Rapid discharge circuit and wide voltage output device

Abstract

The invention relates to a quick discharge circuit and wide voltage output equipment, and aims to enable a voltage output circuit to realize wide-range adjustable voltage output and meet the requirement that the output voltage can be quickly reduced at the same time. The load value of the wide voltage output sub-circuit is further judged, and when the load of the wide voltage output sub-circuit is higher than a preset load threshold value, the voltage drop detection sub-circuit is prevented from outputting a high level to the load switching sub-circuit; the voltage drop detection sub-circuit is used for detecting the voltage change of the wide voltage output sub-circuit, and outputting a high level to the load switching sub-circuit when the voltage of the wide voltage output sub-circuit drops; and the load switching sub-circuit is used for receiving the high level output of the voltage drop detection sub-circuit, so that a preset discharge load is connected into the wide voltage output sub-circuit, and rapid discharge of an output capacitor in the wide voltage output sub-circuit is realized.

Description

Technical Field

[0001] The present invention relates to the field of electronic power technology, in particular to a fast discharge circuit and a wide voltage output device. Background Art

[0002] With the in-depth development and widespread application of electronic power technology, more and more technical fields require the application of power supplies with adjustable output voltage. In particular, in technical fields such as instrument manufacturing and medical equipment, the power supply needs to have a wide output voltage adjustment range, so the demand for power supply circuits with a wide range of output voltage is increasing.

[0003] In order to achieve rapid regulation of the output voltage, the existing wide-range voltage output circuit generally discharges the output capacitor in the circuit by connecting a load when the output voltage is adjusted to decrease, or discharges the output capacitor through a software control signal. Since the cost of using software to control the discharge of the output capacitor is too high, setting a low-resistance load to enable the output capacitor to discharge quickly will affect the adjustment range of the output voltage regulation of the voltage output circuit. Even if the capacitor discharge speed and the voltage output range are comprehensively considered, and a load with a suitable resistance value is added to the circuit, the load will work in the wide-range voltage output circuit for a long time, which will increase the circuit loss and reduce the efficiency of voltage output and voltage regulation. Therefore, the speed at which the existing wide-range voltage output circuit adjusts the output voltage cannot meet the needs of the application field. How to simply and effectively enable the circuit to achieve a wide-range adjustable voltage output while being able to quickly adjust the output voltage is an urgent problem to be solved in the design and application of a wide-range adjustable output voltage source. Summary of the invention

[0004] The purpose of the present invention is to enable a voltage output circuit to achieve a wide range of adjustable voltage output while satisfying the requirement that the output voltage can be quickly adjusted down.

[0005] In order to achieve the above-mentioned object, the first aspect of the present invention provides a fast discharge circuit, comprising a wide voltage output subcircuit, a current sampling subcircuit, a voltage drop detection subcircuit and a load switching subcircuit; wherein the wide voltage output subcircuit is electrically connected to the current sampling subcircuit, the voltage drop detection subcircuit and the load switching subcircuit respectively; the current sampling subcircuit is electrically connected to the voltage drop detection subcircuit and the load switching subcircuit respectively; the voltage drop detection subcircuit is electrically connected to the load switching subcircuit;

[0006] The current sampling subcircuit is used to sample the current of the wide voltage output subcircuit, and then determine the load value of the wide voltage output subcircuit, and when the load of the wide voltage output subcircuit is higher than a preset load threshold, prevent the voltage drop detection subcircuit from outputting a high level to the load switching subcircuit;

[0007] The voltage drop detection subcircuit is used to detect the voltage change of the wide voltage output subcircuit, and when the voltage of the wide voltage output subcircuit drops, output a high level to the load switching subcircuit;

[0008] The load switching subcircuit is used to receive the high level output of the voltage drop detection subcircuit, and then connect the preset discharge load to the wide voltage output subcircuit to achieve rapid discharge of the wide voltage output subcircuit.

[0009] The above-mentioned fast discharge circuit, by briefly connecting a low-resistance discharge load during the process of the wide voltage output subcircuit output voltage decreasing, enables the wide voltage output subcircuit to achieve a wide range of adjustable voltage output while satisfying the requirement that the output voltage can be quickly adjusted down. Considering that the connection of the discharge load to the wide voltage output subcircuit in the working state other than the output voltage decreasing will increase the circuit loss and affect the adjustment range of the output voltage regulation of the voltage output circuit, the above-mentioned fast discharge circuit uses a voltage drop detection subcircuit to detect the voltage change of the wide voltage output subcircuit, so that only when the voltage of the wide voltage output subcircuit decreases, the voltage drop detection subcircuit will generate a high-level signal to turn on the load switching subcircuit, so as to connect the discharge load to the wide voltage output subcircuit to complete the fast discharge. Furthermore, considering that when the wide voltage output subcircuit has a built-in high-resistance load, the discharge load should not be connected to increase the circuit loss, the above-mentioned fast discharge circuit uses the current sampling subcircuit to detect and determine the load value of the wide voltage output subcircuit, so that when the load value of the wide voltage output subcircuit is too high, the output end of the current sampling subcircuit generates a low-level signal, thereby pulling down the input end level of the load switching subcircuit, preventing the voltage drop detection subcircuit from outputting a high level to the load switching subcircuit, so that the load switching subcircuit is cut off, and the discharge load is no longer connected to the wide voltage output subcircuit.

