Relay driving circuit

Abstract

The utility model discloses a relay driving circuit which comprises a control driving module, a boost driving module and a power-on transmission module. A control signal is accessed to the control end of the control driving module, the first end of the control driving module is grounded, and the control driving module switches on or switches off the connection between the first end and the second end according to the control signal; the control end of the boost driving module is connected with the second end of the control driving module, the output end of the boost driving module is connected with the first end of the relay coil, and the boost driving module is used for boosting and transmitting voltage to the first end of the relay coil after the control driving module is conducted; the power-on transmission module is connected between the second end of the relay coil and the second end of the control driving module, and after the control driving module is switched on, the power-on transmission module, the relay coil, the control driving module and the boost driving module form a loop so that the relay coil can be powered on. According to the relay driving circuit, the driving speed is improved through low impedance and high driving voltage.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit control, in particular to a relay driving circuit. Background Art

[0002] As an electrical switching device, relays are widely used in various electrical control systems to switch working states. In some cases, there are strict requirements on the opening time of the relay, and a driving circuit is needed to quickly open the relay.

[0003] At present, the relay driving circuit generally includes an energy storage capacitor, which transfers the stored energy to the relay coil to increase the driving voltage of the relay coil, so that the relay can be turned on quickly. However, the current limiting resistor in the driving circuit is large, which will prevent the driving voltage of the relay coil from increasing, thereby reducing the relay conduction speed. Utility Model Content

[0004] The utility model provides a relay driving circuit to solve the problem of slow driving speed of the relay driving circuit in the prior art.

[0005] According to one aspect of the utility model, there is provided a relay drive circuit, comprising a control drive module, a boost drive module and a power-on transmission module;

[0006] The control driving module comprises a control end, a first end and a second end, the control end of the control driving module is connected to a control signal, the first end of the control driving module is grounded, and the control driving module is used to turn on or off the connection between the first end and the second end according to the control signal;

[0007] The control end of the boost driving module is connected to the second end of the control driving module, the output end of the boost driving module is connected to the first end of the relay coil, and the boost driving module is used to boost and transmit the voltage to the first end of the relay coil after the control driving module is turned on;

[0008] The power-on transmission module is connected between the second end of the relay coil and the second end of the control drive module. After the control drive module is turned on, the power-on transmission module forms a loop with the relay coil, the control drive module and the boost drive module to energize the relay coil.

[0009] Optionally, the relay drive circuit also includes an adjustment module, which connects the power-on transmission module and the boost drive module, and is used to adjust the conduction state of the power-on transmission module and the conduction state of the boost drive module, wherein the adjustment module includes a first capacitor.

[0010] Optionally, the boost drive module includes a power supply unit, a drive unit and an energy storage unit, the control end of the drive unit is connected to the control end of the boost drive module, the first end of the drive unit is connected to the power-on transmission module, the second end of the drive unit is connected to the energy storage unit, the energy storage unit is connected to the power supply unit and the output end of the boost drive module, the power supply unit is used to supply power, and the drive unit is used to drive the energy storage unit to boost voltage.

[0011] Optionally, the power supply unit includes a first power supply and a first diode, a first end of the first diode is connected to the first power supply, and a second end of the first diode is connected to an output end of the boost driving module.

[0012] Optionally, the driving unit includes a first transistor and a first resistor, the first end of the first resistor is connected to the control end of the driving unit, the second end of the first resistor is connected to the control end of the first transistor, the first end of the first transistor is connected to the first end of the driving unit, and the second end of the first transistor is connected to the second end of the driving unit.

[0013] Optionally, the energy storage unit includes a second capacitor and a second resistor, the first end of the second capacitor is connected to the output end of the boost drive module, the second end of the second capacitor is connected to the second end of the drive unit and the first end of the second resistor, and the second end of the second resistor is grounded.

[0014] Optionally, the power-on transmission module includes a second transistor, a third resistor and a second diode, the first end of the second transistor is connected to the second end of the relay coil, the control end of the second transistor is connected to the first end of the third resistor and the first end of the second diode, and the second end of the second transistor, the second end of the third resistor and the second end of the second diode are all connected to the second end of the control drive module.

