D-type trigger U11.

[0014] Its further technical solution is: the current limiting voltage divider resistor R111 and the current limiting voltage divider resistor R104 are connected in sequence between the P-MOS tube T14 and the transistor Q29; the current limiting voltage divider resistor R266 and the current limiting voltage divider resistor R126 are connected in sequence between the P-MOS tube T8 and the transistor Q33.

[0015] A further technical solution is as follows: the current limiting voltage dividing resistor R111 is connected in parallel with a voltage zener diode D33; the current limiting voltage dividing resistor R266 is connected in parallel with a voltage zener diode D60.

[0016] The beneficial effects of the utility model compared with the prior art are as follows: the utility model provides a control unit, a D-type trigger and a P-MOS tube unit. The P-MOS tube unit itself is small in size, does not require mechanical parts, is not easily subject to wear and fatigue, has a fast turn-on and cut-off speed, a short response time, and lower power consumption. It can save energy and reduce heating problems, and effectively solve the limitations of traditional mechanical relays in terms of space constraints and functional requirements.

[0017] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic block diagram of an electronic relay circuit with a latching function based on a P-MOS tube provided in an embodiment of the utility model;

[0020] Figure 2 A specific circuit schematic diagram of an electronic relay circuit with a latching function based on a P-MOS tube provided in an embodiment of the utility model;

[0021] Description of the symbols in the figure:

[0022] 10. Control unit; 20. D-type trigger; 30. P-MOS tube unit. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0025] It should also be understood that the terms used in this utility model specification are only for the purpose of describing specific embodiments and are not intended to limit the utility model. As used in this utility model specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0026] It should be further understood that the term “and / or” used in the present specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0027] See also Figure 1, Figure 1 The schematic block diagram of the electronic relay circuit with latching function based on P-MOS tube provided in the embodiment of the utility model can be used in the opening or closing process of the electronic relay to effectively solve the limitations of traditional mechanical relays in terms of space constraints and functional requirements.

[0028] See also Figure 1 The above-mentioned electronic relay circuit with latching function based on P-MOS tube includes: a control unit, a D-type trigger and a P-MOS tube unit, the P-MOS tube unit is connected to the electronic relay; the control unit is used to output a control signal; the D-type trigger is used to output a level signal according to the control signal; the P-MOS tube unit is used to conduct or cut off according to the level signal to realize the closing or opening of the electronic relay.

[0029] Specifically, the control unit sends a signal to control the D-flip-flop to output high and low levels to control the on and off of the P-MOS tube, thereby realizing the on and off function of the relay of pin 30 and pin 87 / 87a. The process can be described in detail as follows:

[0030] The control unit generates a control signal, which can be sent out through a digital output port or a specific control interface. The generation of control signals is usually based on the logical control requirements of the system, such as turning on or off a relay according to specific conditions.

[0031] After the control signal is processed by the necessary circuits, it is transmitted to the D-type flip-flop. The D-type flip-flop is a digital logic circuit that can generate corresponding output signals according to the input control signal.

[0032] According to the signal sent by the MCU, the D-type flip-flop will generate a corresponding level signal, such as a high level or a low level. This level signal will be used as a control signal for the P-MOS tube to determine the on or off state of the P-MOS tube.

[0033] After receiving the level signal output by the D-type trigger, the P-MOS tube unit controls its own conduction or cutoff state according to the different signals. When the P-MOS tube is turned on, it allows current to pass, making the relay closed; conversely, when the P-MOS tube is cut off, the current cannot pass, causing the relay to be disconnected.

[0034] The on or off state of the P-MOS tube ultimately controls the connection state of pin 30 and pin 87 / 87a, thereby realizing the on / off function of the relay. When the P-MOS tube is on, pin 30 is connected to pin 87 / 87a; when the P-MOS tube is off, pin 30 is disconnected from pin 87 / 87a.

[0035] Through the above steps, the MCU controls the D-flip-flop to output high and low levels by sending signals, and then realizes the relay on-off function of pin 30 and pin 87 / 87a through the control of the P-MOS tube, thereby completing the control of the relay state.

[0036] In one embodiment, the D-type flip-flop comprises a single-channel D-type flip-flop U11. The model of the single-channel D-type flip-flop U11 is but not limited to SN74LVC1G175DBVT.

[0037] In one embodiment, see Figure 2 The above-mentioned single-channel D-type trigger U11 is connected to a pull-up resistor R46, and the single-channel D-type trigger U11 is connected to a pull-down resistor R157 and a pull-down resistor R54.

[0038] In one embodiment, see Figure 2 The above-mentioned single-channel D-type trigger U11 is connected to an RC filtering circuit, which includes a current limiting debugging resistor R57, a current limiting debugging resistor R153, a ground capacitor C73, and a ground capacitor C84; one end of the ground capacitor C73 is grounded, and the other end of the ground capacitor C73 is connected between the current limiting debugging resistor R57 and the single-channel D-type trigger U11; one end of the ground capacitor C84 is grounded, and the other end of the ground capacitor C84 is connected between the current limiting debugging resistor R153 and the single-channel D-type trigger U11.

