Delay pressure maintaining device and method and power measuring instrument

Abstract

The invention belongs to the technical field of electronic power technologies, and particularly relates to a delay voltage maintaining device and method and a power measuring instrument, and the device comprises a one-way conduction circuit which is connected in series between the output end of a DC power conversion circuit and a load power supply end, and the one-way conduction circuit is configured to allow a current to flow from the DC power conversion circuit to the load power supply end, the reverse current from the load power supply end to the direct-current power conversion circuit is cut off; the delay voltage stabilizing circuit is connected between the load power supply end and the grounding end; therefore, when the power supply is normal, the time-delay voltage-stabilizing circuit can be charged through the one-way conduction circuit, when the output voltage of the power supply drops instantaneously, the one-way conduction circuit automatically cuts off and cuts off a disturbance source due to reverse voltage difference, and meanwhile, the time-delay voltage-stabilizing circuit discharges to maintain the voltage at the load end.

Description

Technical Field

[0001] This application relates to the field of electronic power technology, and in particular to a time-delayed voltage holding device, method, and power measuring instrument. Background Technology

[0002] In existing power supply circuit designs, to ensure the load operates normally under various conditions, a built-in fixed battery is typically used as the energy source, coupled with mature topologies such as Buck converters, Boost converters, or LDO linear regulators to provide a continuous and stable voltage output. This traditional power supply architecture performs well in terms of voltage stability and is widely used in various electronic products.

[0003] However, as electronic devices increasingly move towards miniaturization, lower cost, and greater independence, the limitations of existing technologies are becoming increasingly apparent. When a circuit initiates a high-power load, such as when a power measurement instrument is acquiring signals, it often causes a sudden and significant drop in input voltage. To cope with these millisecond-level power fluctuations, existing solutions have to rely on large-capacity backup batteries or expensive independent energy storage modules to maintain power. This not only significantly increases the hardware cost and size of the product and enhances the complexity of circuit design, but also introduces subsequent issues such as battery aging and maintenance. For devices lacking independent backup power, fluctuations in external input voltage can easily lead to the collapse of the power supply to the back-end circuitry, making it difficult to meet the design requirements of low cost and high reliability under complex operating conditions.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] In view of at least one of the above technical problems, this application provides a time-delay voltage holding device, method and power measuring instrument, which can solve the technical problem that the load power supply voltage collapses when the output voltage of the DC power conversion circuit drops momentarily, resulting in abnormal function of the subsequent circuit.

[0006] In a first aspect, a time-delayed voltage holding device is provided, the device being disposed between the output terminal of a DC power conversion circuit and the load power supply terminal, the device comprising: A unidirectional conduction circuit is connected in series between the output terminal of the DC power conversion circuit and the load power supply terminal. The unidirectional conduction circuit is configured to allow current to flow from the DC power conversion circuit to the load power supply terminal and to block reverse current from the load power supply terminal to the DC power conversion circuit. A time-delay voltage regulator circuit is connected between the load power supply terminal and the ground terminal. When the DC power conversion circuit outputs a normal voltage, it charges the delay regulator circuit through a unidirectional conduction circuit. When the output voltage of the DC power conversion circuit experiences a momentary drop, the unidirectional conduction circuit is cut off, and the delay regulator circuit discharges to the load power supply terminal to maintain the voltage level at the load power supply terminal.

[0007] In some possible implementations, the unidirectional conduction circuit includes at least one conducting element, the first end of which is connected to the output of the DC power conversion circuit, and the second end of which is connected to both the time-delay voltage regulator circuit and the load power supply terminal.

[0008] In some possible implementations, there are two conducting elements connected in parallel. One conducting element is a third diode, and the other is a fourth diode. The positive terminals of the third and fourth diodes are connected to the output terminal of the DC power conversion circuit, and the negative terminals of the third and fourth diodes are connected to the delay voltage regulator circuit and the load power supply terminal.

[0009] In some possible implementations, the time-delay voltage regulator circuit includes an energy storage voltage regulator unit and a discharge protection unit. The first terminal of the energy storage voltage regulator unit is connected to the load power supply terminal, the first terminal of the discharge protection unit is connected to the second terminal of the energy storage voltage regulator unit, and the second terminal of the discharge protection unit is connected to the output terminal of the DC power conversion circuit.

[0010] In some possible implementations, the energy storage voltage regulator unit has multiple capacitors connected in parallel. The first terminals of the multiple capacitors are respectively connected to the load power supply terminal and the first terminal of the discharge protection unit, and the second terminals of the multiple capacitors are grounded together.