[0015] Optionally, the control driving module includes a third transistor, a fourth resistor and a fifth resistor, the first end of the fourth resistor is connected to the control end of the control driving module, the second end of the fourth resistor is connected to the first end of the fifth resistor and the control end of the third transistor, the second end of the fifth resistor is connected to the first end of the third transistor, and the second end of the third transistor is connected to the second end of the control driving module.

[0016] Optionally, the relay drive circuit also includes a current limiting module, a first end of the current limiting module is connected to the second end of the relay coil, a second end of the current limiting module is connected to the second end of the control drive module, and the current limiting module is used to limit the current of the relay power supply circuit, wherein the current limiting module includes a current limiting resistor.

[0017] Optionally, the relay drive circuit further includes a freewheeling diode, a first end of the freewheeling diode being connected to the second end of the relay coil, a second end of the freewheeling diode being connected to the first end of the relay coil, and the freewheeling diode being used to form a power consumption path when the relay coil loses power.

[0018] The technical solution of the embodiment of the utility model provides a relay drive circuit, including a control drive module, a boost drive module and a power-on transmission module. The control end of the control drive module is connected to the control signal, the first end of the control drive module is grounded, the control drive module switches on or off the connection between the first end and the second end according to the control signal, the control end of the boost drive module is connected to the second end of the control drive module, the output end of the boost drive module is connected to the first end of the relay coil, the boost drive module is used to boost and transmit the voltage to the first end of the relay coil after the control drive module is turned on, the power-on transmission module is connected between the second end of the relay coil and the second end of the control drive module, and after the control drive module is turned on, the power-on transmission module forms a loop with the relay coil, the control drive module and the boost drive module to energize the relay coil. The boost drive module in the relay drive circuit provided by the utility model provides a higher driving voltage for the relay coil, and the conduction impedance in the loop formed by the power-on transmission module, the relay coil, the control drive module and the boost drive module is low, which improves the speed of relay opening and solves the problem of slow driving speed of the relay drive circuit in the prior art.

[0019] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the utility model, nor is it intended to limit the scope of the utility model. Other features of the utility model will become easy to understand through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 It is a circuit diagram of a relay drive circuit provided by the related technology;

[0022] Figure 2 It is a structural schematic diagram of a relay drive circuit provided by an embodiment of the utility model;

[0023] Figure 3 It is a circuit diagram of a relay drive circuit provided by an embodiment of the utility model;

[0024] Figure 4 It is a relay opening equivalent circuit diagram provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the utility model described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0027] As an electrical switching device, relays are widely used in various electrical control systems to switch working states. In some cases, there are strict requirements on the opening time of the relay, and a driving circuit is needed to quickly open and close the relay. Figure 1 It is a circuit diagram of a relay drive circuit provided by the related technology, such as Figure 1As shown, when the input signal RLYCTR is high, capacitor C01 is charged, transistor Q01 is turned on, the potential of terminal D is pulled from +12V to 0V, transistor Q02 is turned on, the negative electrode of capacitor C02 is raised, and the potential of pin 1 of relay K0 is raised, so that relay K0 is turned on faster. After relay K0 is turned on, capacitor C02 is discharged, diode D01 is turned off, and capacitor C02 is discharged through the coil between pins 1 and 2 of relay K and the path of transistor Q01. After capacitor C02 is fully discharged, the 12V power supply supplies power to relay K0 through resistor R01 and diode D01. When switching off the relay: the input signal RLYCTR is low, capacitor C01 is discharged, transistor Q01 is turned off, the potential of terminal D rises from 0V, the current of the coil of relay K0 flows into capacitor C03, and the 12V power supply charges capacitor C03, so that the potential of terminal D rises rapidly, which will quickly reduce the freewheeling current of the coil of relay K0 to 0, completing the accelerated shutdown of the relay. The relay driving circuit also includes capacitor C04, diode D02, voltage stabilizing diode D03, resistor R02 and resistor R03. However, the current limiting resistor R01 in the driving circuit will prevent the driving voltage of the relay coil from increasing, reducing the relay conduction speed.

