阅读说明：本技术 多电源系统的电源电压监控电路 (Power supply voltage monitoring circuit of multi-power supply system ) 是由 赵勇 唐保权 白雪 彭根斋 刘有彬 于 2021-03-19 设计创作，主要内容包括：本发明公开了一种多电源系统的电源电压监控电路,包括控制与驱动网络、第一电源输出控制网络和第二电源监控网络,控制与驱动网络根据第一电源输出控制网络的反馈信号Vfb,和按键key的信号,输出驱动信号Vdr；第一电源输出控制网络根据Vdr的信号和光耦的工作状态,控制第一电源V1的输出,且输出反馈信号Vfb；第二电源监控网络实现对第二电源V2的电压监控。控制与驱动网络、第一电源输出控制网络和第二电源监控网络实现了对V2的电压监控和V1的输出控制的闭环。本发明适用于多电源系统电压监控应用,尤其适用于有正负电压的多电源系统电压监控应用,可嵌入到整机的硬件系统内、也可独立成模块使用,电路结构简单,成本低廉,响应速度快。(The invention discloses a power supply voltage monitoring circuit of a multi-power supply system, which comprises a control and drive network, a first power supply output control network and a second power supply monitoring network, wherein the control and drive network outputs a drive signal Vdr according to a feedback signal Vfb of the first power supply output control network and a signal of a key; the first power output control network controls the output of a first power V1 according to the signal of Vdr and the working state of the optical coupler, and outputs a feedback signal Vfb; the second power supply monitoring network enables voltage monitoring of the second power supply V2. The control and drive network, the first power output control network and the second power monitoring network implement a closed loop for voltage monitoring of V2 and output control of V1. The invention is suitable for monitoring the voltage of a multi-power system, in particular to the voltage of the multi-power system with positive and negative voltages, can be embedded into a hardware system of the whole machine and can also be independently used as a module, and has the advantages of simple circuit structure, low cost and high response speed.)

1. A power supply voltage monitoring circuit of a multi-power supply system is characterized in that: the power supply comprises a control and drive network, a first power output control network, a second power monitoring network, a first power supply V1, a second power supply V2 and a working power supply V3;

the control and drive network comprises a D trigger U3, a driver U5, a shaping circuit, an anti-reverse diode D2 and a Key Key, wherein the 1CLK pin of the U3 is connected with the anode of the D2 through the shaping circuit; the shaping circuit and the D2 are also connected with a working power supply V3 through a resistor R4; the negative pole of D2 is a feedback signal input terminal for inputting feedback signal Vfb, U3Key is connected to the foot, and U3's 1Q foot connects the input of driver U5, and U5's input is drive signal output for according to feedback signal Vfb, Key Key, output Vdr drive signal, specifically do:

when the Key is pressed down, triggering a Vdr driving signal to change from a low level to a high level;

the rising edge of the feedback signal Vfb changing from low level to high level triggers the Vdr driving signal to change from high level to low level;

the low level is less than or equal to 0.5V, and the high level is more than or equal to 3.5V;

the first power output control network comprises an optical coupler U2, a PMOS tube Q1 and an NMOS tube Q2;

the 5 pins of the optocoupler U2 are divided into two paths, one path is connected with the negative electrode of the D2 and used for connecting a feedback signal Vfb, the other path is connected with the G pole of the Q1, the S pole of the Q1 is connected with the input end of the V1, the D pole is connected with the output end of the V1, and the G pole of the Q1 and the input end of the V1 are connected with a resistor R2 and a capacitor C2 in parallel; a 4-pin of the optocoupler U2 is connected with a D pole of the Q2, a G pole of the Q2 is connected with a driving signal output end of the U5 and used for inputting a driving signal Vdr, and an S pole of the Q2 is grounded; a 6-pin of the optical coupler U2 is connected with a working power supply V3;

the first power output control network is configured to:

if the optocoupler U2 emits light and Vdr is at a high level, both the Q1 and the Q2 are switched on, the first power supply V1 is output through the Q1, and the feedback signal Vfb is at a low level;

if the optocoupler U2 does not emit light and Vdr is at a low level, the Q1 and the Q2 are both cut off, the first power supply V1 is not output through the Q1, and the feedback signal Vfb is at a high level;

the second power supply monitoring network is connected with a second power supply V2 and an input end of an optical coupler U2, a set voltage V4 is set to monitor V2, when the voltage value of V2 is larger than the voltage value of V4, U2 emits light, and when the voltage value of V2 is smaller than the voltage value of V4, U2 does not emit light.

