CN117792367A - 28V power on-off control circuit - Google Patents

Abstract

The invention relates to the field of circuit on-off control, in particular to a 28V power on-off control circuit. The switch control module comprises an optical coupler, a PMOS tube, a current limiting resistor, a first voltage limiting resistor and a second voltage limiting resistor, wherein the optical coupler is electrically connected with the PMOS tube, the PMOS tube is electrically connected with the positive electrode of the power supply, the current limiting resistor is connected with the PMOS tube in parallel, the first voltage limiting resistor is electrically connected with the optical coupler, the second voltage limiting resistor is electrically connected with the optical coupler, the discharge module comprises a polarity capacitor, the positive electrode of the polarity capacitor is electrically connected with the positive electrode of the power supply, and the negative electrode of the polarity capacitor is electrically connected with the common mode inductor. Thus, the problem of on-off control of a 28V power supply is solved.

Description

28V power on-off control circuit

Technical Field

The invention relates to the field of circuit on-off control, in particular to a 28V power on-off control circuit.

Background

The existing scheme only has the defects that a 28V power on-off control circuit is not designed for a conventional filter circuit, a 28V long-time electrified design scheme or a more complex 28V power on-off control circuit is adopted, and the existing scheme can lead to long-time working states of a motor driver and a motor due to electric mechanism interference, misoperation and the like, so that the loss of the motor driver and the motor cannot be effectively reduced, and the long-time working and the service life extension of the motor driver and the motor are not facilitated.

Disclosure of Invention

In order to solve the problem of 28V power on-off control, the invention provides a 28V power on-off control circuit, which comprises:

a switch control module and a discharge module;

the switch control module comprises an optical coupler, a PMOS tube, a current limiting resistor, a first voltage limiting resistor and a second voltage limiting resistor;

the optical coupler is electrically connected with the PMOS tube;

the PMOS tube is electrically connected with the positive electrode of the power supply;

the current limiting resistor is connected with the PMOS tube in parallel;

the first voltage limiting resistor is electrically connected with the optical coupler;

the second voltage limiting resistor is electrically connected with the optical coupler;

the discharging module comprises a polar capacitor, wherein the positive electrode of the polar capacitor is electrically connected with the positive electrode of the power supply, and the negative electrode of the polar capacitor is electrically connected with the common mode inductor.

In the above description, the PMOS transistor refers to an N-type substrate and a P-channel, and the MOS transistor is classified into an N-channel and a P-channel, where the P-channel silicon MOS transistor has two p+ regions on the N-type substrate, which are called a source and a drain, respectively, and the two electrodes are not conducted, and when a sufficient positive voltage is applied to the source (the gate is grounded), the surface of the N-type silicon under the gate presents a P-type inversion layer, and becomes a channel connecting the source and the drain. Changing the gate voltage can change the hole density in the channel, thereby changing the resistance of the channel. Such a MOS field effect transistor is called a P-channel enhancement type field effect transistor. If the P-type inversion layer channel exists on the surface of the N-type silicon substrate without applying a gate voltage, the resistance of the channel can be increased or decreased by applying a proper bias voltage. Such MOS field effect transistors are referred to as P-channel depletion type field effect transistors, collectively referred to as PMOS transistors.

In some embodiments, the optocoupler first pin is electrically connected to the first voltage limiting resistor;

the second pin of the optical coupler is grounded;

the third pin of the optical coupler is electrically connected with the second voltage limiting resistor;

and the fourth pin of the optical coupler is electrically connected with the grid electrode of the PMOS tube.

In some embodiments, the source electrode of the PMOS transistor is electrically connected to the positive electrode of the polar capacitor and the positive electrode of the power supply;

the grid electrode of the PMOS tube is electrically connected with the third pin of the optical coupler;

the drain electrode of the PMOS tube is connected with an output signal.

In some embodiments, the 28V power on-off control circuit further comprises a first filtering module and a second filtering module.

In some embodiments, the first filtering module is a circuit comprising a common mode inductor, a TVS diode;

the first pin of the common mode inductor is connected with the positive electrode of the power supply;

the second pin of the common mode inductor is grounded;

the third pin of the common mode inductor is electrically connected with the cathode of the TVS diode;

the fourth pin of the common mode inductor is electrically connected with the anode of the TVS diode;

the positive electrode of the TVS diode is electrically connected with the third pin of the common mode inductor, and the negative electrode of the TVS diode is electrically connected with the positive electrode of the power supply.

In the above description, the TVS diode is collectively referred to as a transient voltage suppression diode (Transient voltage suppression diode), which is an electronic component for protection that can protect electrical equipment from voltage spikes introduced by wires. The TVS diode will be connected in parallel with the circuit to be protected. When the voltage exceeds the breakdown level, the excessive current is directly shunted. The TVS diode is a clamp that suppresses excessive voltages beyond its breakdown voltage. When the overvoltage disappears, the TVS diode automatically returns, and the absorbed energy is much larger than that of a similar rated crowbar circuit.