[0028] In order to solve the above problems, the embodiment of the utility model provides a relay driving circuit. Figure 2 Schematic diagram of a relay drive circuit provided by an embodiment of the utility model. Figure 2 As shown, the relay drive circuit includes a control drive module 110, a boost drive module 120 and a power-on transmission module 130; the control drive module 110 includes a control terminal a, a first terminal b and a second terminal c, the control terminal a of the control drive module 110 is connected to a control signal, the first terminal b of the control drive module 110 is grounded, and the control drive module 110 is used to turn on or off the connection between the first terminal b and the second terminal c according to the control signal; the control terminal d of the boost drive module 120 is connected to the second terminal c of the control drive module 110, the output terminal e of the boost drive module 120 is connected to the first terminal of the coil of the relay K, and the boost drive module 120 is used to boost and transmit the voltage to the first terminal of the coil of the relay K after the control drive module 110 is turned on; the power-on transmission module 130 is connected between the second terminal of the coil of the relay K and the second terminal of the control drive module 110, and after the control drive module 110 is turned on, the power-on transmission module 130 forms a loop with the coil of the relay K, the control drive module 110 and the boost drive module 120 to energize the coil of the relay K.

[0029] In this embodiment, the control drive module 110 is a module that controls the relay drive circuit to be turned on or off according to a control signal, wherein the control signal can be represented by a level signal. The boost drive module 120 is a module that provides a driving voltage for the relay coil, and the boost drive module 120 increases the driving voltage of the relay coil by boosting. The power-on transmission module 130 is a module that transmits the current output by the relay coil when the relay is turned on according to the driving voltage. The power-on transmission module 130 is turned on after the control drive module 110 is turned on, and forms a loop for relay coil current transmission with the coil of the relay K, the control drive module 110 and the boost drive module 120, wherein the control drive module 110 is turned on means that the first end b and the second end c are turned on.

[0030] Exemplarily, when the relay is turned on, the control signal connected to the control terminal a of the control drive module 110 is at a high level, the control drive module 110 turns on the connection between the first terminal b and the second terminal c, the boost drive module 120 boosts the voltage and transmits the boosted voltage to the first end of the coil of the relay K, the power-on transmission module 130 forms a loop with the coil of the relay K, the control drive module 110 and the boost drive module 120, the coil of the relay K is quickly energized according to the voltage output by the boost drive module 120, and the relay is quickly turned on.

[0031] The technical solution of this embodiment provides a relay drive circuit, including a control drive module, a boost drive module and a power-on transmission module. The control end of the control drive module is connected to a control signal, the first end of the control drive module is grounded, the control drive module switches on or off the connection between the first end and the second end according to the control signal, the control end of the boost drive module is connected to the second end of the control drive module, the output end of the boost drive module is connected to the first end of the relay coil, the boost drive module is used to boost and transmit the voltage to the first end of the relay coil after the control drive module is turned on, the power-on transmission module is connected between the second end of the relay coil and the second end of the control drive module, and after the control drive module is turned on, the power-on transmission module forms a loop with the relay coil, the control drive module and the boost drive module to energize the relay coil. The boost drive module in the relay drive circuit provided in this embodiment provides a higher driving voltage for the relay coil, and the conduction impedance in the loop formed by the power-on transmission module, the relay coil, the control drive module and the boost drive module is low, which improves the speed of relay conduction and solves the problem of slow driving speed of the relay drive circuit in the prior art.

[0032] Figure 3 is a circuit diagram of a relay drive circuit provided by an embodiment of the utility model, such as Figure 3As shown, the boost drive module 120 includes a power supply unit, a drive unit and an energy storage unit. The control end of the drive unit is connected to the control end d of the boost drive module 120, the first end of the drive unit is connected to the power transmission module 130, the second end of the drive unit is connected to the energy storage unit, the energy storage unit is connected to the power supply unit and the output end e of the boost drive module 120, the power supply unit is used to supply power to the energy storage unit, and the drive unit is used to drive the energy storage unit to boost.