2. The power supply voltage monitoring circuit of a multi power supply system according to claim 1, characterized in that: the shaping circuit comprises Schmidt input inverters U1A and U1B, the output end of U1A is connected with the 1CLK pin of U3, the input end of U1A is connected with the output end of U1B, and the input end of U1B is connected with an anti-reflection diode D2.

3. The power supply voltage monitoring circuit of a multi power supply system according to claim 1, characterized in that: the second power supply monitoring network comprises a voltage regulator tube U4, a voltage regulator diode D3, an adjustable potentiometer R10, a resistor R7 and a resistor R3, wherein the input end of the voltage regulator tube U4 is connected with V2, the adjusting end of the voltage regulator tube U4 is grounded through R10 and R7, the output end of the voltage regulator tube U4 is connected with the 3 pin of U2 through the anode of D3 and the cathode of D3, the 1 pin of the U2 is grounded through R3, the adjustable potentiometer R10 is used for setting a set voltage V4, when the voltage value of V2 is larger than the voltage value of V4, the U2 emits light, and when the voltage value of V2 is smaller than the voltage value of V4, the U2 does.

Technical Field

The present invention relates to a power supply voltage monitoring circuit, and more particularly, to a power supply voltage monitoring circuit for a multi-power system.

Background

The electronic information industry is an important industry related to national economic development, the requirements of electronic equipment on stability and reliability are higher and higher, a plurality of working power supplies and even a plurality of positive and negative voltage power supplies exist in a plurality of electronic systems, and in the multi-power-supply systems, strict requirements on the power-on and power-off time sequence of each power supply are always required. For example, in some +5V and-48V operating systems, after-48V is required to be powered down, +5V must be powered down immediately, or there will be a risk of damage to the system.

For an electronic system with multiple working power supplies with up-down power sequence requirements, a voltage monitoring method commonly used in the industry at present is realized by resistance voltage division, a comparator, a programmable device MCU and the like, and the voltage monitoring method is relatively suitable for system occasions with a plurality of positive voltage power supplies; on the other hand, the programmable device MCU has a certain response delay, and its response speed cannot be compared with a high-speed hardware circuit.

At present, for electronic systems with multiple working power supplies, especially electronic systems with positive and negative voltage power supplies, and electronic systems with power supply up and down timing requirements, there is no better power supply voltage monitoring method, and the requirement of high reliability of the electronic systems cannot be met. The supplement of new technology is urgently needed.

Disclosure of Invention

The present invention is directed to provide a power supply voltage monitoring circuit for a multi-power system, which can effectively monitor a power supply voltage, and has a simple circuit structure, a low cost, and a fast response speed.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a power supply voltage monitoring circuit of a multi-power supply system comprises a control and drive network, a first power supply output control network, a second power supply monitoring network, a first power supply V1, a second power supply V2 and a working power supply V3;

the control and drive network comprises a D trigger U3, a driver U5, a shaping circuit, an anti-reverse diode D2 and a Key Key, wherein the 1CLK pin of the U3 is connected with the anode of the D2 through the shaping circuit; the shaping circuit and the D2 are also connected with a working power supply V3 through a resistor R4; the negative pole of D2 is a feedback signal input terminal for inputting feedback signal Vfb, U3Key is connected to the foot, and U3's 1Q foot connects the input of driver U5, and U5's input is drive signal output for according to feedback signal Vfb, Key Key, output Vdr drive signal, specifically do:

when the Key is pressed down, triggering a Vdr driving signal to change from a low level to a high level;

the rising edge of the feedback signal Vfb changing from low level to high level triggers the Vdr driving signal to change from high level to low level;

the low level is less than or equal to 0.5V, and the high level is more than or equal to 3.5V;

the first power output control network comprises an optical coupler U2, a PMOS tube Q1 and an NMOS tube Q2;

the 5 pins of the optocoupler U2 are divided into two paths, one path is connected with the negative electrode of the D2 and used for connecting a feedback signal Vfb, the other path is connected with the G pole of the Q1, the S pole of the Q1 is connected with the input end of the V1, the D pole is connected with the output end of the V1, and the G pole of the Q1 and the input end of the V1 are connected with a resistor R2 and a capacitor C2 in parallel; a 4-pin of the optocoupler U2 is connected with a D pole of the Q2, a G pole of the Q2 is connected with a driving signal output end of the U5 and used for inputting a driving signal Vdr, and an S pole of the Q2 is grounded; a 6-pin of the optical coupler U2 is connected with a working power supply V3;

the first power output control network is configured to:

if the optocoupler U2 emits light and Vdr is at a high level, both the Q1 and the Q2 are switched on, the first power supply V1 is output through the Q1, and the feedback signal Vfb is at a low level;

if the optocoupler U2 does not emit light and Vdr is at a low level, the Q1 and the Q2 are both cut off, the first power supply V1 is not output through the Q1, and the feedback signal Vfb is at a high level;

the second power supply monitoring network is connected with a second power supply V2 and an input end of an optical coupler U2, a set voltage V4 is set to monitor V2, when the voltage value of V2 is larger than the voltage value of V4, U2 emits light, and when the voltage value of V2 is smaller than the voltage value of V4, U2 does not emit light.