In some embodiments, the second filtering module is a filter comprising a differential mode inductance, a first porcelain capacitor, and a second porcelain capacitor;

one end of the first ceramic capacitor is electrically connected with the differential mode inductor, and the other end of the first ceramic capacitor is electrically connected with a third pin of the common mode inductor;

and one end of the second ceramic capacitor is electrically connected with the other end of the differential mode inductor, and the other end of the second ceramic capacitor is electrically connected with the third pin of the common mode inductor.

In some embodiments, one end of the current limiting resistor is electrically connected with the source electrode of the PMOS transistor and the differential mode inductor, and the other end of the current limiting resistor is electrically connected with the fourth pin of the optocoupler and the gate electrode of the PMOS transistor;

one end of the first voltage limiting resistor is electrically connected with the first pin of the optical coupler, and the other end of the first voltage limiting resistor is connected with an input signal;

one end of the second voltage limiting resistor is electrically connected with the third pin of the optical coupler, and the other end of the second voltage limiting resistor is grounded.

In order to solve the problem of on-off control of a 28V power supply, the invention has the following advantages:

1, the control problem of 28V power on-off is solved by using less device consumption and a simpler circuit form, and the EMC filtering problem is also compatible.

The 2 filter circuit not only can restrain the voltage and current overshoot generated by the motor and reduce the electromagnetic interference of a 28V power line, but also can work normally in an instantaneous interruption state, thereby avoiding the uncontrolled electric mechanism caused by the instantaneous interruption of the power supply.

And 3, by controlling the 28V power on-off control circuit, the standby state motor of the electric mechanism can be ensured to be in a non-working state, and the loss of the motor driver and the motor is reduced, so that the service lives of the motor driver and the motor are ensured to meet the whole life cycle requirement of the electric mechanism.

Drawings

FIG. 1 shows a 28V power EMC filtering and on-off control electrical schematic diagram;

Detailed Description

The disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those of ordinary skill in the art to better understand and thus practice the present disclosure, and are not meant to imply any limitation on the scope of the present disclosure.

As used herein, the term "comprising" and variants thereof are to be interpreted as meaning "including but not limited to" open-ended terms. The term "based on" is to be interpreted as "based at least in part on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment. The term "another embodiment" is to be interpreted as "at least one other embodiment". The terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "transverse", "longitudinal", etc. refer to an orientation or positional relationship based on that shown in the drawings. These terms are used primarily to better describe the present application and its embodiments and are not intended to limit the indicated device, element or component to a particular orientation or to be constructed and operated in a particular orientation. Also, some of the terms described above may be used to indicate other meanings in addition to orientation or positional relationships, for example, the term "upper" may also be used to indicate some sort of attachment or connection in some cases. The specific meaning of these terms in this application will be understood by those of ordinary skill in the art as appropriate. Furthermore, the terms "mounted," "configured," "provided," "connected," and "connected" are to be construed broadly. For example, it may be a fixed connection, a removable connection, or a unitary construction; may be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements, or components. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be. Furthermore, the terms "first," "second," and the like, are used primarily to distinguish between different devices, elements, or components (the particular species and configurations may be the same or different), and are not used to indicate or imply the relative importance and number of devices, elements, or components indicated. Unless otherwise indicated, the meaning of "a plurality" is two or more.

The embodiment discloses a 28V power on-off control circuit, as shown in fig. 1, may include:

a switch control module and a discharge module;

the switch control module comprises an optical coupler, a PMOS tube, a current limiting resistor, a first voltage limiting resistor and a second voltage limiting resistor;

the optical coupler is electrically connected with the PMOS tube;

the PMOS tube is electrically connected with the positive electrode of the power supply;

the current limiting resistor is connected with the PMOS tube in parallel;

the first voltage limiting resistor is electrically connected with the optical coupler;

the second voltage limiting resistor is electrically connected with the optical coupler;

the discharging module comprises a polar capacitor, wherein the positive electrode of the polar capacitor is electrically connected with the positive electrode of the power supply, and the negative electrode of the polar capacitor is electrically connected with the common mode inductor.

In the embodiment, the 28V power on-off is realized by adopting a scheme of controlling the on-off of the PMOS tube, and the control signal is output after being isolated by the optocoupler.