[0011] In some possible implementations, the discharge protection unit includes a fifth transistor and a bias resistor. The base of the fifth transistor is connected to the output terminal of the DC power conversion circuit through the bias resistor. The collector of the fifth transistor is connected to the second terminal of the energy storage voltage regulator unit. The emitter of the fifth transistor is grounded.

[0012] In some possible implementations, the fifth transistor is configured such that when the external power supply is reversed, causing the output voltage of the DC power conversion circuit to be zero, the base voltage of the fifth transistor is less than the emitter voltage of the fifth transistor, causing the fifth transistor to conduct, thereby releasing the charge in the energy storage and voltage regulation unit.

[0013] In some possible implementations, the fifth transistor is configured such that when the load connected to the load power supply terminal starts up, the voltage at the output terminal of the DC power conversion circuit drops, the base voltage of the fifth transistor is less than the emitter voltage of the fifth transistor, causing the fifth transistor to conduct, thereby releasing the charge in the energy storage voltage regulator unit.

[0014] Secondly, a power measuring instrument is provided, comprising: A DC power conversion circuit, configured to receive an external power supply voltage; A time-delayed voltage holding device is connected to a DC power conversion circuit. The load circuit includes a power measurement circuit, which is connected to the load power supply terminal. The time-delay voltage holding device is configured to clamp the input voltage of the power measurement circuit within a preset operating voltage range during the period when the power measurement circuit is instantaneously activated, causing a momentary drop in the voltage at the output of the DC power conversion circuit.

[0015] Thirdly, a time-delayed voltage holding method is provided for use in power measuring instruments. The method includes: When the DC power conversion circuit outputs a normal voltage, the delay voltage regulator circuit is charged and stored through the unidirectional conduction circuit. When the load circuit starts up, causing a momentary drop in the output voltage of the DC power conversion circuit, which is lower than the voltage at the load power supply terminal, the unidirectional conduction circuit is cut off to isolate the output terminal of the DC power conversion circuit. The time-delay voltage regulator circuit releases the stored electrical energy to the load power supply terminal, clamping the voltage at the load power supply terminal within the preset operating voltage range until the output voltage of the DC power conversion circuit returns to normal.

[0016] This application provides a time-delay voltage holding device, method, and power measuring instrument. By setting a unidirectional conduction circuit in series between the output terminal of the DC power conversion circuit and the load power supply terminal, and setting a time-delay voltage regulator circuit connected between the load power supply terminal and the ground terminal, the time-delay voltage regulator circuit can be charged through the unidirectional conduction circuit when the power supply is normal. When the power supply output voltage drops momentarily, the unidirectional conduction circuit automatically cuts off due to the reverse voltage difference, cutting off the disturbance source. At the same time, the time-delay voltage regulator circuit discharges to maintain the load terminal voltage, thereby solving the technical problem in the prior art that the power supply of the downstream circuit collapses and functions abnormally due to the instantaneous drop in input voltage. It achieves the technical effects of no need for backup batteries, low cost, high response speed, strong voltage clamping capability, and good engineering compatibility.

[0017] The present application will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the power measuring instrument provided in the embodiments of this application; Figure 2 yes Figure 1 Circuit diagram of the time-delayed pressure holding device in the middle; Figure 3 It is a waveform diagram of the external power supply voltage. Figure 4 This is the output waveform diagram of the output voltage of the DC power conversion circuit; Figure 5 It is the voltage waveform at the load power supply end after adding a time-delay voltage holding device; In the picture: 100. DC power conversion circuit; 200. Delayed voltage holding device; 210. Load power supply terminal; 220. Unidirectional conduction circuit; 230. Delayed voltage regulation circuit; 221, conducting element; D3, third diode; D4, fourth diode; 231, Energy storage voltage regulator unit; 232, Discharge protection unit; Q5, Fifth transistor; R54, Bias resistor; 300. Load circuit; 310. Power measurement circuit; Detailed Implementation

[0020] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0021] In electronic devices such as power measurement instruments that are sensitive to power supply continuity, DC power conversion circuits (such as DC-DC converters) often experience a momentary drop in input voltage due to sudden load initiation when driving highly dynamic loads (such as alternating acquisition of short-circuit current Isc and maximum power point current Imp), causing the output voltage to drop by milliseconds.