Preferably, the method comprises the following steps: the shaping circuit comprises Schmidt input inverters U1A and U1B, the output end of U1A is connected with the 1CLK pin of U3, the input end of U1A is connected with the output end of U1B, and the input end of U1B is connected with an anti-reflection diode D2.

Preferably, the method comprises the following steps: the second power supply monitoring network comprises a voltage regulator tube U4, a voltage regulator diode D3, an adjustable potentiometer R10, a resistor R7 and a resistor R3, wherein the input end of the voltage regulator tube U4 is connected with V2, the adjusting end of the voltage regulator tube U4 is grounded through R10 and R7, the output end of the voltage regulator tube U4 is connected with the 3 pin of U2 through the anode of D3 and the cathode of D3, the 1 pin of the U2 is grounded through R3, the adjustable potentiometer R10 is used for setting a set voltage V4, when the voltage value of V2 is larger than the voltage value of V4, the U2 emits light, and when the voltage value of V2 is smaller than the voltage value of V4, the U2 does.

Compared with the prior art, the invention has the advantages that:

(1) the control and drive network of the present invention: when Vfb changes from low to high, if Key is not pressed, the output Vdr is low and locked, and if Key is pressed, the output Vdr is high and locked. The locking function of the Vdr signal can prevent the output of the first power supply V1 from being frequently controlled due to the fluctuation of the monitored second power supply V2 around the set voltage V4. The diode D2 is an anti-reverse diode that prevents the feedback signal Vfb from going higher than the operating supply V3. U1A and U1B are schmitt input inverters for shaping the slower feedback signal Vfb and outputting a high speed signal with steep edges. The driver U5 provides a strong driving capability for the output signal Vdr.

(2) The first power output control network is for: when the optocoupler U2 emits light, Vdr is at a high level, Q2 and Q1 are both switched on, V1 is output through Q1, and Vfb is at a low level; when the optocoupler U2 does not emit light, and Vdr is at a low level, Q2 and Q1 are both cut off, V1 is not output through Q1, and Vfb is at a high level. In order to improve the response speed, a high-speed photoelectric coupler, a high-speed PMOS tube Q1 and a high-speed NMOS tube Q2 are selected.

(3) A second power supply monitoring network: the voltage monitoring of the V2 is realized, and when the voltage of the V2 is reduced to the set voltage V4, the working state of the photoelectric coupler U2 is changed, so that the feedback signal Vfb is changed. When the voltage of V2 is in the normal range and Vdr is at high level, U2 works in a light-emitting state, and Vfb is at low level; when the voltage of V2 is reduced to the set voltage V4, U2 operates in the non-light emitting state, and Vfb becomes high level and close to V1. In the invention, V2 can be a positive voltage power supply or a negative voltage power supply, and the voltage value can be a value in a larger range; since a drop in V2 to V4 triggers a Vfb change, the voltage value of V4 is the monitoring voltage point, which is set by the adjustable potentiometer R10; v2 and V1 can be isolated non-common ground power supplies or common ground power supplies.

In summary, the control and driving network, the first power output control network and the second power monitoring network cooperate to realize a closed loop of voltage monitoring of the second power supply V2 and output control of the first power supply V1. The circuit has the advantages of simple structure, low cost, wide settable monitoring voltage range and high response speed. The voltage monitoring device is suitable for voltage monitoring application of a multi-power-supply system, particularly for voltage monitoring application of a multi-power-supply system with positive and negative voltages, can be embedded into a hardware system of a complete machine for use, and can also be independently formed into a module for use.

Drawings

FIG. 1 is a circuit diagram of the present invention.

Detailed Description

The invention will be further explained with reference to the drawings.