Specifically, the 28V power supply is divided, so that the voltage drop between the grid electrode and the source stage of the PMOS tube is ensured to be: (5-12) V, so that the PMOS tube is conducted, and a 28V power supply is connected with a later-stage motor driver, so that 28V conduction control is realized through PMOS conduction. In addition, because the airborne 28V power supply has the requirement of 50ms instantaneous interruption, the conventional design scheme adopts a design scheme of carrying out discharge maintenance by adopting a polar capacitor, the internal resistance of the polar capacitor is about 0.2 omega, the line impedance is 0.05 omega, the allowable voltage drop of the subsequent-stage circuit can normally work by comprehensively considering, and the capacitor selects 1000uF energy storage capacitor, so that the scheme can meet the requirement of 50ms instantaneous interruption through verification.

In addition, the electric mechanism adopting the scheme has completed the test and examination of durability vibration at normal temperature, low temperature (-55 ℃) and high temperature (70 ℃), and X, Y, Z triaxial vibration time of 1h in each axial direction; secondly, the standby state motor of the electric mechanism can be ensured to be in a non-working state, and the loss of the motor driver and the motor is reduced, so that the service lives of the motor driver and the motor are ensured to meet the whole life cycle requirement of the electric mechanism.

In some embodiments, the optocoupler first pin is electrically connected to the first voltage limiting resistor;

the second pin of the optical coupler is grounded;

the third pin of the optical coupler is electrically connected with the second voltage limiting resistor;

and the fourth pin of the optical coupler is electrically connected with the grid electrode of the PMOS tube.

In this embodiment, in order to meet the reliable operation of the motor driver of the 28V power supply system and realize that the motor driver can normally operate under the condition of 50ms instantaneous interruption, after the electric mechanism operates to a designated gear, the control circuit outputs a power-off control signal (KZ) of the motor driver 28V1 to realize power-off control of the motor driver and the motor, so as to ensure that the motor driver and the motor are in an inactive state when the electric mechanism is in a standby state, thereby ensuring that the service lives of the motor driver and the motor meet the whole life cycle requirement of the electric mechanism.

In some embodiments, as shown in fig. 1, the source electrode of the PMOS transistor is electrically connected to the positive electrode of the polar capacitor and the positive electrode of the power supply;

the grid electrode of the PMOS tube is electrically connected with the third pin of the optical coupler;

the drain electrode of the PMOS tube is connected with an output signal.

In this embodiment, the working principle of the P-type MOS transistor is based on the control of the gate voltage to the channel. When the grid voltage is lower than the threshold voltage, the P-type MOS tube is in an off state, and no conductive electrons exist in the channel; when the grid voltage is higher than the threshold voltage, the P-type MOS tube is in a conducting state, and conductive electrons are arranged in a channel. The variation of the gate voltage can be controlled by an external circuit or signal source to control the load current.

In some embodiments, the 28V power on-off control circuit further comprises a first filtering module and a second filtering module.

In some embodiments, the first filtering module is a circuit comprising a common mode inductor, a TVS diode;

the first pin of the common mode inductor is connected with the positive electrode of the power supply;

the second pin of the common mode inductor is grounded;

the third pin of the common mode inductor is electrically connected with the cathode of the TVS diode;

the fourth pin of the common mode inductor is electrically connected with the anode of the TVS diode;

the positive electrode of the TVS diode is electrically connected with the third pin of the common mode inductor, and the negative electrode of the TVS diode is electrically connected with the positive electrode of the power supply.

The second filtering module comprises a differential mode inductor, a first ceramic capacitor and a second ceramic capacitor;

one end of the first ceramic capacitor is electrically connected with the differential mode inductor, and the other end of the first ceramic capacitor is electrically connected with a third pin of the common mode inductor;

one end of the second ceramic capacitor is electrically connected with the other end of the differential mode inductor, and the other end of the second ceramic capacitor is electrically connected with the third pin of the common mode inductor

In this embodiment, the filter circuit is mainly used to suppress spike voltage and spike current generated in the working moment of the 28V motor, prevent pulse interference signals from entering the power supply system, influence the normal operation of other systems, and influence the normal operation of other devices by electromagnetic radiation generated outside.

Specifically, an L-shaped EMC filter circuit is formed by adopting a TVS diode, a common mode inductor, a differential mode inductor, a polar capacitor and a ceramic capacitor, so that voltage spikes and current pulses generated in the moment of starting and braking a motor in the working process of an electric mechanism can be effectively suppressed.

Specifically, TVS selects transient suppression diodes with clamping voltages of 60V and 600W as surge suppression diodes, so that the transient suppression diodes can clamp impulse interference of more than 60V to a later-stage circuit, and the circuit and the module are damaged due to impulse interference after protection; the EMC filter circuit consists of an EMC common mode inductor, a differential mode inductor, a porcelain capacitor, a polarity capacitor and the like; the common mode inductance is 3mH, the differential mode inductance is 22uH, the polarity capacitance is 1000uF, and the porcelain dielectric capacitance is 1uF.