[0022] Figure 3 It is a waveform diagram of the external power supply voltage. Figure 4 This is the output waveform diagram of the output voltage of the DC power conversion circuit. For example... Figure 3 As shown, with an external power supply voltage of 20V, the power measurement circuit starts, using the yellow line as a reference line. The external power supply voltage will momentarily drop to near 0V. Figure 4As shown, when the external 20V power supply outputs a stable 12V (denoted as VS) through the DC power conversion circuit, the power measurement circuit can cause the output voltage VS of the DC power conversion circuit to drop sharply from 12.0V to 5.28V at startup, resulting in system reset, sampling interruption, or false triggering. Traditional solutions rely on backup batteries for delayed voltage maintenance, which suffers from high cost, large size, low integration, and the need for additional management circuitry. Some capacitor energy storage solutions lack effective isolation and clamping mechanisms, making it easy for stored energy to discharge back to the power supply side, exacerbating voltage collapse and failing to achieve accurate and controllable voltage maintenance.

[0023] In this regard, such as Figure 1 and Figure 2 As shown, one embodiment provides a power measuring instrument, including: a DC power conversion circuit 100, a time-delay voltage holding device 200, and a load circuit 300.

[0024] The DC power conversion circuit 100 is configured to receive an external power supply voltage; the time-delay voltage holding device 200 is connected to the DC power conversion circuit 100; the load circuit 300 includes a power measurement circuit 310, which is connected to the load power supply terminal 210; the time-delay voltage holding device 200 is configured to clamp the input voltage of the power measurement circuit 310 within a preset operating voltage range during the period when the power measurement circuit 310 is instantaneously activated, causing a momentary drop in the voltage at the output terminal of the DC power conversion circuit 100.

[0025] The DC-DC power conversion circuit 100 is a wide-input-range DC-DC step-down converter, with its input terminals adapted to 12 to 36 V external DC power supplies, and its output terminals providing a stable nominal 12 V voltage. It should be noted that the output voltage of the DC-DC power conversion circuit 100 can be... Figure 1 VS in the middle.

[0026] The time-delay voltage holding device 200 is connected between the DC power conversion circuit 100 and the load circuit 300. For example... Figure 1 and Figure 2 As shown, the time-delay voltage holding device 200 includes a unidirectional conduction circuit 220 and a time-delay voltage stabilizing circuit 230.

[0027] A unidirectional conduction circuit 220 is connected in series between the output terminal of the DC power conversion circuit 100 and the load power supply terminal 210; a delay voltage regulator circuit 230 is connected between the load power supply terminal 210 and the ground terminal. It is worth noting that the load power supply terminal 210 is used to connect to the load circuit 300. That is, the unidirectional conduction circuit 220 is connected between the output terminal of the DC power conversion circuit 100 and the load circuit 300.

[0028] The unidirectional conduction circuit 220 is configured to allow current to flow from the DC-DC power conversion circuit 100 to the load power supply terminal 210, and to block reverse current from the load power supply terminal 210 to the DC-DC power conversion circuit 100. Under normal operating conditions, the potential of the DC-DC power conversion circuit 100 is higher than that of the load power supply terminal 210, forward biasing the unidirectional conduction element 221 and forming a low-resistance path. When the output voltage of the DC-DC power conversion circuit 100 momentarily drops due to a sudden load change, the load power supply terminal 210 maintains its voltage due to the delay regulator circuit 230, causing the unidirectional conduction circuit 220 to enter the reverse cutoff region, exhibiting a high-resistance state. This physically isolates the DC-DC power conversion circuit 100 from the load circuit 300, preventing charge from the delay regulator circuit 230 from flowing back to the faulty power supply and avoiding further sags in the output voltage of the DC-DC power conversion circuit 100. This cutoff process requires no external control signal and is entirely triggered spontaneously by the voltage difference, with a response time in the nanosecond range, far faster than MCU detection plus software intervention solutions.

[0029] When the DC power conversion circuit 100 is outputting a normal voltage, it charges the delay regulator circuit 230 through the unidirectional conduction circuit 220. It can be understood that when the load circuit 300 is not running, and the DC power conversion circuit 100 receives an external power supply voltage, the output voltage of the DC power conversion circuit 100 flows through the unidirectional conduction circuit 220 and charges the delay regulator circuit 230. At this time, the delay regulator circuit 230 is in an energy storage state and does not participate in power supply.

