Power detection circuit and operation method the same

Abstract

A power detection circuit is configured in a power supply unit having a primary side and a secondary side, and the power detection circuit includes a secondary side controller, a first voltage detection circuit, a second voltage detection circuit and a current detection circuit. The secondary-side controller calculates an output power according to an output voltage and an output current of the power supply unit, and obtains a first efficiency value according to the output power and an efficiency conversion table inside the secondary side controller, so as to calculate an input power of the power supply unit according to the first efficiency value and the output power.

Description

[Technical Field]

[0001] This disclosure relates to a power detection circuit and its operating method, and more particularly to a power detection circuit and its operating method that can estimate input power. [Previous Technology]

[0002] Issues such as carbon tax and carbon footprint are becoming clearer, and how to calculate the specific carbon emissions of products will be a key issue in the future. Specifically, carbon tax and carbon footprint are based on assigning a price to carbon dioxide (i.e., carbon pricing), treating carbon dioxide as a commodity that can be traded, transferred, and taxed. The reason for setting a price for "carbon dioxide" is that it accounts for the largest share of all greenhouse gas emissions, making it a priority target for control by various countries and international organizations. With the global push for energy conservation and environmental protection, various countries have introduced relevant carbon taxes and energy-saving standards. To meet environmental requirements, high power density and high efficiency are inevitable trends.

[0003] Generally, carbon emissions from product manufacturing are used as the standard. However, for power supply products such as power units (PSUs), the carbon emissions during operation are not to be underestimated due to their long operating times. Therefore, it is still necessary to understand the carbon emissions generated during the operation of such products to meet environmental protection requirements. Furthermore, the carbon emissions of power supplies during operation are generally calculated by converting the input power of the power supply into the amount of electricity consumed per hour. However, in power supplies with primary and secondary sides, traditional input power detection requires reading the voltage and current on the primary side and then transmitting them to the secondary side via an optocoupler for calculation. Therefore, to meet the power calculation requirements, traditional power supplies must have additional detection circuitry and optocouplers on the primary side, increasing the cost of the power supply and requiring additional configuration space.

[0004] Therefore, how to design a power detection circuit and its operation method to estimate the input power of the power supply by obtaining the secondary side parameters of the power supply is a major research topic that the creator of this case intends to study. [Summary of the Invention]

[0005] To solve the above problems, the present invention provides a power detection circuit, which is configured in a power supply having a primary side and a secondary side. The power detection circuit includes a secondary side controller, a first voltage detection circuit, a second voltage detection circuit, and a current detection circuit, with the secondary side controller configured on the secondary side. The first voltage detection circuit is coupled to the secondary side controller and provides a detection voltage based on the winding voltage of the secondary side. The second voltage detection circuit is coupled to the secondary side controller and the output terminal of the power supply, and detects the output voltage of the output terminal. The current detection circuit is coupled to the secondary side controller and the output terminal, and detects the output current of the output terminal. The secondary side controller calculates the input voltage of the power supply based on the detected voltage and obtains an efficiency conversion table under different output current conditions based on the input voltage; the secondary side controller calculates the output power based on the output voltage and output current, and obtains a first efficiency value of the power supply under the output current condition by comparing the output power with the efficiency conversion table, and calculates the input power of the power supply based on the first efficiency value and the output power.

[0006] To solve the above problems, the present invention provides an operation method for a power detection circuit. The power detection circuit is configured in a power supply having a primary side and a secondary side, and the operation method of the power detection circuit includes the following steps: (a) detecting the output voltage and output current at the output terminal of the power supply. (b) providing a detection voltage based on the winding voltage on the secondary side. (c) calculating the input voltage of the power supply based on the detection voltage, and obtaining an efficiency conversion table under different output current conditions based on the input voltage. (d) calculating the output power based on the output voltage and output current, and obtaining a first efficiency value of the power supply under the output current condition by comparing the output power with the efficiency conversion table. (e) calculating the input power of the power supply based on the first efficiency value and the output power.

[0007] The main purpose and effect of this disclosure is that the power supply disclosed herein can use a power detection circuit to detect the parameters obtained on the secondary side and obtain the input power of the power supply through estimation by the secondary side controller. Therefore, the power supply disclosed herein can use fewer components to detect the parameters on the secondary side to realize the function of estimating the input power, thereby achieving the effect of reducing circuit cost and circuit design complexity.

[0008] In order to further understand the technology, means and effects adopted by the present invention to achieve the intended purpose, please refer to the following detailed description and drawings of the present invention. It is believed that the purpose, features and characteristics of the present invention can be understood in depth and in detail from them. However, the accompanying drawings are provided for reference and illustration only and are not intended to limit the present invention.