[0033] In this embodiment, the power supply unit is a unit for supplying power to the relay drive circuit, and the power supply unit includes a power supply. The drive unit is a unit that drives the energy storage unit to work, and the drive unit is turned on or off according to the input signal, for example, the drive unit includes a switch element, etc. The energy storage unit is a unit for storing energy and boosting, and the energy storage unit includes an energy storage element, etc. On the basis of the above embodiment, when the relay is turned on, the control drive module 110 is turned on according to the high-level control signal connected to the control terminal a, the drive unit in the boost drive module 120 is turned on, the energy storage unit is boosted to a preset voltage according to the voltage output by the power supply unit, and the boosted voltage is transmitted to the first end of the coil of the relay K, the power-on transmission module 130 forms a loop with the coil of the relay K, the control drive module 110 and the boost drive module 120, the coil of the relay K is quickly energized according to the voltage output by the energy storage unit, and the relay is quickly turned on.

[0034] Specifically, the power supply unit includes a first power supply V1 and a first diode D1, wherein the first end of the first diode D1 is connected to the first power supply V1, and the second end of the first diode D1 is connected to the output end e of the boost driving module 120. The driving unit includes a first transistor Q1 and a first resistor R1, wherein the first end of the first resistor R1 is connected to the control end of the driving unit, the second end of the first resistor R1 is connected to the control end of the first transistor Q1, the first end of the first transistor Q1 is connected to the first end of the driving unit, and the second end of the first transistor Q1 is connected to the second end of the driving unit. The energy storage unit includes a second capacitor C2 and a second resistor R2, wherein the first end of the second capacitor C2 is connected to the output end e of the boost driving module 120, the second end of the second capacitor C2 is connected to the driving unit and the first end of the second resistor R2, and the second end of the second resistor R2 is grounded.

[0035] In this embodiment, the first power supply V1 is a 12V power supply. When the relay is not turned on (equivalent to the control signal connected to the control terminal a of the control driving module 110 being at a low level), the potential of the first terminal A of the driving unit is 12V, the potential of the second terminal B of the driving unit is 0V, and the potential of the output terminal e of the boost driving module 120 is 12V, that is, the voltage difference across the second capacitor C2 is 12V, and the potential of the control terminal d of the boost driving module 120 is 12V. With reference to the above embodiment, when the relay is turned on, the control drive module 110 is turned on according to the high-level control signal connected to the control terminal a, the first transistor Q1 is turned on, and the potential of the second terminal B of the drive unit is raised to 12V. Since the stored charge of the second capacitor C2 cannot mutate, the voltage difference across the second capacitor C2 remains unchanged, and the potential of the output terminal e of the boost drive module 120 is raised from 12V to 24V, that is, the driving voltage provided by the boost drive module 120 to the relay is 24V, and the power-on transmission module 130 forms a loop with the coil of the relay K, the control drive module 110, the second resistor R2 and the second capacitor C2, and the relay K is quickly turned on according to the 24V voltage output by the energy storage unit.

[0036] Continue to refer Figure 3 The power-on transmission module 130 includes a second transistor Q2, a third resistor R3 and a second diode D2, a first end of the second transistor Q2 is connected to the second end of the relay coil, a control end of the second transistor Q2 is connected to the first end of the third resistor R3 and the first end of the second diode D2, and a second end of the second transistor Q2, a second end of the third resistor R3 and a second end of the second diode D2 are connected to a second end c of the control driving module 110.

[0037] In this embodiment, the conduction impedance of the second transistor Q2 is relatively low. Referring to the above embodiment, when the relay is turned on, the control driving module 110 is turned on according to the high-level control signal connected to the control terminal a, the first transistor Q1 is turned on, the second transistor Q2 is turned on, the potential of the second terminal B of the driving unit is raised to 12V, the potential of the output terminal e of the boost driving module 120 is raised from 12V to 24V, and the driving voltage provided by the boost driving module 120 to the relay is 24V. The second transistor Q2 forms a loop with the coil of the relay K, the control driving module 110, the second resistor R2 and the second capacitor C2, and the relay K is quickly turned on according to the 24V voltage output by the energy storage unit. Since the conduction impedance of the second transistor Q2 is relatively low, the conduction speed of the relay can be effectively improved.

[0038] Continue to refer Figure 3The control driving module 110 includes a third transistor Q3, a fourth resistor R4 and a fifth resistor R5, a first end of the fourth resistor R4 is connected to the control end a of the control driving module 110, a second end of the fourth resistor R4 is connected to the first end of the fifth resistor R5 and the control end of the third transistor Q3, a second end of the fifth resistor R5 is connected to the first end of the third transistor Q3, and a second end of the third transistor Q3 is connected to the second end c of the control driving module 110.

