Passive overvoltage stabilizing circuit

Abstract

The utility model discloses a passive overvoltage stabilizing circuit, which comprises a first voltage stabilizing diode ZD1, a first divider resistor R1, a second divider resistor R2 and a field effect transistor Q. The positive electrode of the first voltage stabilizing diode ZD1 is connected with the grid electrode of the field effect transistor Q through the first divider resistor R1, and the negative electrode of the first voltage stabilizing diode ZD1 is connected with the grid electrode of the field effect transistor Q through the second divider resistor R2. A grid electrode of the field effect transistor Q is connected with a source electrode of the field effect transistor Q through the second divider resistor R2, a drain electrode of the field effect transistor Q is connected with a negative electrode of the first voltage stabilizing diode ZD1, and the negative electrode of the first voltage stabilizing diode ZD1 and the source electrode of the field effect transistor Q serve as a power supply positive electrode end and a power supply negative electrode end respectively and are connected to a direct current power grid in parallel. The passive overvoltage stabilizing circuit is simple and practical in design, does not need an external power supply, is directly connected in parallel to a direct-current power grid during application, can quickly absorb high-voltage surge appearing in the direct-current power grid, and stabilizes the voltage of the direct-current power grid.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, and in particular provides a passive overvoltage stabilizing circuit. Background Art

[0002] The power generation system on most military vehicles is a fuel-powered uncontrolled rectifier output structure. The DC power output by the power generation system is used to supply DC power to the entire vehicle through the distribution box; generally, the rated DC voltage output is 10 to 20KW / 14V and 28V. The voltage stabilization working principle of the above power generation system is: the uncontrolled rectifier controller controls the output power of the fuel engine according to the output voltage, thereby achieving the stability of the rated voltage. However, in the actual working environment, the load changes are instantaneous, such as the start and stop of the heating device, air conditioning device, DC motor and other equipment, and the voltage fluctuation caused will be fed back to the controller, and the controller will adjust the power output of the engine to restore the rated voltage. However, due to the delay in the engine power response, when the load is suddenly unloaded, the line current cannot be discharged in time, which will push up the grid voltage. This is a safety hazard for a large number of expensive key electronic equipment installed in military vehicles, which may cause the burning of airborne equipment and affect the reliability and safety of the entire vehicle.

[0003] In addition, since the fuel-powered power generation system with uncontrolled rectification is based on a large closed-loop method in which voltage controls the speed, the loop has many links such as voltage acquisition, controller to communication, communication docking with the engine controller, and controller controlling fuel injection and air intake. If there is a problem with any loop component, there is a risk of excessive voltage out of control, which will pose a threat to the reliability and safety of the entire vehicle.

[0004] For a long time, measures to ensure the stability and safety of vehicle power grids have basically relied on quality control of all links in the power generation system, that is, completely relying on the reliability and stability of the fuel power generation system, without a second voltage prevention safety measure. In actual vehicle operation, the voltage of the engine controller fluctuates frequently when it is hit or the motor load is suddenly increased or decreased. Due to efficiency and volume factors, it is impossible to add additional electronic voltage stabilization equipment between the power equipment and the distribution box. Therefore, it is impossible to ensure the safety of the expensive and critical on-board electronic equipment of the vehicle.

[0005] To this end, developing a passive overvoltage stabilization circuit that is compact and easy to install to quickly absorb high-voltage surges in the power grid, thereby stabilizing the DC power grid and preventing expensive electronic equipment connected to the downstream from being damaged or abnormal due to voltage increases has become an urgent issue to be solved in order to resolve traditional safety and reliability issues. Utility Model Content

[0006] In view of this, the purpose of the utility model is to provide a passive overvoltage stabilization circuit to solve the problem that the conventional fuel power generation system cannot avoid the instantaneous overvoltage, which may cause damage or abnormality to the subsequent electronic equipment.

[0007] The technical solution provided by the utility model is: a passive overvoltage stabilization circuit, comprising: a first voltage stabilizing diode ZD1, a first voltage dividing resistor R1, a second voltage dividing resistor R2 and a field effect transistor Q, wherein the anode of the first voltage stabilizing diode ZD1 is connected to the gate of the field effect transistor Q via the first voltage dividing resistor R1, the gate of the field effect transistor Q is connected to the source of the field effect transistor Q via the second voltage dividing resistor R2, the drain of the field effect transistor Q is connected to the cathode of the first voltage stabilizing diode ZD1, and the cathode of the first voltage stabilizing diode ZD1 and the source of the field effect transistor Q are respectively connected in parallel to a DC power grid as a positive power supply terminal and a negative power supply terminal.

[0008] Preferably, the passive overvoltage stabilization circuit further includes a second zener diode ZD2, wherein the anode of the second zener diode ZD2 is connected to the source of the field effect transistor Q, and the cathode of the second zener diode ZD2 is connected to the gate of the field effect transistor Q.

[0009] Further preferably, the passive overvoltage stabilization circuit further includes a third resistor R3, and the third resistor R3 is connected between the gate of the field effect transistor Q and the first voltage dividing resistor R1.

[0010] Further preferably, a fuse F is further provided between the cathode of the first voltage stabilizing diode ZD1 and the drain of the field effect transistor Q.