Implementation Method

[0009] The technical content and detailed description of the present invention are explained below with reference to the accompanying drawings:

[0010] Please refer to Figure 1, which is a circuit block diagram of the power supply disclosed herein. The power supply 100 receives an input voltage Vin and converts the input voltage Vin into an output voltage Vo, so that the output voltage Vo is provided by the output terminal 100A to supply power to the load 200. The main conversion circuit architecture of the power supply 100 can be a switching converter with an isolation transformer, and it can be, for example, but not limited to, a flyback type, a forward type, etc., without limitation. Taking a flyback type conversion circuit as an example, the power supply 100 includes a primary side circuit 1, a transformer 2, a secondary side circuit 3, a primary side controller 4, and a secondary side controller 5, and the primary side winding 20 and the secondary side winding 22 of the transformer 2 divide the power supply 100 into a primary side and a secondary side.

[0011] Specifically, the primary-side circuit 1 and the primary-side controller 4 are configured on the primary side of the power supply 100, and the secondary-side circuit 3 and the secondary-side controller 5 are configured on the secondary side of the power supply 100. The primary-side circuit 1 may include, for example but not limited to, a primary-side rectifier circuit 10, a primary-side filter circuit 12, and a primary-side switch Q. The primary-side rectifier circuit 10 is coupled to the primary-side filter circuit 12, and the primary-side filter circuit 12 and the primary-side switch Q are coupled to the primary-side winding 20. The secondary-side circuit 3 may include, for example but not limited to, a secondary-side rectifier circuit 30 and a secondary-side filter circuit 32. The secondary-side rectifier circuit 30 is coupled to the secondary-side winding 22, and the secondary-side filter circuit 32 is coupled to the secondary-side rectifier circuit 30 and the output terminal 100A.

[0012] Furthermore, the secondary-side controller 5 provides a feedback signal Sf to the primary-side controller 4 based on the output voltage Vo provided by the power supply 100 and the output current Io required by the load 200, so that the primary-side controller 4 adjusts the pulse width modulation signal (PWM) according to the feedback signal Sf. The primary-side rectifier circuit 10 converts the input voltage Vin into a DC voltage Vdc, and the primary-side controller 4 controls the switching (on / off) of the primary-side switch Q by providing the PWM signal, causing the primary-side filter circuit 12 to store / release energy according to the DC voltage Vdc, so that the transformer 2 couples energy from the primary-side winding 20 to the secondary-side winding 22 according to the energy storage / release of the primary-side filter circuit 12. Furthermore, after rectification by the secondary-side rectifier circuit 30 and filtering by the secondary-side filter circuit 32, the output voltage Vo is provided to the output terminal 100A. On the other hand, the transformer 2 may also include an auxiliary winding 24, which mainly supplies power to the peripheral devices of the power supply 100 (such as, but not limited to, the secondary controller 5, the fan, etc.) by coupling the primary winding 20.

[0013] The secondary-side rectifier circuit 30 can be controlled to switch synchronously with the primary-side switch Q by the secondary-side rectifier controller 34 as shown in FIG1, but it can also be passively rectified by passive components (e.g., but not limited to diodes). In addition, the secondary-side controller 5 may or may not have a power delivery protocol (USB-PD). When the secondary-side controller 5 has a power delivery protocol, the secondary side of the power supply 100 may also include an isolating switch 6 (indicated by dashed lines). After the secondary-side controller 5 and the load 200 complete the handshake communication, the secondary-side controller 5 can turn on the isolating switch 6 to provide the output voltage Vo that meets the requirements of the load 200 to the output terminal 100A through the isolating switch 6, so as to avoid the risk of the power supply 100 incorrectly providing the output voltage Vo that does not meet the requirements of the load 200 to the load 200, causing the load 200 to fail or even be damaged.

[0014] Referring again to Figure 1, the power supply 100 further includes a power detection circuit 7, which includes a secondary-side controller 5, a first voltage detection circuit 70, a second voltage detection circuit 72, and a current detection circuit 74. The first voltage detection circuit 70 is coupled to the secondary-side controller 5 and provides a detection voltage Vs based on the secondary-side winding voltage Vw. The second voltage detection circuit 72 is coupled to the secondary-side controller 5 and the output terminal 100A, and provides a voltage signal Sv to the secondary-side controller 5 by detecting the output voltage Vo of the output terminal 100A. The current detection circuit 74 is coupled to the secondary-side controller 5 and the output terminal 100A, and provides a current signal Si to the secondary-side controller 5 by detecting the output current Io drawn by the load 200.

[0015] In one embodiment, the primary function of the secondary-side controller 5 is generally to provide a feedback signal Sf to the primary-side controller 4 based on the output voltage Vo provided by the power supply 100 and the output current Io required by the load 200. The secondary-side controller 5 is typically a microprocessor (MCU) or a digital signal processor (DSP). Generally, such processors can be programmed with custom code to implement custom functions. In addition to the original function of controlling the power supply 100, the secondary-side controller 5 disclosed herein also includes the function of estimating the input power Pin using only the parameters detected by the secondary side (e.g., but not limited to, the detected voltage Vs, output voltage Vo, output current Io, etc.).