[0030] When the output voltage of the DC power conversion circuit 100 experiences a momentary drop, the unidirectional conduction circuit 220 is in the off state, and the time-delay voltage regulator circuit 230 discharges to the load power supply terminal 210 to maintain the voltage level of the load power supply terminal 210. It can be understood that when the output voltage of the DC power conversion circuit 100 drops rapidly due to the start-up of the load circuit 300, and the voltage of the load power supply terminal 210 becomes higher than the voltage of the DC power conversion circuit 100, the unidirectional conduction circuit 220 is cut off due to the voltage difference, thereby disconnecting the connection between the DC power conversion circuit 100 and the load circuit 300. At this time, the charge stored in the time-delay voltage regulator circuit 230 is released to the load power supply terminal 210, thereby clamping the voltage of the load power supply terminal 210 within a preset safe range.

[0031] The time-delay voltage holding device 200 provided in this embodiment has a unidirectional conduction circuit 220 connected in series between the output terminal of the DC power conversion circuit 100 and the load power supply terminal 210, and a time-delay voltage regulator circuit 230 connected between the load power supply terminal 210 and the ground terminal. This allows the time-delay voltage regulator circuit 230 to be charged through the unidirectional conduction circuit 220 when the power supply output voltage drops momentarily. When the power supply output voltage drops momentarily, the unidirectional conduction circuit 220 automatically cuts off due to the reverse voltage difference, cutting off the disturbance source. At the same time, the time-delay voltage regulator circuit 230 discharges to maintain the load terminal voltage. This solves the technical problem in the prior art where the power supply of the downstream circuit collapses and functions abnormally due to the instantaneous drop in input voltage. It achieves the technical effects of no need for a backup battery, low cost, high response speed, strong voltage clamping capability, and good engineering compatibility.

[0032] like Figure 1 and Figure 2 As shown, in some embodiments, the unidirectional conduction circuit 220 includes at least one conducting element 221. The first end of the conducting element 221 is connected to the output end of the DC power conversion circuit 100, and the second end of the conducting element 221 is connected to the delay voltage regulator circuit 230 and the load power supply terminal 210.

[0033] It is understandable that the conducting element 221 can be a diode or a MOSFET in conjunction with control logic, etc.

[0034] When the DC power conversion circuit 100 is operating at normal output voltage, the conducting element 221 allows current to flow from the DC power conversion circuit 100 to the time-delay voltage regulator circuit 230 for charging. When the load circuit 300 starts, the output voltage of the DC power conversion circuit 100 experiences a momentary drop, causing the output voltage of the DC power conversion circuit 100 to be lower than the voltage at the load power supply terminal 210. The conducting element 221 then enters the cut-off state, blocking the current return flow, thereby achieving electrical isolation of the DC power conversion circuit 100.

[0035] like Figure 1 and Figure 2 As shown, in some embodiments, there are two conducting elements 221 connected in parallel. One conducting element 221 is a third diode D3, and the other conducting element 221 is a fourth diode D4. The positive terminals of the third diode D3 and the fourth diode D4 are connected to the output terminal of the DC power conversion circuit 100, and the negative terminals of the third diode D3 and the fourth diode D4 are connected to the delay voltage regulator circuit 230 and the load power supply terminal 210.

[0036] Specifically, the anodes of the third diode D3 and the fourth diode D4 are connected to the output of the DC power conversion circuit 100, while the cathodes of the third diode D3 and the fourth diode D4 are connected to the time-delay voltage regulator circuit 230 and the load power supply terminal 210, forming a parallel unidirectional conduction path. In terms of component selection, Schottky diodes are preferred, such as the SS14 Schottky barrier diode. Its typical forward voltage drop is approximately 0.45V-0.55V, far lower than the 0.7V of ordinary silicon diodes, effectively reducing energy loss under normal operating conditions. Simultaneously, this type of diode has fast recovery characteristics, with a reverse recovery time of less than 10ns, ensuring rapid response during voltage transients and achieving millisecond-level power isolation.

[0037] By connecting the third diode D3 and the fourth diode D4 in parallel, with the positive terminals of both diodes connected to the output of the DC power conversion circuit 100 and the negative terminals of both diodes connected to the time-delay voltage regulator circuit 230 and the load power supply terminal 210, the input current is shunted to the two diodes when the device is operating normally, reducing the thermal load on individual diodes and improving the long-term reliability of the product. When the device is operating in a momentary power failure state, the two diodes share the reverse withstand voltage, enhancing the circuit's anti-interference capability. Furthermore, the parallel diode design also provides redundancy; if one diode experiences an open-circuit fault, the other diode can still maintain basic unidirectional conduction, improving the fault tolerance of the entire time-delay voltage regulator 200.