The filtering inductance is designed to be 20kHz in the center frequency of differential mode filtering, so that differential mode interference nearby 20kHz can be filtered, the center frequency of the common mode filtering circuit is designed to be 500kHz, and common mode interference nearby 1MHz due to motor action can be filtered. In addition, the filter circuit can also ensure that the power supply of the electric mechanism 28V is checked through electromagnetic compatibility tests of CE102 and RE 102.

In some embodiments, one end of the current limiting resistor is electrically connected with the source electrode of the PMOS transistor and the differential mode inductor, and the other end of the current limiting resistor is electrically connected with the fourth pin of the optocoupler and the gate electrode of the PMOS transistor;

one end of the first voltage limiting resistor is electrically connected with the first pin of the optical coupler, and the other end of the first voltage limiting resistor is connected with an input signal;

one end of the second voltage limiting resistor is electrically connected with the third pin of the optical coupler, and the other end of the second voltage limiting resistor is grounded.

In this embodiment, the resistor is used to regulate the voltages and currents flowing through the optocoupler and each pole of the PMOS transistor, so as to ensure that the purposes of on-off control and protection of the device can be achieved.

Specifically, the resistance of the current limiting resistor may be set to 1.5kΩ, the resistance of the first voltage limiting resistor is set to 241 Ω, and the resistance of the second voltage limiting resistor is set to 2.2kΩ.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment contains only one independent technical solution, and that such description is provided for clarity only, and that the technical solutions of the embodiments may be appropriately combined to form other embodiments that will be understood by those skilled in the art.

Claims (7)

1. A 28V power on-off control circuit, characterized in that the 28V power on-off control circuit comprises:

a switch control module and a discharge module;

the switch control module comprises an optical coupler, a PMOS tube, a current limiting resistor, a first voltage limiting resistor and a second voltage limiting resistor;

the optical coupler is electrically connected with the PMOS tube;

the PMOS tube is electrically connected with the positive electrode of the power supply;

the current limiting resistor is connected with the PMOS tube in parallel;

the first voltage limiting resistor is electrically connected with the optical coupler;

the second voltage limiting resistor is electrically connected with the optical coupler;

the discharging module comprises a polar capacitor, wherein the positive electrode of the polar capacitor is electrically connected with the positive electrode of the power supply, and the negative electrode of the polar capacitor is electrically connected with the common mode inductor.

2. The 28V power on-off control circuit according to claim 1, wherein a first pin of the optocoupler is electrically connected to the first voltage limiting resistor;

the second pin of the optical coupler is grounded;

the third pin of the optical coupler is electrically connected with the second voltage limiting resistor;

and the fourth pin of the optical coupler is electrically connected with the grid electrode of the PMOS tube.

3. The 28V power on-off control circuit according to claim 2, wherein the source electrode of the PMOS tube is electrically connected with the positive electrode of the polar capacitor and the positive electrode of the power supply;

the grid electrode of the PMOS tube is electrically connected with the third pin of the optical coupler;

the drain electrode of the PMOS tube is connected with an output signal.

4. A 28V power on-off control circuit according to claim 3, wherein the 28V power on-off control circuit further comprises a first filter module and a second filter module.

5. The 28V power on-off control circuit according to claim 4, wherein the first filter module comprises a common mode inductor, a TVS diode;

the first pin of the common mode inductor is connected with the positive electrode of the power supply;

the second pin of the common mode inductor is grounded;

the third pin of the common mode inductor is electrically connected with the cathode of the TVS diode;

the fourth pin of the common mode inductor is electrically connected with the anode of the TVS diode;

the positive electrode of the TVS diode is electrically connected with the third pin of the common mode inductor, and the negative electrode of the TVS diode is electrically connected with the positive electrode of the power supply.

6. The 28V power on-off control circuit according to claim 4, wherein the second filter module comprises a differential mode inductor, a first ceramic capacitor and a second ceramic capacitor;

one end of the first ceramic capacitor is electrically connected with the differential mode inductor, and the other end of the first ceramic capacitor is electrically connected with a third pin of the common mode inductor;

and one end of the second ceramic capacitor is electrically connected with the other end of the differential mode inductor, and the other end of the second ceramic capacitor is electrically connected with the third pin of the common mode inductor.

7. The 28V power on-off control circuit according to claim 6, wherein one end of the current limiting resistor is electrically connected with the PMOS source and the differential mode inductor, and the other end is electrically connected with the fourth pin of the optocoupler and the PMOS gate;

one end of the first voltage limiting resistor is electrically connected with the first pin of the optical coupler, and the other end of the first voltage limiting resistor is connected with an input signal;

one end of the second voltage limiting resistor is electrically connected with the third pin of the optical coupler, and the other end of the second voltage limiting resistor is grounded.