[0010] Therefore, the above-mentioned fast discharge circuit not only helps the output capacitor to discharge quickly by connecting a low-resistance discharge load for a short time, thereby avoiding the low-resistance load from affecting the adjustment range of the output voltage of the wide voltage output circuit, but also avoids the discharge load from being connected to the circuit when the built-in load value is too large or the output voltage drops, by detecting the built-in load value and output voltage changes of the wide voltage output circuit, thereby reducing circuit losses and improving the working efficiency of the wide voltage output circuit.

[0011] In a possible implementation, the voltage drop detection subcircuit includes a first resistor, a second resistor, a first diode, a first capacitor, a PNP transistor and a third resistor, wherein:

[0012] A first end of the first resistor is electrically connected to a voltage output end of the wide voltage output subcircuit, and a second end is electrically connected to an anode of the first diode and a first end of the second resistor respectively;

[0013] The second end of the second resistor is electrically connected to the first end of the first capacitor and the ground end respectively;

[0014] The cathode of the first diode is electrically connected to the second end of the first capacitor;

[0015] The emitter of the PNP transistor is electrically connected to the cathode of the first diode and the second end of the first capacitor respectively, the base is electrically connected to the second end of the third resistor, and the collector is electrically connected to the load switching subcircuit;

[0016] The first end of the third resistor is electrically connected to the voltage output end of the wide voltage output subcircuit.

[0017] It should also be noted that the first capacitor is an electrolytic capacitor, also known as an EC capacitor; the first diode is a Schottky diode, also known as a hot carrier diode, which is a semiconductor diode with a low forward voltage drop and very fast switching action. When current flows through the Schottky diode, a voltage drop is generated on the Schottky diode terminal, usually between 0.15V and 0.45V.

[0018] Specifically, when the voltage drop detection subcircuit is working, the output voltage of the wide voltage output subcircuit is divided by the first resistor and the second resistor, and then the first capacitor is charged. When the capacitor is fully charged, the absolute value of its capacitor voltage is equal to the Schottky diode voltage drop, reaching the voltage sampling point. When the output voltage of the wide voltage output subcircuit drops, the emitter voltage of the PNP transistor is equal to the capacitor voltage of the first capacitor, and the base voltage of the PNP transistor is lower than the emitter voltage. At this time, the PNP transistor is turned on, and the collector voltage of the PNP transistor is raised, thereby generating a high-level signal at the output end of the voltage drop detection subcircuit.

[0019] In this implementation, the charging and discharging characteristics of the capacitor and the conduction characteristics of the transistor are utilized so that the voltage drop detection subcircuit charges the capacitor when the output voltage of the wide voltage output subcircuit remains unchanged or increases, so that when the output voltage of the wide voltage output subcircuit drops, the transistor is turned on to generate a high-level signal at the output end of the voltage drop detection subcircuit, thereby responding to the drop in the output voltage of the wide voltage output subcircuit and completing the detection of the output voltage drop.

[0020] In a possible implementation, the load switching subcircuit includes a fourth resistor, a fifth resistor, an N-channel MOS transistor and a discharge load, wherein:

[0021] A first end of the fourth resistor is electrically connected to the collector of the PNP transistor, and a second end thereof is electrically connected to the gate of the N-channel MOS transistor;

[0022] The first end of the fifth resistor is electrically connected to the collector of the PNP transistor, and the second end is electrically connected to the source and the ground of the N-channel MOS transistor respectively;

[0023] The drain of the N-channel MOS tube is electrically connected to the first end of the discharge load;

[0024] The second end of the discharge load is electrically connected to the voltage output end of the wide voltage output subcircuit.

[0025] Specifically, when the input end of the load switching subcircuit is at a low level, the N-channel MOS transistor is turned off, and the discharge load is not connected to the wide voltage output subcircuit. When the input end of the load switching subcircuit receives a high-level signal from the voltage drop detection subcircuit, the gate voltage of the N-channel MOS transistor is raised, so that the MOS transistor is turned on, and the discharge load is connected to the wide voltage output subcircuit to discharge the output capacitor; at the same time, the fifth resistor discharges the first capacitor through the PNP transistor until the discharge voltage is equal to the voltage sampling point, so that the emitter voltage of the PNP transistor is refreshed, and then the PNP transistor is turned off again, and the voltage drop detection subcircuit no longer outputs a high-level signal. At this time, the N-channel MOS transistor is turned off again, and the discharge load is no longer connected to the wide voltage output subcircuit.

[0026] In this implementation, the conduction characteristics of the MOS tube and the charge and discharge characteristics of the capacitor are utilized so that when the output voltage of the wide voltage output subcircuit drops, the output end of the voltage drop detection subcircuit generates a high-level signal to connect the discharge load of the load switching subcircuit to the wide voltage output subcircuit to quickly discharge the output capacitor, and after the discharge is completed, the discharge load is disconnected from the wide voltage output subcircuit again to prevent the discharge load from increasing the circuit loss of the wide voltage output subcircuit.

[0027] In a possible implementation, the current sampling subcircuit includes a current sampling module and a sampling voltage comparison module; wherein the current sampling module is electrically connected to the wide voltage output subcircuit and the sampling voltage comparison module respectively; the sampling voltage comparison module is electrically connected to a preset reference voltage, the current sampling module, the voltage drop detection subcircuit and the load switching subcircuit respectively;

[0028] The current sampling module is used to sample the current of the wide voltage output subcircuit, and then convert it into a sampled voltage and output it to the sampled voltage comparison module;

[0029] The sampling voltage comparison module is used to divide the preset reference voltage to obtain a comparison voltage, and then compare it with the sampling voltage. When the sampling voltage is greater than the comparison voltage, it is considered that the load of the wide voltage output sub-circuit is higher than the preset load threshold, and then a low-level output is generated to lower the output level of the load switching sub-circuit, so as to prevent the voltage drop detection sub-circuit from outputting a high level to the load switching sub-circuit.