[0039] On the basis of the above embodiment, when the control signal connected to the control terminal a of the control driving module 110 is at a high level, the third transistor Q3 is turned on, and the potential of the second terminal of the third transistor Q3 (the control terminal d of the boost driving module 120) is pulled from 12V to 0V. Since the third resistor R3 has a large resistance and the second diode D2 has unidirectional conductivity, the potential of the first terminal A of the driving unit (the control terminal of the second transistor Q2) will slowly drop from 12V, that is, the potential difference between the control terminal of the second transistor Q2 and the second terminal of the second transistor Q2 will cause the second transistor Q2 to be turned on. At this time, the second terminal of the relay coil is grounded through the second transistor Q2 and the third transistor Q3, and the first terminal of the relay coil is connected to the first power supply. Since the conduction impedance of the second transistor Q2 is extremely low, a low impedance circuit is provided for charging the relay coil. At the same time, since the first transistor Q1 is turned on, the potential of the second terminal B (the second terminal of the first transistor Q1) of the driving unit is pulled up, which is equal to the potential of the first terminal A (the first terminal of the first transistor Q1) of the driving unit, 12V. Due to the unidirectional conductivity of the first diode D1, the charge stored in the second capacitor C2 cannot change suddenly, and the voltage drop at both ends remains unchanged. The potential of the output terminal e of the boost driving module 120 is raised from 12V to 24V, which increases the voltage drop on both sides of the relay and improves the driving voltage of the relay. At this time, the first power supply V1 supplies power to the relay coil through the first diode D1, and the power supply circuit includes the first diode D1, the relay coil, the second transistor Q2 and the third transistor Q3. At the same time, the second capacitor C2 also supplies power to the relay coil, and the power supply circuit includes the second capacitor C2, the relay coil, the second transistor Q2 and the third transistor Q3. Since the potential at the output terminal point e of the boost drive module 120 is raised and the on-resistance of the second transistor Q2 is low, the conduction process of the relay can be regarded as the process of the coil current increasing to the conduction threshold. The high drive voltage and low impedance circuit can realize the relay current increasing at a faster rate and accelerate the conduction of the relay.

[0040] Based on the above embodiments, Figure 3As shown, the relay driving circuit also includes a regulating module 220 and a current limiting module 210, the regulating module 220 is connected to the power-on transmission module 130 and the boost driving module 120, the regulating module 220 is used to adjust the conduction state of the power-on transmission module 130, and the conduction state of the boost driving module 120, wherein the regulating module 220 includes a first capacitor C1. The current limiting module 210 is connected to the second end of the relay coil and the second end c of the control driving module 110, and the current limiting module 210 is used to limit the current of the relay power supply circuit, wherein the current limiting module 210 includes a current limiting resistor Rx.

[0041] In this embodiment, the regulating module 220 can regulate the power-on transmission module 130 and the boost driving module 120. The regulating module 220 includes a first capacitor C1. For example, the power-on transmission module 130 and the boost driving module 120 can be turned off by changing the parameters of the first capacitor C1. The current limiting module 210 is a module that limits the current of the relay power supply circuit after the relay is powered on and stabilized.

[0042] Exemplarily, as the relay coil is charged, the first capacitor C1 is discharged through the third resistor R3 and the first resistor R1. The first capacitor C1 is a large-capacity capacitor, which can ensure that the potential of the first terminal A of the driving unit slowly decreases, so that the second transistor Q2 is turned on and the first transistor Q1 is turned on. By adjusting the capacitance parameters of the first capacitor C1, the second transistor Q2 and the first transistor Q1 can be turned off after the relay is attracted, and the first capacitor C1 is discharged until the potential of point A is reduced to a voltage less than the turn-on voltage of the second transistor Q2 and the first transistor Q1, and the second transistor Q2 and the first transistor Q1 are turned off. At this time, the relay driving circuit is in a stable state, the first terminal A of the driving unit, the control terminal d of the boost driving module 120, and the second terminal B of the driving unit are low level, the output terminal e of the boost driving module 120 is high level, the third transistor Q3 remains turned on, the first transistor Q1 and the second transistor Q2 remain turned off, and the high level output by the output terminal e of the boost driving module 120 supplies power to the relay coil, and the current output by the second terminal of the relay coil is transmitted to the ground through the current limiting resistor Rx and the third transistor Q3. During the relay closing period, the first transistor Q1 and the second transistor Q2 do not generate loss, thereby reducing the energy loss of the circuit.