[0038] For example, in a momentary power failure scenario, when the output voltage of the DC power conversion circuit 100 drops rapidly due to load startup, the potential drops slowly because the negative terminals of the third diode D3 and the fourth diode D4 are connected to the delay voltage regulator circuit 230. Soon, the negative terminal potential of the diodes will be higher than the positive terminal potential. At this time, both diodes will enter the reverse cutoff state simultaneously, cutting off the connection path between the DC power conversion circuit 100 and the load circuit 300, and ensuring that the charge stored in the delay voltage regulator circuit 230 can maintain a stable voltage output.

[0039] like Figure 1 and Figure 2 As shown, in some embodiments, the delay voltage regulator circuit 230 includes an energy storage voltage regulator unit 231 and a discharge protection unit 232. The first end of the energy storage voltage regulator unit 231 is connected to the load power supply terminal 210, the first end of the discharge protection unit 232 is connected to the second end of the energy storage voltage regulator unit 231, and the second end of the discharge protection unit 232 is connected to the output terminal of the DC power conversion circuit 100.

[0040] The energy storage and voltage regulation unit 231 refers to a circuit capable of storing and releasing electrical energy. The first terminal of the energy storage and voltage regulation unit 231 is connected to the load power supply terminal 210, used to receive charging energy or release electrical energy to the load circuit 300. For example, the energy storage and voltage regulation unit 231 stores electrical energy under normal power supply conditions and releases electrical energy during momentary power outages to maintain the supply voltage of the load circuit 300.

[0041] The discharge protection unit 232 refers to the circuit that controls the release of electrical energy by the energy storage and voltage regulation unit 231. The first terminal of the discharge protection unit 232 is connected to the second terminal of the energy storage and voltage regulation unit 231, forming a charge discharge path. The second terminal of the discharge protection unit 232 is connected to the output terminal of the DC-DC power conversion circuit 100, and is used to respond to the voltage state of the output terminal of the DC-DC power conversion circuit 100 and control the discharge action accordingly. For example, by monitoring the voltage state of the output terminal of the DC-DC power conversion circuit 100, the charging and discharging behavior of the energy storage unit is controlled, ensuring both energy storage efficiency during normal operation and safe discharge under abnormal conditions.

[0042] Furthermore, the discharge protection unit 232 can also prevent users from quickly and accidentally connecting the positive and negative terminals of an external power supply, which could damage other circuits. It is understood that this device requires connection to and is powered by an external power supply. For example, if the user connects the external power supply incorrectly, the output voltage of the DC power conversion circuit 100 will be 0. At this time, the discharge protection unit 232 will conduct, causing the energy storage and voltage regulation unit 231 to release electrical energy.

[0043] For example, when the external power supply is normal and the load circuit 300 is not started, the DC power conversion circuit 100 outputs a stable voltage, the energy storage and voltage regulation unit 231 charges, and the discharge protection unit 232 is in the off state. When the load circuit 300 starts, causing a sharp drop in the output voltage of the DC power conversion circuit 100, the unidirectional conduction circuit 220 automatically turns off, the auxiliary protection unit turns on due to the drop in the output voltage of the DC power conversion circuit 100, and the energy storage and voltage regulation unit 231 begins to supply power to the load circuit 300. When the polarity of the external power supply is accidentally reversed, the discharge protection unit 232 immediately turns on, providing a low-impedance discharge path for the energy storage and voltage regulation unit 231, preventing high voltage reverse surges from damaging other circuit components.

[0044] Thus, the time-delay voltage regulator circuit 230 can achieve the dual functions of energy storage and protection, ensuring the continuity of power supply during momentary power outages and improving the safety and reliability of the device.

[0045] like Figure 1 and Figure 2As shown, in some embodiments, the energy storage voltage regulator unit 231 has multiple capacitors connected in parallel. The first terminals of the multiple capacitors are respectively connected to the load power supply terminal 210 and the first terminal of the discharge protection unit 232, and the second terminals of the multiple capacitors are grounded together.

[0046] Specifically, the first terminals of multiple capacitors are connected to both the load power supply terminal 210 and the first terminal of the discharge protection unit 232, forming a parallel energy storage structure. The second terminals of the multiple capacitors are grounded together, constituting a complete charging and discharging circuit. (See also...) Figure 2 The first terminal of the capacitor is the positive terminal, and the second terminal is the negative terminal. Multiple capacitors can be capacitors C43, C44, C42, C39, C40, and C38.