Example 1: referring to fig. 1, a power supply voltage monitoring circuit of a multi-power supply system is characterized in that: the power supply comprises a control and drive network, a first power output control network, a second power monitoring network, a first power supply V1, a second power supply V2 and a working power supply V3;

the control and drive network comprises a D trigger U3, a driver U5, a shaping circuit, an anti-reverse diode D2 and a Key Key, wherein the 1CLK pin of the U3 is connected with the anode of the D2 through the shaping circuit; the shaping circuit and the D2 are also connected with a working power supply V3 through a resistor R4; the negative pole of D2 is a feedback signal input terminal for inputting feedback signal Vfb, U3Key is connected to the foot, and U3's 1Q foot connects the input of driver U5, and U5's input is drive signal output for according to feedback signal Vfb, Key Key, output Vdr drive signal, specifically do:

when the Key is pressed down, triggering a Vdr driving signal to change from a low level to a high level;

the rising edge of the feedback signal Vfb changing from low level to high level triggers the Vdr driving signal to change from high level to low level;

the low level is less than or equal to 0.5V, and the high level is more than or equal to 3.5V;

the first power output control network comprises an optical coupler U2, a PMOS tube Q1 and an NMOS tube Q2;

the 5 pins of the optocoupler U2 are divided into two paths, one path is connected with the negative electrode of the D2 and used for connecting a feedback signal Vfb, the other path is connected with the G pole of the Q1, the S pole of the Q1 is connected with the input end of the V1, the D pole is connected with the output end of the V1, and the G pole of the Q1 and the input end of the V1 are connected with a resistor R2 and a capacitor C2 in parallel; a 4-pin of the optocoupler U2 is connected with a D pole of the Q2, a G pole of the Q2 is connected with a driving signal output end of the U5 and used for inputting a driving signal Vdr, and an S pole of the Q2 is grounded; a 6-pin of the optical coupler U2 is connected with a working power supply V3;

the first power output control network is configured to:

if the optocoupler U2 emits light and Vdr is at a high level, both the Q1 and the Q2 are switched on, the first power supply V1 is output through the Q1, and the feedback signal Vfb is at a low level;

if the optocoupler U2 does not emit light and Vdr is at a low level, the Q1 and the Q2 are both cut off, the first power supply V1 is not output through the Q1, and the feedback signal Vfb is at a high level;

the second power supply monitoring network is connected with a second power supply V2 and an input end of an optical coupler U2, a set voltage V4 is set to monitor V2, when the voltage value of V2 is larger than the voltage value of V4, U2 emits light, and when the voltage value of V2 is smaller than the voltage value of V4, U2 does not emit light.

In this embodiment, the shaping circuit includes schmitt input inverters U1A and U1B, the output terminal of U1A is connected to the 1CLK pin of U3, the input terminal of U1A is connected to the output terminal of U1B, and the input terminal of U1B is connected to the anti-reflection diode D2. The second power supply monitoring network comprises a voltage regulator tube U4, a voltage regulator diode D3, an adjustable potentiometer R10, a resistor R7 and a resistor R3, wherein the input end of the voltage regulator tube U4 is connected with V2, the adjusting end of the voltage regulator tube U4 is grounded through R10 and R7, the output end of the voltage regulator tube U4 is connected with the 3 pin of U2 through the anode of D3 and the cathode of D3, the 1 pin of the U2 is grounded through R3, the adjustable potentiometer R10 is used for setting a set voltage V4, when the voltage value of V2 is larger than the voltage value of V4, the U2 emits light, and when the voltage value of V2 is smaller than the voltage value of V4, the U2 does.

Example 2: referring to fig. 1, in order to better illustrate the effect of the present invention, we further define on the basis of example 1. We set the first power supply V1=10V, the second power supply V2= -48V, the operating power supply V3=5V, and the setting voltage V4= -40V.

Regarding the control and driving network, the control and driving network not only comprises a D flip-flop U3, a driver U5, a shaping circuit, an anti-reverse diode D2 and a Key, but also comprises a resistor R4, a resistor R9, a resistor R12, a resistor R14, a capacitor C4, a capacitor C5, a capacitor C6 and a capacitor C7. The D flip-flop U3 adopts a chip 74LS74, and the driver U5 adopts a chip MAX4427 MJA. The specific connection is as follows:

of D flip-flop U3The pin is divided into two paths, one path is connected with 5V voltage through a resistor R9, and the other path is grounded through a capacitor C4.

The pin 1D of the D flip-flop U3 is connected to ground through a resistor R12.

The 1CLK pin of the D trigger U3 is connected to the output end of the inverter U1A, the input end of the inverter U1A is connected to the output end of the inverter U1B, the input end of the inverter U1B is also divided into two paths, one path is connected with 5V voltage through a resistor R4, the other path is connected with the anode of a diode D2, and the cathode of the diode D2 is connected with a feedback signal Vfb.

Of D flip-flop U3The pin is divided into three paths, one path is connected with 5V voltage through a resistor R14, the other path is grounded through a key, and the other path is grounded through a capacitor C7.