[0030] In a possible implementation, the current sampling module includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, and a first operational amplifier, wherein:

[0031] A first end of the sixth resistor is electrically connected to the negative current output terminal of the wide voltage output subcircuit, and a second end thereof is electrically connected to the inverting terminal of the first operational amplifier;

[0032] A first end of the seventh resistor is electrically connected to the current positive output end of the wide voltage output subcircuit, and a second end is electrically connected to the non-inverting end of the first operational amplifier;

[0033] The first end of the eighth resistor is electrically connected to the in-phase terminal of the first operational amplifier, and the second end is electrically connected to the ground terminal;

[0034] A first end of the second capacitor is electrically connected to a first end of the eighth resistor, and a second end of the second capacitor is electrically connected to a second end of the eighth resistor;

[0035] A first end of the third capacitor is electrically connected to the inverting end of the first operational amplifier, and a second end of the third capacitor is electrically connected to the non-inverting end of the first operational amplifier;

[0036] A first end of the ninth resistor is electrically connected to the inverting end of the first operational amplifier, and a second end of the ninth resistor is electrically connected to the output end of the first operational amplifier;

[0037] A first end of the fourth capacitor is electrically connected to a first end of the ninth resistor, and a second end of the fourth capacitor is electrically connected to a second end of the ninth resistor;

[0038] A first end of the tenth resistor is electrically connected to the output end of the first operational amplifier, and a second end of the tenth resistor is electrically connected to the sampling voltage comparison module;

[0039] The first end of the fifth capacitor is electrically connected to the second end of the tenth resistor, and the second end of the fifth capacitor is electrically connected to the ground.

[0040] In this implementation, the positive current output and the negative current output of the wide voltage output subcircuit are sampled, and the voltage difference between the two current output terminals is amplified as a sampled voltage output through a first operational amplifier. The load resistance value in the wide voltage output subcircuit is determined by observing the change in the sampled voltage, thereby improving the accuracy of determining the load resistance value in the wide voltage output subcircuit.

[0041] In a possible implementation, the sampling voltage comparison module includes an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a sixth capacitor, a seventh capacitor, a second operational amplifier, and a second diode, wherein:

[0042] The first end of the eleventh resistor is electrically connected to a preset reference voltage, and the second end is electrically connected to the first end of the twelfth resistor;

[0043] The second end of the twelfth resistor is electrically connected to the ground end;

[0044] The first end of the sixth capacitor is electrically connected to the first end of the twelfth resistor, and the second end of the sixth capacitor is electrically connected to the second end of the twelfth resistor;

[0045] The first end of the thirteenth resistor is electrically connected to the first end of the twelfth resistor, and the second end is electrically connected to the non-inverting terminal of the second operational amplifier;

[0046] The first end of the fourteenth resistor is electrically connected to the second end of the tenth resistor, and the second end is electrically connected to the inverting end of the second operational amplifier and the first end of the seventh capacitor respectively;

[0047] The second end of the seventh capacitor is electrically connected to the output end of the second operational amplifier;

[0048] The cathode of the second diode is electrically connected to the output end of the second operational amplifier, and the anode of the second diode is electrically connected to the first end of the fourth resistor.

[0049] Specifically, a voltage comparison circuit is formed by a second operational amplifier, wherein the sampling voltage is located at the inverting terminal of the second operational amplifier, and the comparison voltage is located at the non-inverting terminal of the second operational amplifier. When the sampling voltage is less than the comparison voltage, the second operational amplifier outputs a high-level signal to the cathode of the second diode to reversely cut off the second diode. At this time, when the voltage drop detection subcircuit outputs a high-level signal, since the second diode is reversely cut off, the high-level signal is output from the voltage drop detection subcircuit to the load switching subcircuit. When the sampling voltage is greater than the comparison voltage, the second operational amplifier outputs a low-level signal to the cathode of the second diode to forward conduct the second diode. At this time, when the voltage drop detection subcircuit outputs a high-level signal, since the second diode is forwardly conducted, the high-level signal is pulled down through the second diode path, so that the level of the output end of the load switching subcircuit is always low.

[0050] In this implementation, an operational amplifier is used to form a voltage comparison circuit. By comparing the sampling voltage with the comparison voltage, it is determined whether the load of the wide voltage output sub-circuit is higher than the load threshold. The level signal output by the operational amplifier is further combined with the conduction characteristics of the diode to prevent the discharge load from being connected to the wide voltage output sub-circuit when the built-in load value of the wide voltage output sub-circuit is too large, thereby reducing circuit losses and improving the working efficiency of the wide voltage output circuit.

[0051] In a possible implementation, the N-channel MOS transistor may be replaced by an NPN transistor, wherein:

[0052] The collector of the NPN transistor is electrically connected to the second end of the fifth resistor and the ground end respectively;

[0053] The base of the NPN transistor is electrically connected to the second end of the fourth resistor;

[0054] The emitter of the NPN transistor is electrically connected to the first end of the discharge load.