[0047] When the DC power conversion circuit 100 is working normally, the current charges the parallel capacitor bank through the unidirectional conduction circuit 220; when the output voltage of the DC power conversion circuit 100 drops due to a momentary power failure, the parallel capacitor bank discharges in an exponential decay manner, and its discharge process satisfies the formula V(t)=Vo*e^(-t / RC), where R is the equivalent resistance of the load and C is the total parallel capacitance.

[0048] like Figure 1 and Figure 2 As shown, in some embodiments, the discharge protection unit 232 includes a fifth transistor Q5 and a bias resistor R54. The base of the fifth transistor Q5 is connected to the output terminal of the DC power conversion circuit 100 through the bias resistor R54, the collector of the fifth transistor Q5 is connected to the second terminal of the energy storage voltage regulator unit 231, and the emitter of the fifth transistor Q5 is grounded.

[0049] The fifth transistor Q5 is a component that automatically controls the discharge behavior of the energy storage and voltage regulation unit 231 in response to the output voltage state of the DC-DC power conversion circuit 100. The fifth transistor Q5 is an NPN transistor, with its base connected to the output terminal of the DC-DC power conversion circuit 100 via a bias resistor R54 to receive the output voltage state of the DC-DC power conversion circuit 100. The collector of the fifth transistor Q5 is connected to the second terminal of the energy storage and voltage regulation unit 231, and the emitter of the fifth transistor Q5 is grounded, forming a complete discharge circuit. In some embodiments, the collector of the fifth transistor Q5 is connected to the first terminal of multiple capacitors.

[0050] The bias resistor R54 has a resistance of approximately 10kΩ.

[0051] For example, when the output voltage of the DC power conversion circuit 100 is the normal voltage, i.e., 12V, the base potential of the fifth transistor Q5 is higher than the emitter potential (approximately 0.7V or more), and the fifth transistor Q5 is in the off state. When the output voltage of the DC power conversion circuit 100 drops, the base potential of the fifth transistor Q5 is lower than the emitter potential, the fifth transistor Q5 turns on, and the energy storage and voltage regulation unit 231 discharges.

[0052] The fifth transistor Q5 is configured such that when the positive and negative terminals of the external power supply are reversed, causing the voltage at the output terminal of the DC power conversion circuit 100 to be zero, the base voltage of the fifth transistor Q5 is less than the emitter voltage of the fifth transistor Q5, causing the fifth transistor Q5 to conduct, thereby releasing the charge in the energy storage and voltage regulation unit 231.

[0053] The fifth transistor Q5 is configured such that when the load connected to the load power supply terminal 210 starts, the voltage at the output terminal of the DC power conversion circuit 100 drops, the base voltage of the fifth transistor Q5 is less than the emitter voltage of the fifth transistor Q5, causing the fifth transistor Q5 to conduct, thereby releasing the charge in the energy storage voltage regulator unit 231.

[0054] This embodiment also provides a time-delayed voltage holding method, applied in a power measuring instrument, the method comprising: When the DC power conversion circuit 100 outputs a normal voltage, it charges and stores energy in the delay voltage regulator circuit 230 through the unidirectional conduction circuit 220. When the load circuit 300 starts, causing a momentary drop in the voltage at the output terminal of the DC power conversion circuit 100, which is lower than the voltage at the load power supply terminal 210, the unidirectional conduction circuit 220 is cut off to isolate the output terminal of the DC power conversion circuit 100. The delay voltage regulator circuit 230 releases the stored electrical energy to the load power supply terminal 210, clamping the voltage at the load power supply terminal 210 within the preset operating voltage range until the output voltage of the DC power conversion circuit 100 is normal.

[0055] In the initial state, the DC power conversion circuit 100 receives a stable external power supply, which is approximately 20V. The DC power conversion circuit 100 outputs a stable output voltage, approximately 12V. The unidirectional conduction circuit 220 in the time-delay voltage holding device 200 is in the conducting state, allowing current to flow to the time-delay voltage regulator circuit 230. The energy storage capacitor in the time-delay voltage regulator circuit 230 is charged, and the discharge protection unit 232 is in the cut-off state.