[0039] In one embodiment, see Figure 2 The above-mentioned single-channel D-type trigger U11 is also connected to a filter capacitor C66 and a bypass filter capacitor C65.

[0040] When the / CLR pin is pulled up, the Q output of the D flip-flop is controlled by the D pin and the CP pin. The specific control rules are as follows: when the level of the CP pin is at the rising edge, the level of the Q pin is equal to the level of the D pin; when the CP pin is in other states, the Q pin will maintain its original level and will not be affected by the level of the D pin. This design enables the D flip-flop to achieve the latching function. When the / CLR pin is pulled down, the Q pin is forced to be pulled low.

[0041] In this design, R46 is used as the default pull-up / CLR pin to ensure that the Q pin is always controlled by the CP pin and the D pin. In addition, positions R57 and R153 act as current limiting debugging resistors to protect the D flip-flop drive circuit. At the same time, they are combined with positions C73 and C84 to form an RC filter circuit to optimize the driving waveform of the D flip-flop 1 and 3 pins to prevent waveform jitter and ringing. In addition, positions R157 and R54 are used as pull-down resistors to pull the D pin and the CP pin down to the ground in the default state to ensure a more stable system state. Position C66 is used as a filter capacitor to make the input level more stable; C65 is used as a bypass filter capacitor to stabilize the voltage input of U11.

[0042] Through the above design, precise control of the D flip-flop is achieved, and the stability and reliability of the system are further guaranteed through the configuration of relevant resistors and capacitors.

[0043] In one embodiment, see Figure 2 The above-mentioned P-MOS tube unit includes a P-MOS tube T14 and a P-MOS tube T8, and the P-MOS tube T14 and the P-MOS tube T8 are respectively connected to a single-channel D-type trigger U11 and an electronic relay.

[0044] In one embodiment, see Figure 2 A transistor Q29 and a transistor Q26 are sequentially connected between the P-MOS transistor T14 and the single-channel D-type trigger U11.

[0045] In one embodiment, see Figure 2 A transistor Q33 and a transistor Q32 are sequentially connected between the P-MOS tube T8 and the single-channel D-type trigger U11.

[0046] In one embodiment, see Figure 2 The current limiting voltage divider resistor R111 and the current limiting voltage divider resistor R104 are connected in sequence between the P-MOS tube T14 and the transistor Q29; the current limiting voltage divider resistor R266 and the current limiting voltage divider resistor R126 are connected in sequence between the P-MOS tube T8 and the transistor Q33.

[0047] In one embodiment, see Figure 2 The above-mentioned current limiting voltage dividing resistor R111 is connected in parallel with a voltage zener diode D33; the current limiting voltage dividing resistor R266 is connected in parallel with a voltage zener diode D60.

[0048] Specifically, high-power P-MOS tubes T14 and T8 serve as the on-off circuit of the electronic relay. The two ends of the MOS tube are equivalent to the 30-pin and 87 / 87a-pin of the mechanical relay. Since there is a body diode inside the MOS tube, if there is current entering in one direction, it will flow through the body diode and the circuit cannot be disconnected. Therefore, two P-MOS tubes are used here for mirror connection, so that no matter which end the current enters from, the circuit can be disconnected by disconnecting the MOS tube, realizing the same current as the mechanical relay, which can enter from the 30-pin or the 87 / 87A pin, regardless of the direction.

[0049] The current limiting voltage divider resistors R111, R266, R104, and R126 are used to divide the external voltage to the GS end of the MOS tube when the transistors Q26 and Q33 are turned on, so that the MOS tube is turned on. At the same time, since the MOS tube is voltage-driven, the voltage divider resistor here can be selected with a larger resistance value to reduce the power dissipation of the electronic relay itself. The 15V voltage-stabilizing diodes D33 and D60 make the voltage between the G pole and the S pole of the MOS tube be clamped at 15V at most, which plays a role in protecting the MOS tube. At the same time, when the voltage-stabilizing diode is turned on and clamped, the resistors R104 and R126 can play the role of voltage division and current limiting. The circuit built by these four NPN transistors, such as Q29, Q26, Q33, and Q32, can control the on and off of the P-MOS tubes T14 and T8.

[0050] Specifically, the control principle is as follows:

[0051] When the D1_EN input is greater than the BE turn-on voltage of transistors Q29 and Q32: about 0.6V, so that their CE poles are saturated and turned on, the C and E poles of transistors Q29 and Q32 are both turned on to ground, and the B poles of transistors Q26 and Q33 are clamped at 0V, so the BE pole state of transistors Q26 and Q33 is cut off (no current passes through), and their CE state is a floating high-impedance state, so the two circuits of R111, R266, R104, and R126 are not turned on, and the voltage difference of the GS poles of the two P-MOS tubes is 0V, and the P-MOS tube will not be turned on, which is equivalent to disconnecting the relay.