[0011] The passive overvoltage stabilization circuit provided by the utility model is simple and practical in design, does not require an external power supply, can be directly connected to the DC power grid when applied, can quickly absorb the high-voltage surge in the DC power grid, and thus achieve the effect of stabilizing the DC power grid and preventing expensive electronic equipment connected at the later stage from being damaged or abnormal due to voltage increase. The circuit reduces the probability of sudden invisible accidents, significantly improves the safety and reliability of DC power grid transmission, and has very wide social and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The present invention is further described in detail below with reference to the accompanying drawings and implementation modes:

[0013] Figure 1 The present invention provides a circuit diagram of a passive overvoltage stabilization circuit. DETAILED DESCRIPTION

[0014] The present invention will be further explained below in conjunction with specific implementation schemes, but the present invention is not limited thereto.

[0015] like Figure 1 As shown, the utility model provides a passive overvoltage stabilization circuit, including: a first voltage stabilizing diode ZD1, a first voltage dividing resistor R1, a second voltage dividing resistor R2 and a field effect transistor Q, wherein the anode of the first voltage stabilizing diode ZD1 is connected to the gate of the field effect transistor Q via the first voltage dividing resistor R1, the gate of the field effect transistor Q is connected to the source of the field effect transistor Q via the second voltage dividing resistor R2, the drain of the field effect transistor Q is connected to the cathode of the first voltage stabilizing diode ZD1, and the cathode of the first voltage stabilizing diode ZD1 and the source of the field effect transistor Q are respectively connected in parallel to a DC power grid as a positive power supply terminal and a negative power supply terminal.

[0016] The passive overvoltage stabilization circuit mainly utilizes the characteristic that the conductivity of the field effect tube can be changed by the gate voltage. When the gate voltage changes, the density of carriers in the channel can be changed due to the electric field between the gate and the channel, thereby achieving the effect that the current at both ends changes with the change of the gate voltage. In combination with this circuit, the input voltage is simultaneously loaded to the drain and source ends of the field effect tube and the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2, wherein R1 and R2 constitute a voltage-dividing circuit, and the voltage after voltage division drives the field effect tube, and the current intensity of the field effect tube is consistent with the voltage division value, that is, the higher the input voltage, the greater the circuit current consumed by this circuit, and the circuit voltage will change according to the current consumed. When the voltage reaches the voltage value that needs to be stabilized, the first voltage-stabilizing diode ZD1 is turned off, the voltage-dividing circuit voltage-dividing cut-off field effect tube is turned off, and the voltage is maintained at the rated voltage state, thereby finally achieving the purpose of voltage stabilization.

[0017] Because the input resistance of the field effect tube is very high, and the capacitance between the gate and the source is very small, it is easy to be charged by the induction of external electromagnetic fields or static electricity. A small amount of charge may form a very high voltage on the inter-electrode capacitance, thus causing damage to the field effect tube. As an improvement to the technical solution, such as Figure 1 As shown, the passive overvoltage stabilization circuit also includes a second zener diode ZD2, wherein the anode of the second zener diode ZD2 is connected to the source of the field effect transistor Q, and the cathode of the second zener diode ZD2 is connected to the gate of the field effect transistor Q. By adding the second zener diode ZD2 between the gate and source of the field effect transistor Q, the damage of the field effect transistor Q caused by static electricity can be effectively suppressed, thereby protecting the field effect transistor Q.

[0018] As an improvement of the technical solution, Figure 1As shown, the passive overvoltage stabilization circuit also includes a third resistor R3, and the third resistor R3 is connected between the gate of the field effect tube Q and the first voltage divider resistor R1. By setting the third resistor R3, the field effect tube Q can be prevented from oscillating during the conduction and cutoff process, thereby reducing the possible switching loss of the field effect tube Q.

[0019] As an improvement of the technical solution, Figure 1 As shown, a fuse F is also arranged between the cathode of the first voltage stabilizing diode ZD1 and the drain of the field effect transistor Q to protect the field effect transistor from being damaged when overloaded or overcurrent occurs. The selection of the fuse is based on the maximum current in the design index of the circuit.

[0020] The specific implementation methods of the present utility model are written in a progressive manner, emphasizing the differences between the various implementation methods, and the similar parts thereof can be referenced to each other.

[0021] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A passive overvoltage stabilization circuit, characterized in that: include: A first voltage-regulating diode ZD1, a first voltage-dividing resistor R1, a second voltage-dividing resistor R2 and a field effect transistor Q, wherein the anode of the first voltage-regulating diode ZD1 is connected to the gate of the field effect transistor Q via the first voltage-dividing resistor R1, the gate of the field effect transistor Q is connected to the source of the field effect transistor Q via the second voltage-dividing resistor R2, the drain of the field effect transistor Q is connected to the cathode of the first voltage-regulating diode ZD1, and the cathode of the first voltage-regulating diode ZD1 and the source of the field effect transistor Q are respectively connected in parallel to a DC power grid as a positive power supply terminal and a negative power supply terminal.

2. The passive overvoltage stabilization circuit according to claim 1, characterized in that: It also includes a second voltage stabilizing diode ZD2, wherein the anode of the second voltage stabilizing diode ZD2 is connected to the source of the field effect transistor Q, and the cathode of the second voltage stabilizing diode ZD2 is connected to the gate of the field effect transistor Q.

3. The passive overvoltage stabilization circuit according to claim 1, characterized in that: The device further includes a third resistor R3 connected between the gate of the field effect transistor Q and the first voltage dividing resistor R1.

4. The passive overvoltage stabilization circuit according to claim 1, characterized in that: A fuse F is also provided between the cathode of the first voltage stabilizing diode ZD1 and the drain of the field effect transistor Q.

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