[0056] When the load circuit 300 starts, for example, when measurement begins, the system enters an operational state: First, the instantaneous high current demand of the power measurement circuit 310 increases the load on the DC power conversion circuit 100, causing its output voltage to drop. When the output voltage of the DC power conversion circuit 100 drops below the voltage at the load power supply terminal 210, the unidirectional conduction circuit 220 automatically switches to the cutoff state, disconnecting the connection between the DC power conversion circuit 100 and the load circuit 300. Simultaneously, due to the drop in the output voltage of the DC power conversion circuit 100, the discharge protection unit 232 is activated. The energy storage capacitor begins to release stored energy to the load power supply terminal 210, maintaining voltage stability through exponential decay. The entire switching process is completed within 5μs, much faster than the rate at which the output voltage of the DC power conversion circuit 100 drops.

[0057] When the output voltage of the DC power conversion circuit 100 returns to the normal level, the unidirectional conduction circuit 220 is turned on again, the delay voltage regulator circuit 230 switches to the charging state, the fifth transistor Q5 is turned off, and the energy storage capacitor is recharged.

[0058] like Figure 3 and Figure 4 As shown, when the external power supply voltage is 20V, the power measurement circuit 310 starts. Using the yellow line as a reference line, the external power supply voltage will momentarily drop to near 0V. Figure 4 As shown, when the external 20V power supply outputs a stable 12V (denoted as VS) through the DC power conversion circuit 100, the power measurement circuit 310 can cause the output voltage VS of the DC power conversion circuit 100 to drop sharply from 12.0V to 5.28V at the moment of startup, resulting in system reset, sampling interruption or false triggering.

[0059] Figure 5 This is the voltage waveform at the load power supply terminal 210 after adding the time-delay voltage holding device 200. For example... Figure 5As shown, at the moment the power measurement circuit 310 starts, the voltage at the load power supply terminal 210 drops briefly to 1.84V, and then quickly stabilizes. From the periodic requirements of power startup, whether it's short-circuit current signal acquisition or power current signal acquisition, the time period is approximately 140ms, which can be calculated using the time constant formula V(t)=Vo*e^(-t / RC). However, in this embodiment, when the delayed voltage holding device 200 drops from 11.8V to 9.96V, the subsequent voltage holding time is approximately t=133ms; while in conventional application circuits, when the voltage drops from 12.0V to 5.28V, the subsequent voltage holding time is only approximately t=24ms, which cannot meet the operating conditions of high-power MOSFETs. Therefore, the delayed voltage holding device 200 in this application embodiment fully verifies the reliability of the delayed voltage holding scheme. When the input power fails momentarily, the circuit can provide short-term power to the subsequent working circuit through its own energy storage or voltage regulation mechanism, avoiding the direct collapse of the output voltage due to the input transient power failure, and ensuring the continuous operation of the subsequent power module.

[0060] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0061] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0062] The terms "coupled," "connected," or "connected" in the instruction manual include both direct and indirect connections. An indirect connection is a connection made through an intermediate medium, such as a connection made through an electrically conductive medium, which may have parasitic inductance or capacitance. An indirect connection may also include connections made through other active or passive devices to achieve the same or similar functional purpose, such as connections made through circuits or components such as switches or follower circuits.

[0063] In the detailed description of this specification, reference is made to the accompanying drawings, which form a part thereof, wherein like reference numerals always denote like parts, and wherein exemplary embodiments are shown by way of example that may be implemented. It should be understood that other embodiments may be utilized, and structural or logical changes may be made, without departing from the scope of this application. Therefore, the following detailed description should not be considered limiting.

[0064] The various operations in the specification may be described sequentially as multiple discrete actions or operations in a manner most conducive to understanding the claimed subject matter. However, the order of description should not be construed as implying that these operations must be sequentially related. Specifically, these operations may not be performed in the order presented. The described operations may be performed in a different order than in the described embodiments. Various additional operations may be performed in additional embodiments and / or the described operations may be omitted.

[0065] Various components and devices may be referred to or shown in the singular (e.g., “MOS transistor”, “transistor”, “switch”, etc.) in this document, but only for the convenience of discussion, and any element referred to in the singular may include multiple such elements as taught herein.

[0066] The above are merely preferred embodiments of this application and do not constitute any limitation on this application. Any person skilled in the art can make many possible variations and modifications to the technical solution of this application, or modify it into equivalent embodiments, without departing from the scope of the technical solution of this application. Therefore, all equivalent changes made based on the shape, structure, and principle of this application without departing from the content of the technical solution of this application should be covered within the protection scope of this application.