1 of D flip-flop U3The feet float.

The GND pin of D flip-flop U3 is connected to ground.

The 1Q pin of D flip-flop U3 is connected to the INA pin of driver U5.

The VCC pin of the D flip-flop U3 is connected to 5V voltage and is grounded via the capacitor C5.

The INB pin of driver U5 is floating, the OUTA pin of driver U5 is connected to drive signal Vdr, the OUTB pin of driver U5 is floating, and the GND pin of driver U5 is grounded.

In the control and drive network, a resistor R4, a resistor R9, a resistor R12, a resistor R14, a capacitor C4, a capacitor C5, a capacitor C6 and a capacitor C7. The capacitors C4 and C7 serve as input signal bypass capacitors, and the capacitors C5 and C6 serve as power supply decoupling capacitors for U3 and U5, respectively.

With respect to the first power output control network: besides the optocoupler U2, the PMOS tube Q1 and the NMOS tube Q2, the optocoupler further comprises a light emitting diode D1, a resistor R1, a resistor R2, a resistor R11, a resistor R13, a capacitor C2 and a capacitor C3. The optocoupler U2 adopts a TLP719 chip, and the optocoupler U2, the PMOS transistor Q1, and the NMOS transistor Q2 are connected in the same manner as in embodiment 1, and the specific connection manner for the added capacitor, the added resistor, and the added light emitting diode is as follows:

the resistor R2 and the capacitor C2 form an RC parallel circuit and are connected between the input end of the first power supply V1 and the G end of the Q1.

The D pole of Q1 is connected to the anode of LED D1 and the cathode of LED D1 via resistor R1.

The resistor R2 and the capacitor C2 form an RC parallel circuit for filtering, the light emitting diode D1 is positioned at the pole Q1D, and if the V1 does not output light, the light emitting diode does not emit light, so that the light emitting diode can provide instructions for the output of the first power supply V1.

The resistor R11 and the resistor R13 are both connected to the G pole of the Q1, the other end of the resistor R11 is connected to the ground, the other end of the resistor R13 is connected to the ground, one end of the C3 is connected to the pin 6 of the U2, and the other end of the C3 is connected to the ground. The resistors R11 and R13 form a gate-level driving circuit of Q1, and the capacitor C3 is a decoupling capacitor of U2.

With respect to the second power supply monitoring network: the voltage-stabilizing diode comprises a voltage-stabilizing tube U4, a voltage-stabilizing diode D3, an adjustable potentiometer R10, a resistor R7 and a resistor R3, wherein the input end of the voltage-stabilizing tube U4 is connected with V2, the adjusting end is grounded through R10 and R7, the output end is connected with a pin 3 of U2 through the anode of D3 and the cathode of D3, a pin 1 of U2 is grounded through R3, the adjustable potentiometer R10 is used for setting a set voltage V4, when the voltage value of V2 is larger than the voltage value of V4, the optocoupler U2 emits light, and when the voltage value of V2 is smaller than the voltage value of V4, the optocoupler U2 does not emit light.

The working process of the invention is as follows:

(1) adjusting a set voltage V4= -40V, turning on a first power supply V1=10V, a second power supply V2= -48V and an operating power supply V3=5V in the circuit, and operating an optical coupler U2 in a light-emitting state at the moment;

(2) pressing a key button to change the Vdr signal from low level to high level, and opening the NMOS tube Q2, namely conducting; because the optocoupler U2 works in a light-emitting state, the PMOS tube Q1 is turned on, the Vfb signal is low, the first power supply V1 outputs normally, and the light-emitting diode D1 emits light;

(3) if the second power supply V2 is turned off or the second power supply V2 is reduced from-48V to-40V, the optocoupler U2 is switched from a light-emitting state to a non-light-emitting state, the optocoupler is not conducted, the Vfb signal is increased, and the D trigger U3 is triggered to enable the Vdr signal to be reduced;

(4) when the Vdr signal becomes low, the NMOS transistor Q2 is turned off, the PMOS transistor Q1 is turned off, the output of the first power supply V1 is turned off, and the light emitting diode D1 does not emit light;

(5) when the second power supply V2 returns to-48V again, the key button needs to be manually pressed to change the Vdr signal to high level, so that the first power supply V1 can be output again.

The circuit of the invention has simple structure, low cost, wide range of settable monitoring voltage and high response speed. On the basis of embodiment 2, for the embodiment V1=10V, V2= -48V, the settable monitoring voltage range V4= -47.5V-5V, and the response speed can reach a microsecond level.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.