[0055] In this implementation, when the input end of the load switching subcircuit is at a low level, the NPN transistor is cut off, and the discharge load is not connected to the wide voltage output subcircuit. When the input end of the load switching subcircuit receives a high level signal from the voltage drop detection subcircuit, the base voltage of the NPN transistor is raised, so that the NPN transistor is turned on, and the discharge load is connected to the wide voltage output subcircuit to discharge the output capacitor; at the same time, the fifth resistor discharges the first capacitor through the PNP transistor until the discharge voltage is equal to the voltage sampling point, so that the emitter voltage of the PNP transistor is refreshed, and then the PNP transistor is cut off again, and the voltage drop detection subcircuit no longer outputs a high level signal. At this time, the NPN transistor is cut off again, and the discharge load is no longer connected to the wide voltage output subcircuit.

[0056] In one possible implementation, the resistance value of the discharge load can be adjusted; when the resistance value of the discharge load increases, the rapid discharge speed of the wide voltage output subcircuit is relatively slowed down; when the resistance value of the discharge load decreases, the rapid discharge speed of the wide voltage output subcircuit is relatively accelerated.

[0057] It should also be noted that the adjusting the resistance value of the discharge load includes replacing a load with a different resistance value to adjust the resistance value, or using a variable resistor as the discharge load.

[0058] In this implementation, the magnitude of the current during rapid discharge of the output capacitor is changed by changing the resistance value of the discharge load, thereby achieving adjustment or control of the rapid discharge speed of the wide voltage output sub-circuit.

[0059] In one possible implementation, the capacitance value of the first capacitor can be adjusted; when the capacitance value of the first capacitor increases, the fast discharge time of the wide voltage output subcircuit is relatively increased; when the capacitance value of the first capacitor decreases, the fast discharge time of the wide voltage output subcircuit is relatively reduced.

[0060] It should also be noted that the adjusting the capacitance value of the first capacitor includes replacing a capacitor with a different capacitance value to adjust the capacitance value, or using a variable capacitor as the first capacitor.

[0061] In this implementation, the energy storage capacity of the first capacitor is changed by changing the capacitance value of the first capacitor, so as to change the time for the fifth resistor to discharge the first capacitor through the PNP transistor, thereby changing the time for the voltage drop detection subcircuit to output a high-level signal to connect the discharge load to the wide voltage output subcircuit, thereby achieving adjustment or control of the rapid discharge time of the wide voltage output subcircuit.

[0062] A second aspect of the present invention provides a wide voltage output device, comprising a fast discharge circuit as described in any implementation of the first aspect.

[0063] A fast discharge circuit and a wide voltage output device provided by the present invention have at least the following advantages compared with the prior art:

[0064] By briefly connecting a low-resistance discharge load to help the output capacitor discharge quickly, the low-resistance load is prevented from affecting the adjustment range of the output voltage regulation of the wide voltage output circuit. By detecting the built-in load value and output voltage changes of the wide voltage output circuit, the discharge load is prevented from being connected to the circuit when the built-in load value is too large or the output voltage drops, thereby reducing circuit losses and improving the working efficiency of the wide voltage output circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1is a structural schematic diagram of a fast discharge circuit provided by an embodiment of the present invention;

[0066] Figure 2 is a structural schematic diagram of another fast discharge circuit provided by an embodiment of the present invention;

[0067] Figure 3 is a schematic structural diagram of a voltage drop detection subcircuit provided by an embodiment of the present invention;

[0068] Figure 4 is a structural schematic diagram of a load switching sub-circuit provided by an embodiment of the present invention;

[0069] Figure 5 is a structural schematic diagram of a current sampling module provided by an embodiment of the present invention;

[0070] Figure 6 is a structural diagram of a sampling voltage comparison module provided by an embodiment of the present invention;

[0071] Figure 7 is a structural schematic diagram of another fast discharge circuit provided by an embodiment of the present invention;

[0072] Among them, 110, wide voltage output subcircuit; 120, current sampling subcircuit; 130, voltage drop detection subcircuit; 140, load switching subcircuit; 210, current sampling module; 220, sampling voltage comparison module. DETAILED DESCRIPTION

[0073] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0074] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present invention belongs. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0075] like Figure 1The figure is a schematic diagram of the structure of a fast discharge circuit provided by an embodiment of the present invention, the circuit includes a wide voltage output subcircuit 110, a current sampling subcircuit 120, a voltage drop detection subcircuit 130 and a load switching subcircuit 140; wherein the wide voltage output subcircuit 110 is electrically connected to the current sampling subcircuit 120, the voltage drop detection subcircuit 130 and the load switching subcircuit 140 respectively; the current sampling subcircuit 120 is electrically connected to the voltage drop detection subcircuit 130 and the load switching subcircuit 140 respectively; the voltage drop detection subcircuit 130 is electrically connected to the load switching subcircuit 140;

[0076] The current sampling subcircuit 120 is used to sample the current of the wide voltage output subcircuit 110, and then determine the load value of the wide voltage output subcircuit 110. When the load of the wide voltage output subcircuit 110 is higher than a preset load threshold, the voltage drop detection subcircuit 130 is prevented from outputting a high level to the load switching subcircuit 140.

[0077] The voltage drop detection subcircuit 130 is used to detect the voltage change of the wide voltage output subcircuit 110, and when the voltage of the wide voltage output subcircuit 110 drops, it outputs a high level to the load switching subcircuit 140;

[0078] The load switching subcircuit 140 is used to receive the high level output of the voltage drop detection subcircuit, and then connect the preset discharge load R15 to the wide voltage output subcircuit 110 to achieve rapid discharge of the wide voltage output subcircuit 110.