[0052] When D1_EN inputs a low level, the BE of transistors Q29 and Q32 cannot be turned on, and their CE terminals are in a floating state. At this time, the external current comes in through pin 30 and pin 87 / 87A, and then the BE of Q26 and Q33 are turned on after the resistors R113, R115, R4, R267, R268, and R269 divide the voltage and limit the current, then their CE terminals are also turned on, and the C pole is pulled down to the ground. The external voltage can be divided by resistors R111, R266, R104, and R126 to the P-MOS tube, making the P-MOS tube fully turned on, which is equivalent to a closed relay.

[0053] The P-MOS tube electronic relay of this embodiment has the following advantages:

[0054] Small size: The P-MOS tube unit itself is small in size and does not require mechanical parts, so it can achieve the same or even more functions in a limited space.

[0055] Lightweight: The electronic relay of the P-MOS tube unit does not involve mechanical moving parts, so it is light in weight and suitable for application scenarios with strict weight requirements.

[0056] Long life: P-MOS tube units are less susceptible to wear and fatigue, so they have a longer working life and higher reliability.

[0057] Fast response: The P-MOS tube unit has fast turn-on and turn-off speeds and short response time, which is suitable for application scenarios that require fast switching.

[0058] Low power consumption: Compared with mechanical relays, P-MOS tube unit electronic relays consume less power, which can save energy and reduce heating problems.

[0059] With the above characteristics, electronic relays based on P-MOS tubes can provide more flexible, reliable and efficient solutions in terms of space limitations and functional requirements, and are suitable for various electronic devices and systems that require control switches.

[0060] The above-mentioned electronic relay circuit with latching function based on P-MOS tube, by setting a control unit, a D-type trigger and a P-MOS tube unit, the set P-MOS tube unit itself is small in size, does not require mechanical parts, is not easily affected by wear and fatigue, has fast turn-on and cut-off speeds, short response time, lower power consumption, can save energy and reduce heating problems, and effectively solves the limitations of traditional mechanical relays in terms of space constraints and functional requirements.

[0061] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the utility model, and these modifications or replacements should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. An electronic relay circuit with latching function based on a P-MOS tube, characterized in that: include: A control unit, a D-type trigger and a P-MOS tube unit, wherein the P-MOS tube unit is connected to an electronic relay; The control unit is used to output a control signal; The D-type trigger is used to output a level signal according to the control signal; the P-MOS tube unit is used to be turned on or off according to the level signal to realize the closing or opening of the electronic relay.

2. The electronic relay circuit with latching function based on P-MOS tube according to claim 1, characterized in that: The D-type flip-flop includes a single-channel D-type flip-flop U11.

3. The electronic relay circuit with latching function based on P-MOS tube according to claim 2, characterized in that: The single-channel D-type flip-flop U11 is connected to a pull-up resistor R46 , and the single-channel D-type flip-flop U11 is connected to a pull-down resistor R157 and a pull-down resistor R54 .

4. The electronic relay circuit with latching function based on P-MOS tube according to claim 3, characterized in that: The single-channel D-type trigger U11 is connected to an RC filtering circuit, which includes a current limiting debugging resistor R57, a current limiting debugging resistor R153, a ground capacitor C73, and a ground capacitor C84; one end of the ground capacitor C73 is grounded, and the other end of the ground capacitor C73 is connected between the current limiting debugging resistor R57 and the single-channel D-type trigger U11; one end of the ground capacitor C84 is grounded, and the other end of the ground capacitor C84 is connected between the current limiting debugging resistor R153 and the single-channel D-type trigger U11.

5. The electronic relay circuit with latching function based on P-MOS tube according to claim 4, characterized in that: The single-channel D-type trigger U11 is also connected to a filter capacitor C66 and a bypass filter capacitor C65.

6. The electronic relay circuit with latching function based on P-MOS tube according to claim 2, characterized in that: The P-MOS tube unit includes a P-MOS tube T14 and a P-MOS tube T8. The P-MOS tube T14 and the P-MOS tube T8 are connected to the single-channel D-type trigger U11 and the electronic relay respectively.

7. The electronic relay circuit with latching function based on P-MOS tube according to claim 6, characterized in that: A transistor Q29 and a transistor Q26 are sequentially connected between the P-MOS transistor T14 and the single-channel D-type trigger U11 .

8. The electronic relay circuit with latching function based on P-MOS tube according to claim 7, characterized in that: A transistor Q33 and a transistor Q32 are sequentially connected between the P-MOS transistor T8 and the single-channel D-type trigger U11 .

9. The electronic relay circuit with latching function based on P-MOS tube according to claim 8, characterized in that: A current limiting voltage divider resistor R111 and a current limiting voltage divider resistor R104 are connected in sequence between the P-MOS transistor T14 and the transistor Q29 ; a current limiting voltage divider resistor R266 and a current limiting voltage divider resistor R126 are connected in sequence between the P-MOS transistor T8 and the transistor Q33 .

10. The electronic relay circuit with latching function based on P-MOS tube according to claim 9, characterized in that: The current limiting voltage dividing resistor R111 is connected in parallel with a voltage zener diode D33; the current limiting voltage dividing resistor R266 is connected in parallel with a voltage zener diode D60.

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