Power supply interruption safety protection circuit

Abstract

A power supply interruption safety protection circuit disclosed by the present invention comprises a time delay circuit used for being connected with a power supply, the time delay circuit comprises a triode, an MOS tube, a resistor assembly and a capacitor, the resistor assembly is composed of a resistor R19, a resistor R21, a resistor R20 and a resistor R22, a common connection end of the resistor R20 and the resistor R22 is connected with a grid electrode G of the MOS tube, and the capacitor is connected with the MOS tube. The input end of the resistor R20 and the common connection end of the drain electrode D of the MOS tube are connected with driving power, the input end of the resistor R19 is connected with control power, and after the control power is established, the capacitor is fully charged, and the triode and the MOS tube are conducted to form a normal driving electric signal; the problem of output delay of control power and driving power and the problem of power supply interruption and damage of power devices can be solved, normal driving signals are ensured to be normal, the circuit is simple and reliable, and the circuit is suitable for products subjected to power supply compatibility assessment.

Description

Technical Field

[0001] This invention relates to the field of control technology for aerospace drives that adapt to power supply compatibility, specifically a power interruption safety protection circuit. Background Technology

[0002] In traditional aerospace products, there are some low-voltage, high-current brushless DC motors where the motor body and controller are integrated. These products have only one power supply / input power source, and both the control power supply and drive power supply are converted from power electricity. In power interruption experiments, the control electricity may power on slower than the drive electricity due to device delays. In this case, the drive electricity will cause the upper and lower transistors of the drive to output simultaneously, which will lead to shoot-through of the upper and lower transistors of the power device. The module will be damaged if the power electricity is present, and the power device is easily damaged if the power supply is interrupted. To address this, a power interruption safety protection circuit is proposed. Summary of the Invention

[0003] The purpose of this invention is to provide a power supply interruption safety protection circuit to solve the problems of control and drive power output delay and power device power supply interruption and damage mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A power interruption safety protection circuit includes a delay circuit for connection to a power supply. The delay circuit includes a transistor, a MOSFET, a resistor assembly, and a capacitor. The resistor assembly consists of resistors R19, R21, R20, and R22, with R20 and R22 connected in series, and R19 and R21 connected in series. The common connection terminal of resistors R20 and R22 is connected to the gate (G) of the MOSFET. The input terminal of resistor R20 is connected to the common connection terminal of the drain (D) of the MOSFET and is connected to a drive current. The collector (C) of the transistor is connected to resistor R22, the emitter (E) of the transistor is grounded (GND), and the base (B) of the transistor is connected to the common connection terminal between resistors R19 and R21. The input terminal of resistor R19 is connected to a control current. When the control current is established, the capacitor is fully charged, and the transistor and MOSFET conduct to form a normal drive signal.

[0005] Furthermore, the MOS transistor is a P-channel field-effect transistor, and a negative voltage is present between the gate and source of the MOS transistor to enable the MOS transistor to be turned on. The transistor is an N-MOS transistor.

[0006] Furthermore, one end of the capacitor and one end of the resistor R21 are grounded to GND, and the other end of the capacitor is connected to the base B of the transistor.

[0007] The beneficial effects of this invention are: This invention uses a delay circuit formed by capacitors, resistors, transistors, and MOSFETs to solve the problems of delay in the output of control and drive circuits, as well as the problem of power device interruption and damage. It ensures that the normal drive signal is normal, and the circuit is simple and reliable, suitable for products that are subject to power supply compatibility testing. Attached Figure Description

[0008] Figure 1 This is a circuit diagram for the power interruption safety protection of the present invention.

[0009] In the diagram: 1. Control circuit; 2. Capacitor; 3. Transistor; 4. Drive circuit; 5. MOSFET. Detailed Implementation

[0010] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0011] Please see Figure 1 This invention provides a technical solution: a power interruption safety protection circuit, including a delay circuit for connection to the power supply. The delay circuit includes a transistor 3, a MOSFET 5, a resistor assembly, and a capacitor 2. The resistor assembly consists of resistors R19, R21, R20, and R22, with R20 and R22 connected in series, and R19 and R21 connected in series. The common connection terminal of resistors R20 and R22 is connected to the gate G of the MOSFET 5. The input terminal of resistor R20 is connected to the common connection terminal of the drain D of MOSFET 5 and connected to drive circuit 4. The collector C of transistor 3 is connected to resistor R22. The emitter E of transistor 3 is grounded to GND, and the base B of transistor 3 is connected to the common connection terminal between resistors R19 and R21. The input terminal of resistor R19 is connected to control circuit 1. The output terminal of control circuit 1 is connected to diode D5, and the input terminal of diode D5 is connected to the base B of transistor 3.

[0012] It should be noted that after control circuit 1 is established, capacitor 2 is fully charged, transistor 3 and MOSFET 5 are turned on to form a normal drive circuit 4 signal; capacitor 2 is labeled C50, and transistor 3 is labeled Q1; preferably, the power supply is a 28V power supply, which is converted to 15V by the power module, and then converted to 5V for control circuit 1. After the 5V control circuit 1 is established, capacitor 2 is fully charged, transistor 3 is turned on, the resistance of resistor R22 is larger than that of resistor R20, there is a negative voltage between the gate and source of MOSFET 5, MOSFET 5 is turned on, and the 15V drive circuit 4 is established. There is a delay between control circuit 1 and drive circuit 4, and the problem caused by power interruption will be solved at this time.

[0013] In this embodiment, MOSFET 5 is a P-channel MOSFET. A negative voltage exists between the gate and source of MOSFET 5 to enable MOSFET 5 to turn on, that is, a negative voltage exists between the gate G and source S of MOSFET 5. Transistor 3 is an N-MOSFET, and transistor 3 adopts the 2N2222AS-G type MOSFET. Among them, one end of capacitor 2 and resistor R21 are grounded to GND, and the other end of capacitor 2 is connected to the base B of transistor 3. This power interruption safety protection circuit ensures that there is only one power input, which solves the problem of power device damage due to power interruption in products with small space structure that cannot add more protection measures. It solves the problem of easy damage to power devices due to power interruption without the need for software algorithms.

[0014] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0015] The above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be understood that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. In the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can refer to a mechanical connection; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two components or the interaction between two components. Among these, there are various ways of detachable installation, such as by using a combination of plug-in and snap-fit, or by using bolt connections, etc.

[0016] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A power interruption safety protection circuit, characterized by: The delay circuit for connecting with power supply includes a transistor, a MOS tube, a resistance component and a capacitor, the resistance component is composed of resistance R19, resistance R21, resistance R20 and resistance R22, resistance R20 and resistance R22 are connected in series, resistance R19 and resistance R21 are connected in series, the common connection end of resistance R20 and resistance R22 is connected with the gate G of the MOS tube, the input end of resistance R20 is connected with the common connection end of the drain D of the MOS tube, the collector C of the transistor is connected with resistance R22, the emitter E of the transistor is grounded GND, the common connection end between resistance R19 and resistance R21 is connected with the base B of the transistor, and the input end of resistance R19 is connected with control electricity; when the control electricity is established, the capacitor is fully charged, the transistor and the MOS tube are turned on to form a normal driving electric signal.

2. The power interruption safety protection circuit according to claim 1, wherein: The MOS tube is a P-channel field effect tube, the gate and the source of the MOS tube have a negative voltage to realize the opening of the MOS tube, and the transistor is an N-MOS tube.

3. The power interruption safety protection circuit according to claim 1, wherein: The capacitor and one end of resistance R21 are grounded GND, and the other end of the capacitor is connected with the base B of the transistor.

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