[0079] like Figure 2 FIG. 1 is a schematic diagram of the structure of another fast discharge circuit provided by an embodiment of the present invention, wherein the circuit includes a wide voltage output subcircuit 110, a current sampling subcircuit 120, a voltage drop detection subcircuit 130 and a load switching subcircuit 140; wherein the current sampling subcircuit includes a current sampling module 210 and a sampling voltage comparison module 220; the current sampling module 210 is electrically connected to the wide voltage output subcircuit and the sampling voltage comparison module 220 respectively; the sampling voltage comparison module 220 is electrically connected to a preset reference voltage, the current sampling module 210, the voltage drop detection subcircuit 130 and the load switching subcircuit 140 respectively;

[0080] The current sampling module 210 is used to sample the current of the wide voltage output subcircuit 110, and then convert it into a sampled voltage and output it to the sampled voltage comparison module 220;

[0081] The sampling voltage comparison module 220 is used to divide the preset reference voltage to obtain a comparison voltage, and then compare it with the sampling voltage. When the sampling voltage is greater than the comparison voltage, it is considered that the load of the wide voltage output subcircuit 110 is higher than the preset load threshold, and then a low-level output is generated to lower the output level of the load switching subcircuit 140, so as to prevent the voltage drop detection subcircuit 130 from outputting a high level to the load switching subcircuit 140.

[0082] like Figure 3 FIG. 1 is a schematic diagram of a voltage drop detection subcircuit 130 provided in an embodiment of the present invention, including a first resistor R1, a second resistor R2, a first diode D1, a first capacitor C1, a PNP transistor V1 and a third resistor R3, wherein:

[0083] The first end of the first resistor R1 is connected to the voltage output terminal V of the wide voltage output sub-circuit 110. out The second end is electrically connected to the anode of the first diode D1 and the first end of the second resistor R2 respectively;

[0084] The second end of the second resistor R2 is electrically connected to the first end of the first capacitor C1 and the ground end GND respectively;

[0085] The cathode of the first diode D1 is electrically connected to the second end of the first capacitor C1;

[0086] The emitter E of the PNP transistor V1 is electrically connected to the cathode of the first diode D1 and the second end of the first capacitor C1 respectively, the base B is electrically connected to the second end of the third resistor R3, and the collector C is electrically connected to the load switching sub-circuit 140;

[0087] The first end of the third resistor R3 is connected to the voltage output terminal V of the wide voltage output sub-circuit 110. out Electrical connection.

[0088] It should also be noted that the first capacitor C1 is an electrolytic capacitor (Electrolytic Capacitor), also known as an EC capacitor; the first diode D1 is a Schottky diode, also known as a hot carrier diode, which is a semiconductor diode with a low forward voltage drop and very fast switching action. When current flows through the Schottky diode, a voltage drop is generated on the Schottky diode terminal, usually between 0.15V and 0.45V.

[0089] In some embodiments, the capacitance value of the first capacitor C1 can be adjusted; when the capacitance value of the first capacitor C1 increases, the fast discharge time of the wide voltage output subcircuit 110 increases relatively; when the capacitance value of the first capacitor C1 decreases, the fast discharge time of the wide voltage output subcircuit 110 decreases relatively.

[0090] Figure 4 1 is a structural diagram of a load switching sub-circuit 140 provided in an embodiment of the present invention, including a fourth resistor R4, a fifth resistor R5, an N-channel MOS tube V2 and a discharge load R15, wherein:

[0091] The first end of the fourth resistor R4 is electrically connected to the collector C of the PNP transistor V1, and the second end is electrically connected to the gate of the N-channel MOS transistor V2;

[0092] The first end of the fifth resistor R5 is electrically connected to the collector C of the PNP transistor V1, and the second end is electrically connected to the source of the N-channel MOS transistor V2 and the ground terminal GND respectively;

[0093] The drain of the N-channel MOS transistor V2 is electrically connected to the first end of the discharge load R15;

[0094] The second end of the discharge load R15 is connected to the voltage output end V of the wide voltage output sub-circuit 110. out Electrical connection.

[0095] It should also be noted that when the input end of the load switching subcircuit 140 is at a low level, the N-channel MOS transistor V2 is turned off, and the discharge load R15 is not connected to the wide voltage output subcircuit 110. When the input end of the load switching subcircuit 140 receives a high-level signal from the voltage drop detection subcircuit 130, the gate voltage of the N-channel MOS transistor V2 is raised, so that the MOS transistor is turned on, and the discharge load R15 is connected to the wide voltage output subcircuit 110 to discharge the output capacitor; at the same time, the fifth resistor discharges the first capacitor C1 through the PNP transistor until the discharge voltage is equal to the voltage sampling point, so that the emitter voltage of the PNP transistor V1 is refreshed, and then the PNP transistor V1 is turned off again, and the voltage drop detection subcircuit 130 no longer outputs a high-level signal. At this time, the N-channel MOS transistor V2 is turned off again, and the discharge load R15 is no longer connected to the wide voltage output subcircuit 110.

[0096] In some embodiments, the N-channel MOS transistor may be replaced by an NPN transistor, wherein:

[0097] The collector of the NPN transistor is electrically connected to the second end of the fifth resistor R5 and the ground terminal GND respectively;

[0098] The base of the NPN transistor is electrically connected to the second end of the fourth resistor R4;

[0099] The emitter of the NPN transistor is electrically connected to the first end of the discharge load R15.

[0100] In some embodiments, the resistance value of the discharge load R15 can be adjusted; when the resistance value of the discharge load R15 increases, the rapid discharge speed of the wide voltage output subcircuit 110 is relatively slowed down; when the resistance value of the discharge load R15 decreases, the rapid discharge speed of the wide voltage output subcircuit 110 is relatively accelerated.