[0043] In this embodiment, the relay drive circuit also includes a freewheeling diode Dx, a first end of the freewheeling diode Dx is connected to the second end of the relay coil, and a second end of the freewheeling diode Dx is connected to the first end of the relay coil. The freewheeling diode Dx is used to form a power consumption path when the relay coil loses power.

[0044] Exemplarily, the shutdown process of the relay includes: when the circuit is stable, the control signal connected to the control terminal a of the control driving module 110 is at a low level, the third transistor Q3 is turned off, the first power supply V1 charges the first capacitor C1 through the relay coil, the current limiting resistor Rx and the second diode D2, the potential of the control terminal d of the boost driving module 120 and the first terminal A of the driving unit begin to gradually rise, the current begins to gradually decrease, the relay coil will prevent the current from decreasing, and generate an electromotive force opposite to the current. Due to the unidirectional conductivity of the freewheeling diode Dx, the freewheeling diode Dx is turned on to generate a freewheeling loop. At the same time, part of the current of the relay coil flows to the first capacitor C1, since the second transistor Q2 is turned on and the first transistor Q1 is turned off, the potentials of the first terminal A of the driving unit, the control terminal d of the boost driving module 120 and the output terminal e of the boost driving module 120 are equal, which is equal to the voltage of the first power supply V1 minus the conduction voltage drop of the first diode D1. The current loops of the relay coil being turned off are: the freewheeling loop formed by the relay coil and the freewheeling diode Dx, and the loop formed by the relay coil, the current limiting resistor Rx, the second diode D2 and the first capacitor C1. The second diode D2 has a low conduction impedance, so that the first capacitor C1 is quickly charged, and the relay is discharged through the two loops, which can accelerate the shutdown of the relay.

[0045] Exemplarily, the relay conduction process can be regarded as a charging process of the relay coil. When the driving current reaches the relay conduction threshold, the relay is energized and turned on. Figure 4 : is a relay opening equivalent circuit diagram provided by the embodiment of the utility model, such as Figure 4 As shown, assuming that the initial current and voltage of the relay coil are both 0, ignoring the conduction voltage drop of the first diode D1 and the equivalent resistance of the second capacitor C2, the driving current starts to increase from t=0, then the relationship between the relay coil current and time is:

[0046]

[0047] R o =R relay +R on

[0048] R on =R Q2 +R Q3

[0049] Where: V o is the driving voltage of the relay, R o is the total resistance of the relay drive circuit, L is the equivalent inductance of the relay coil; R relay is the equivalent impedance of the relay coil; R on is the equivalent driving resistance; R equal is the equivalent resistance of capacitor C2 discharge, V power is the power supply voltage, RQ2 is the on-resistance of Q2, R Q3 is the on-resistance of Q3.

[0050] It can be seen from the formula that i(t) and V o Positive correlation, i(t) and R o Negative correlation, and time constant τ = R o / L and R o The relay driving circuit provided in this embodiment accelerates the conduction by increasing V o , reduce R o , shortening the time t that the driving current reaches the relay conduction threshold. Figure 1 As shown, R on =R 限流电阻 +R Q01 , R 限流电阻 The circuit R of this embodiment is of Ω level. Q3 The on-resistance is in the mΩ level, that is Figure 4 Medium R o Less than Figure 1 Medium R o Taking the relay (832HA-1C-FC 12Vdc 40A / 277Vac 5PIN) as an example, the existing R on =33Ω+155Ω=188Ω, R on =155Ω, the conduction speed will be reduced to less than 0.82 times of the existing one ( The time constant is reduced by 0.82 times, and the time constant is also reduced by 0.82 times, which is related to the relay action current threshold and the coil inductance). In addition, when the relay is turned on and working stably, only the third transistor Q3 remains turned on, which generates less loss than the prior art.