Claims

1. A time-delayed voltage holding device, wherein the device is disposed between the output terminal of a DC power conversion circuit and the load power supply terminal, characterized in that, The device includes: A unidirectional conduction circuit is connected in series between the output terminal of the DC power conversion circuit and the load power supply terminal. The unidirectional conduction circuit is configured to allow current to flow from the DC power conversion circuit to the load power supply terminal and to block reverse current from the load power supply terminal to the DC power conversion circuit. A time-delay voltage regulator circuit is connected between the load power supply terminal and the ground terminal; When the DC power conversion circuit outputs a normal voltage, the DC power conversion circuit charges the delay voltage regulator circuit through the unidirectional conduction circuit; when the output voltage of the DC power conversion circuit experiences a momentary drop, the unidirectional conduction circuit is in the off state, and the delay voltage regulator circuit discharges to the load power supply terminal to maintain the voltage level of the load power supply terminal.

2. The time-delay pressure-holding device according to claim 1, characterized in that, The unidirectional conduction circuit includes at least one conducting element. The first end of the conducting element is connected to the output end of the DC power conversion circuit, and the second end of the conducting element is connected to both the delay voltage regulator circuit and the load power supply end.

3. The time-delay pressure-holding device according to claim 2, characterized in that, The circuit has two conducting elements connected in parallel. One conducting element is a third diode, and the other conducting element is a fourth diode. The positive terminals of the third and fourth diodes are connected to the output terminal of the DC power conversion circuit, and the negative terminals of the third and fourth diodes are connected to the delay voltage regulator circuit and the load power supply terminal.

4. The time-delay pressure-holding device according to claim 1, characterized in that, The time-delay voltage regulator circuit includes an energy storage voltage regulator unit and a discharge protection unit. The first end of the energy storage voltage regulator unit is connected to the load power supply end, the first end of the discharge protection unit is connected to the second end of the energy storage voltage regulator unit, and the second end of the discharge protection unit is connected to the output end of the DC power conversion circuit.

5. The time-delay pressure-holding device according to claim 4, characterized in that, The energy storage and voltage regulation unit includes multiple capacitors connected in parallel. The first terminals of the multiple capacitors are respectively connected to the load power supply terminal and the first terminal of the discharge protection unit, and the second terminals of the multiple capacitors are grounded together.

6. The time-delay pressure-holding device according to claim 4, characterized in that, The discharge protection unit includes a fifth transistor and a bias resistor. The base of the fifth transistor is connected to the output terminal of the DC power conversion circuit through the bias resistor. The collector of the fifth transistor is connected to the second terminal of the energy storage voltage regulator unit. The emitter of the fifth transistor is grounded.

7. The time-delayed pressure-holding device according to claim 6, characterized in that, The fifth transistor is configured such that when the positive and negative terminals of the external power supply are reversed, causing the voltage at the output terminal of the DC power conversion circuit to be zero, the base voltage of the fifth transistor is less than the emitter voltage of the fifth transistor, causing the fifth transistor to conduct, thereby releasing the charge in the energy storage and voltage regulation unit.

8. The time-delayed pressure-holding device according to claim 6, characterized in that, The fifth transistor is configured such that when the load connected to the load power supply terminal starts, the voltage at the output terminal of the DC power conversion circuit drops, the base voltage of the fifth transistor is less than the emitter voltage of the fifth transistor, causing the fifth transistor to conduct, thereby releasing the charge in the energy storage and voltage regulation unit.

9. A power measuring instrument, characterized in that, include: A DC power conversion circuit, the DC power conversion circuit being configured to receive an external power supply voltage; The time-delayed voltage holding device according to any one of claims 1 to 8, wherein the time-delayed voltage holding device is connected to the DC power conversion circuit; A load circuit, the load circuit including a power measurement circuit, the power measurement circuit being connected to the load power supply terminal; The time-delay voltage holding device is configured to clamp the input voltage of the power measurement circuit within a preset operating voltage range during the period when the power measurement circuit is instantaneously activated, causing a momentary voltage drop at the output of the DC power conversion circuit.

10. A time-delayed voltage holding method, applied in the power measuring instrument of claim 9, characterized in that, The method includes: When the DC power conversion circuit outputs a normal voltage, the time-delay voltage regulator circuit is charged and stored through the unidirectional conduction circuit. When the load circuit starts up, causing a momentary drop in the voltage at the output of the DC power conversion circuit, which is lower than the voltage at the load power supply terminal, the unidirectional conduction circuit is cut off to isolate the output of the DC power conversion circuit. The time-delay voltage regulator circuit releases the stored electrical energy to the load power supply terminal, clamping the voltage at the load power supply terminal within the preset operating voltage range until the output voltage of the DC power conversion circuit is normal.

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