[0101] like Figure 5 FIG. 2 is a schematic diagram of the structure of a current sampling module 210 provided in an embodiment of the present invention, including a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a sixteenth resistor R16, a seventeenth resistor R17, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, and a first operational amplifier U1, wherein:

[0102] The first end of the sixth resistor R6 is connected to the negative current output terminal I of the wide voltage output sub-circuit 110. out- The second end is electrically connected to the inverting end of the first operational amplifier U1;

[0103] The first end of the seventh resistor R7 is connected to the positive current output terminal I of the wide voltage output sub-circuit 110. out+ The second end is electrically connected to the in-phase terminal of the first operational amplifier U1;

[0104] The first end of the eighth resistor R8 is electrically connected to the in-phase terminal of the first operational amplifier U1, and the second end is electrically connected to the ground terminal GND;

[0105] A first end of the second capacitor C2 is electrically connected to a first end of the eighth resistor R8, and a second end of the second capacitor C2 is electrically connected to a second end of the eighth resistor R8;

[0106] A first end of the third capacitor C3 is electrically connected to the inverting end of the first operational amplifier U1, and a second end of the third capacitor C3 is electrically connected to the non-inverting end of the first operational amplifier U1;

[0107] A first end of the ninth resistor R9 is electrically connected to the inverting end of the first operational amplifier U1, and a second end thereof is electrically connected to the output end of the first operational amplifier U1;

[0108] A first end of the fourth capacitor C4 is electrically connected to a first end of the ninth resistor R9, and a second end of the fourth capacitor C4 is electrically connected to a second end of the ninth resistor R9;

[0109] The first end of the tenth resistor R10 is electrically connected to the output end of the first operational amplifier U1, and the second end is electrically connected to the sampling voltage comparison module 220;

[0110] A first end of the fifth capacitor C5 is electrically connected to the second end of the tenth resistor R10 , and a second end of the fifth capacitor C5 is electrically connected to the ground terminal GND.

[0111] like Figure 6 FIG. 2 is a schematic diagram of the structure of a sampling voltage comparison module 220 provided in an embodiment of the present invention, including an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a sixth capacitor C6, a seventh capacitor C7, a second operational amplifier U2, and a second diode D2, wherein:

[0112] The first end of the eleventh resistor R11 is electrically connected to the preset reference voltage BUCK+12V, and the second end is electrically connected to the first end of the twelfth resistor R12;

[0113] The second end of the twelfth resistor R12 is electrically connected to the ground terminal GND;

[0114] A first end of the sixth capacitor C6 is electrically connected to the first end of the twelfth resistor R12, and a second end of the sixth capacitor C6 is electrically connected to the second end of the twelfth resistor R12;

[0115] The first end of the thirteenth resistor R13 is electrically connected to the first end of the twelfth resistor R12, and the second end is electrically connected to the in-phase terminal of the second operational amplifier U2;

[0116] The first end of the fourteenth resistor R14 is electrically connected to the second end of the tenth resistor R10, and the second end is electrically connected to the inverting end of the second operational amplifier U2 and the first end of the seventh capacitor C7 respectively;

[0117] The second end of the seventh capacitor C7 is electrically connected to the output end of the second operational amplifier U2;

[0118] The cathode of the second diode D2 is electrically connected to the output end of the second operational amplifier U2, and the anode of the second diode D2 is electrically connected to the first end of the fourth resistor R4.

[0119] like Figure 7FIG. 1 is a schematic diagram of the structure of another fast discharge circuit provided by an embodiment of the present invention, including a wide voltage output subcircuit 110, a current sampling subcircuit 120, a voltage drop detection subcircuit 130 and a load switching subcircuit 140; wherein the voltage drop detection subcircuit 130 includes a first resistor R1, a second resistor R2, a first diode D1, a first capacitor C1, a PNP transistor V1 and a third resistor R3; the load switching subcircuit 140 includes a fourth resistor R4, a fifth resistor R5, an N-channel MOS transistor V2 and a discharge load R15; the current sampling subcircuit 1 20 includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a sixteenth resistor R16, a seventeenth resistor R17, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first operational amplifier U1, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a sixth capacitor C6, a seventh capacitor C7, a second operational amplifier U2, and a second diode D2; the wide voltage output sub-circuit 110 includes an eighteenth resistor R18, an eighth capacitor C8, and a ninth capacitor C9;

[0120] The first end of the first resistor R1 is connected to the voltage output terminal V of the wide voltage output sub-circuit 110. out The first end of the PNP transistor V1 is electrically connected to the cathode of the first diode D1 and the second end of the first capacitor C1, the base B is electrically connected to the second end of the third resistor R3, and the collector C is electrically connected to the load switching sub-circuit 140; the first end of the third resistor R3 is electrically connected to the voltage output terminal V of the wide voltage output sub-circuit 110. out Electrical connection;

[0121] The first end of the fourth resistor R4 is electrically connected to the collector C of the PNP transistor V1, and the second end is electrically connected to the gate of the N-channel MOS transistor V2; the first end of the fifth resistor R5 is electrically connected to the collector C of the PNP transistor V1, and the second end is electrically connected to the source and ground GND of the N-channel MOS transistor V2 respectively; the drain of the N-channel MOS transistor V2 is electrically connected to the first end of the discharge load R15; the second end of the discharge load R15 is electrically connected to the voltage output terminal V of the wide voltage output sub-circuit 110. out Electrical connection;