[0051] In this embodiment, the relay drive circuit provides a higher driving voltage for the relay coil through the boost drive module. The impedance in the loop formed by the power-on transmission module, the relay coil, the control drive module and the boost drive module is low. By reducing the on-resistance and increasing the drive voltage, the relay coil can quickly store energy, so that the relay can be quickly turned on. At the same time, the relay drive circuit has the advantages of low operating loss and high reliability.

[0052] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0053] The above specific implementations do not constitute a limitation on the protection scope of the present utility model. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A relay drive circuit, characterized in that: It includes a control drive module, a boost drive module and a power-on transmission module; The control driving module comprises a control end, a first end and a second end, the control end of the control driving module is connected to a control signal, the first end of the control driving module is grounded, and the control driving module is used to turn on or off the connection between the first end and the second end according to the control signal; The control end of the boost driving module is connected to the second end of the control driving module, the output end of the boost driving module is connected to the first end of the relay coil, and the boost driving module is used to boost and transmit the voltage to the first end of the relay coil after the control driving module is turned on; The power-on transmission module is connected between the second end of the relay coil and the second end of the control drive module. After the control drive module is turned on, the power-on transmission module forms a loop with the relay coil, the control drive module and the boost drive module to energize the relay coil.

2. The relay drive circuit according to claim 1, characterized in that: It also includes a regulating module, which is connected to the power-on transmission module and the boost driving module, and is used to adjust the conduction state of the power-on transmission module and the conduction state of the boost driving module, wherein the regulating module includes a first capacitor.

3. The relay drive circuit according to claim 1, characterized in that: The boost drive module includes a power supply unit, a drive unit and an energy storage unit. The control end of the drive unit is connected to the control end of the boost drive module, the first end of the drive unit is connected to the power-on transmission module, the second end of the drive unit is connected to the energy storage unit, the energy storage unit is connected to the power supply unit and the output end of the boost drive module, the power supply unit is used to supply power, and the drive unit is used to drive the energy storage unit to boost.

4. The relay drive circuit according to claim 3, characterized in that: The power supply unit includes a first power supply and a first diode, wherein a first end of the first diode is connected to the first power supply, and a second end of the first diode is connected to an output end of the boost driving module.

5. The relay drive circuit according to claim 3, characterized in that: The driving unit includes a first transistor and a first resistor, wherein a first end of the first resistor is connected to a control end of the driving unit, a second end of the first resistor is connected to a control end of the first transistor, a first end of the first transistor is connected to a first end of the driving unit, and a second end of the first transistor is connected to a second end of the driving unit.

6. The relay drive circuit according to claim 3, characterized in that: The energy storage unit includes a second capacitor and a second resistor, a first end of the second capacitor is connected to the output end of the boost driving module, a second end of the second capacitor is connected to the second end of the driving unit and the first end of the second resistor, and a second end of the second resistor is grounded.

7. The relay drive circuit according to claim 1, characterized in that: The power-on transmission module includes a second transistor, a third resistor and a second diode, the first end of the second transistor is connected to the second end of the relay coil, the control end of the second transistor is connected to the first end of the third resistor and the first end of the second diode, and the second end of the second transistor, the second end of the third resistor and the second end of the second diode are all connected to the second end of the control drive module.

8. The relay drive circuit according to claim 1, characterized in that: The control driving module includes a third transistor, a fourth resistor and a fifth resistor, wherein the first end of the fourth resistor is connected to the control end of the control driving module, the second end of the fourth resistor is connected to the first end of the fifth resistor and the control end of the third transistor, the second end of the fifth resistor is connected to the first end of the third transistor, and the second end of the third transistor is connected to the second end of the control driving module.

9. The relay driving circuit according to claim 1, characterized in that: It also includes a current limiting module, a first end of the current limiting module is connected to the second end of the relay coil, and a second end of the current limiting module is connected to the second end of the control drive module. The current limiting module is used to limit the current of the relay power supply circuit, wherein the current limiting module includes a current limiting resistor.

10. The relay driving circuit according to claim 1, characterized in that: It also includes a freewheeling diode, a first end of which is connected to the second end of the relay coil, and a second end of which is connected to the first end of the relay coil. The freewheeling diode is used to form a power consumption path when the relay coil loses power.

Images