[0122] The first end of the sixth resistor R6 is connected to the negative current output terminal I of the wide voltage output sub-circuit 110.out- The first end of the seventh resistor R7 is electrically connected to the current positive output terminal I of the wide voltage output sub-circuit 110, and the second end is electrically connected to the inverting terminal of the first operational amplifier U1; the first end of the seventh resistor R7 is electrically connected to the current positive output terminal I of the wide voltage output sub-circuit 110 out+ The first end of the eighth resistor R8 is electrically connected to the in-phase end of the first operational amplifier U1, and the second end is electrically connected to the ground terminal GND; the first end of the second capacitor C2 is electrically connected to the first end of the eighth resistor R8, and the second end is electrically connected to the second end of the eighth resistor R8; the first end of the third capacitor C3 is electrically connected to the inverting end of the first operational amplifier U1, and the second end is electrically connected to the in-phase end of the first operational amplifier U1; the first end of the ninth resistor R9 is electrically connected to the inverting end of the first operational amplifier U1, and the second end is electrically connected to the output end of the first operational amplifier U1; the first end of the fourth capacitor C4 is electrically connected to the first end of the ninth resistor R9, and the second end is electrically connected to the second end of the ninth resistor R9; the first end of the tenth resistor R10 is electrically connected to the output end of the first operational amplifier U1, and the second end is electrically connected to the sampling voltage comparison module 220; the first end of the fifth capacitor C5 is electrically connected to the second end of the tenth resistor R10, and the second end is electrically connected to the ground terminal GND;

[0123] The first end of the eleventh resistor R11 is electrically connected to the preset reference voltage BUCK+12V, and the second end is electrically connected to the first end of the twelfth resistor R12; the second end of the twelfth resistor R12 is electrically connected to the ground terminal GND; the first end of the sixth capacitor C6 is electrically connected to the first end of the twelfth resistor R12, and the second end is electrically connected to the second end of the twelfth resistor R12; the first end of the thirteenth resistor R13 is electrically connected to the first end of the twelfth resistor R12, and the second end is electrically connected to the in-phase end of the second operational amplifier U2; the first end of the fourteenth resistor R14 is electrically connected to the second end of the tenth resistor R10, and the second end is electrically connected to the inverting end of the second operational amplifier U2 and the first end of the seventh capacitor C7 respectively; the second end of the seventh capacitor C7 is electrically connected to the output end of the second operational amplifier U2; the cathode of the second diode D2 is electrically connected to the output end of the second operational amplifier U2, and the anode is electrically connected to the first end of the fourth resistor R4;

[0124] The first end of the eighteenth resistor R18 is connected to the first end of the eighth capacitor C8 and the current negative output terminal I out- The second end is electrically connected to the first end of the ninth capacitor C9 and the current positive output terminal I out+ The first end of the eighth capacitor C8 is electrically connected to the ground terminal GND, and the second end is electrically connected to the voltage output terminal V outThe first end of the ninth capacitor C9 is electrically connected to the ground terminal GND, and the second end is electrically connected to the voltage output terminal V out Electrical connection.

[0125] It should also be noted that if Figure 7 The structural diagram of a wide voltage output subcircuit shown is only a simplified display of the overall structure of the wide voltage output subcircuit 110 to make the embodiment of the present invention easier to understand. Among them, the eighteenth resistor R18 represents the built-in load of the wide voltage output subcircuit 110, and the eighth capacitor C8 and the ninth capacitor C9 represent the output capacitors of the wide voltage output subcircuit 110.

[0126] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A fast discharge circuit, characterized in that: It includes a wide voltage output subcircuit, a current sampling subcircuit, a voltage drop detection subcircuit and a load switching subcircuit; wherein the wide voltage output subcircuit is electrically connected to the current sampling subcircuit, the voltage drop detection subcircuit and the load switching subcircuit respectively; the current sampling subcircuit is electrically connected to the voltage drop detection subcircuit and the load switching subcircuit respectively; the voltage drop detection subcircuit is electrically connected to the load switching subcircuit; The current sampling subcircuit is used to sample the current of the wide voltage output subcircuit, and then determine the load value of the wide voltage output subcircuit, and when the load of the wide voltage output subcircuit is higher than a preset load threshold, prevent the voltage drop detection subcircuit from outputting a high level to the load switching subcircuit; The voltage drop detection subcircuit is used to detect the voltage change of the wide voltage output subcircuit, and when the voltage of the wide voltage output subcircuit drops, output a high level to the load switching subcircuit; The load switching subcircuit is used to receive the high level output of the voltage drop detection subcircuit, and then connect the preset discharge load to the wide voltage output subcircuit to achieve rapid discharge of the wide voltage output subcircuit.

2. A fast discharge circuit according to claim 1, characterized in that: The voltage drop detection subcircuit includes a first resistor, a second resistor, a first diode, a first capacitor, a PNP transistor and a third resistor, wherein: A first end of the first resistor is electrically connected to a voltage output end of the wide voltage output subcircuit, and a second end is electrically connected to an anode of the first diode and a first end of the second resistor respectively; The second end of the second resistor is electrically connected to the first end of the first capacitor and the ground end respectively; The cathode of the first diode is electrically connected to the second end of the first capacitor; The emitter of the PNP transistor is electrically connected to the cathode of the first diode and the second end of the first capacitor respectively, the base is electrically connected to the second end of the third resistor, and the collector is electrically connected to the load switching subcircuit; The first end of the third resistor is electrically connected to the voltage output end of the wide voltage output sub-circuit.

3. A fast discharge circuit according to claim 2, characterized in that: The load switching subcircuit includes a fourth resistor, a fifth resistor, an N-channel MOS tube and a discharge load, wherein: A first end of the fourth resistor is electrically connected to the collector of the PNP transistor, and a second end thereof is electrically connected to the gate of the N-channel MOS transistor; The first end of the fifth resistor is electrically connected to the collector of the PNP transistor, and the second end is electrically connected to the source and the ground of the N-channel MOS transistor respectively; The drain of the N-channel MOS tube is electrically connected to the first end of the discharge load; The second end of the discharge load is electrically connected to the voltage output end of the wide voltage output subcircuit.

4. A fast discharge circuit according to claim 3, characterized in that: The current sampling subcircuit includes a current sampling module and a sampling voltage comparison module; wherein the current sampling module is electrically connected to the wide voltage output subcircuit and the sampling voltage comparison module respectively; the sampling voltage comparison module is electrically connected to a preset reference voltage, the current sampling module, the voltage drop detection subcircuit and the load switching subcircuit respectively; The current sampling module is used to sample the current of the wide voltage output subcircuit, and then convert it into a sampled voltage and output it to the sampled voltage comparison module; The sampling voltage comparison module is used to divide the preset reference voltage to obtain a comparison voltage, and then compare it with the sampling voltage. When the sampling voltage is greater than the comparison voltage, it is considered that the load of the wide voltage output sub-circuit is higher than the preset load threshold, and then a low-level output is generated to lower the output level of the load switching sub-circuit, so as to prevent the voltage drop detection sub-circuit from outputting a high level to the load switching sub-circuit.

5. A fast discharge circuit according to claim 4, characterized in that: The current sampling module includes a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, and a first operational amplifier, wherein: A first end of the sixth resistor is electrically connected to the negative current output terminal of the wide voltage output subcircuit, and a second end thereof is electrically connected to the inverting terminal of the first operational amplifier; A first end of the seventh resistor is electrically connected to the current positive output end of the wide voltage output subcircuit, and a second end is electrically connected to the non-inverting end of the first operational amplifier; The first end of the eighth resistor is electrically connected to the in-phase terminal of the first operational amplifier, and the second end is electrically connected to the ground terminal; A first end of the second capacitor is electrically connected to a first end of the eighth resistor, and a second end of the second capacitor is electrically connected to a second end of the eighth resistor; A first end of the third capacitor is electrically connected to the inverting end of the first operational amplifier, and a second end of the third capacitor is electrically connected to the non-inverting end of the first operational amplifier; A first end of the ninth resistor is electrically connected to the inverting end of the first operational amplifier, and a second end of the ninth resistor is electrically connected to the output end of the first operational amplifier; A first end of the fourth capacitor is electrically connected to a first end of the ninth resistor, and a second end of the fourth capacitor is electrically connected to a second end of the ninth resistor; A first end of the tenth resistor is electrically connected to the output end of the first operational amplifier, and a second end of the tenth resistor is electrically connected to the sampling voltage comparison module; The first end of the fifth capacitor is electrically connected to the second end of the tenth resistor, and the second end of the fifth capacitor is electrically connected to the ground.

6. A fast discharge circuit according to claim 5, characterized in that: The sampling voltage comparison module includes an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a sixth capacitor, a seventh capacitor, a second operational amplifier, and a second diode, wherein: The first end of the eleventh resistor is electrically connected to a preset reference voltage, and the second end is electrically connected to the first end of the twelfth resistor; The second end of the twelfth resistor is electrically connected to the ground end; The first end of the sixth capacitor is electrically connected to the first end of the twelfth resistor, and the second end of the sixth capacitor is electrically connected to the second end of the twelfth resistor; The first end of the thirteenth resistor is electrically connected to the first end of the twelfth resistor, and the second end is electrically connected to the non-inverting terminal of the second operational amplifier; The first end of the fourteenth resistor is electrically connected to the second end of the tenth resistor, and the second end is electrically connected to the inverting end of the second operational amplifier and the first end of the seventh capacitor respectively; The second end of the seventh capacitor is electrically connected to the output end of the second operational amplifier; The cathode of the second diode is electrically connected to the output end of the second operational amplifier, and the anode of the second diode is electrically connected to the first end of the fourth resistor.

7. A fast discharge circuit according to claim 6, characterized in that: The N-channel MOS transistor can be replaced by an NPN transistor, wherein: The collector of the NPN transistor is electrically connected to the second end of the fifth resistor and the ground end respectively; The base of the NPN transistor is electrically connected to the second end of the fourth resistor; The emitter of the NPN transistor is electrically connected to the first end of the discharge load.

8. A fast discharge circuit according to claim 6, characterized in that: The resistance value of the discharge load can be adjusted; when the resistance value of the discharge load increases, the rapid discharge speed of the wide voltage output subcircuit is relatively slowed down; when the resistance value of the discharge load decreases, the rapid discharge speed of the wide voltage output subcircuit is relatively accelerated.

9. A fast discharge circuit according to claim 6, characterized in that: The capacitance value of the first capacitor can be adjusted; when the capacitance value of the first capacitor increases, the fast discharge time of the wide voltage output subcircuit is relatively increased; when the capacitance value of the first capacitor decreases, the fast discharge time of the wide voltage output subcircuit is relatively reduced.

10. A wide voltage output device, characterized in that: The invention comprises a fast discharge circuit as claimed in any one of claims 1 to 9.

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