[0016] Specifically, since the magnitude of the winding voltage Vw responds to the magnitude of the input voltage Vin, the secondary-side controller 5 can calculate the input voltage Vin of the power supply 100 based on the detected voltage Vs. The first voltage detection circuit 70 has multiple methods to provide the detected voltage Vs through the winding voltage Vw, enabling the secondary-side controller 5 to estimate the input voltage Vin; these are indicated by dashed lines here and will be further explained later. Furthermore, the secondary-side controller 5 can obtain an efficiency conversion table Et under different output current Io conditions based on the input voltage Vin. The efficiency conversion table Et can be pre-written into the secondary-side controller 5, or the operation of establishing the efficiency conversion table Et can be performed by testing with a test circuit, as will be further explained later.

[0017] Then, the secondary-side controller 5 determines the magnitudes of the output voltage Vo and output current Io based on the voltage signal Sv and the current signal Si, and calculates the output power Po based on the output voltage Vo and output current Io. Furthermore, the secondary-side controller 5 can obtain the first efficiency value of the power supply 100 under the current output current Io by comparing the output power Po with the efficiency conversion table Et. Finally, the secondary-side controller 5 calculates the input power Pin of the power supply 100 based on the first efficiency value and the output power Po. For example, assuming the output power Po is 36W, and the first efficiency value obtained from the efficiency conversion table Et is 0.9, the secondary-side controller 5 can estimate the input power Pin to be 40W, and so on. Therefore, through the above estimation method, the function of estimating the input power Pin can be achieved by detecting the secondary-side parameters using fewer components (i.e., the original secondary-side controller 5 combined with the detection circuit), thus achieving the effect of reducing circuit cost and circuit design complexity.

[0018] Referring again to FIG. 1, the power detection circuit 7 may optionally include a temperature detection circuit 76. The temperature detection circuit 76 is coupled to the secondary-side controller 5 and provides a temperature signal St to the secondary-side controller 5 by detecting a first ambient temperature inside the power supply 100 housing (not shown). Referring to FIG. 2, which is a temperature efficiency curve of the power supply disclosed herein, the ambient temperature of the power supply 100 is related to the efficiency of the power supply 100. Specifically, at the same output power Po, the higher the temperature, the higher the efficiency of the power supply 100, and vice versa. Taking FIG. 2 as an example, when the ambient temperature of the power supply 100 is 25 degrees and the output power Po is 40W, the efficiency is approximately 90%. However, when the temperature is 85 degrees, the output power is approximately 92%. Therefore, in order to more accurately estimate the input power Pin, when obtaining the first efficiency value, the value of the first efficiency value can be shifted according to the first ambient temperature, so as to obtain a more accurate input power Pin by adjusting the first efficiency value.

[0019] The power supply 100 can obtain the displacement of the first efficiency value under the influence of ambient temperature in various ways. For example, but not limited to, the power supply 100 can measure the efficiency curve at each ambient temperature through pre-testing. Alternatively, the power supply 100 can also obtain the displacement of the first efficiency value through the interpolation method. Specifically, the secondary-side controller 5 can preset a plurality of second ambient temperatures (taking the ambient temperatures of 25 degrees and 85 degrees in Figure 2 as examples). Furthermore, the secondary-side controller 5 can obtain two efficiency curves under different output current Io (corresponding to output power Po) conditions based on these two second ambient temperatures, so as to obtain two second conversion efficiency values ​​at a specific output power Po (i.e., when the output power Po is 40W, the second conversion efficiency values ​​are 90% and 92%, respectively). Thus, when the secondary controller 5 obtains the current output power Po and the current first ambient temperature, the secondary controller 5 calculates the first efficiency value corresponding to the first ambient temperature by using the parameter difference between the first ambient temperature and the two adjacent second ambient temperatures (i.e., ambient temperatures of 25 degrees and 85 degrees) through interpolation.

[0020] For example, when the output power Po is 65W and the second ambient temperature is 25 degrees Celsius, the second efficiency value is 88%, and when the second ambient temperature is 85 degrees Celsius, the second efficiency value is 90%. Therefore, the efficiency value of a single output power (i.e., 1W) can be considered as (90%-88%) / (85 degrees-25 degrees) = 2% / 60 degrees = 0.0333% / 1 degree. Therefore, when the output power Po is 65W, the efficiency of the power supply 100 will increase or decrease by 0.0333% for every 1 degree Celsius increase or decrease in the ambient temperature. Therefore, if the power supply 100 measures the current output power Po as 67W, its corresponding first efficiency value can be estimated as (67-25)*0.0333%+88%=89.398%. In this way, the power supply 100 can estimate the first efficiency value of a specific output power Po through interpolation calculation without obtaining a large number of parameters and their corresponding efficiency curves through pre-testing, thus reducing the significant time cost of pre-testing. Furthermore, since the calculated displacement of the first efficiency value is more accurate when the parameter differences are closer (for example, but not limited to, the curve for 67W differing from the actual tested 65W by only 2W), the secondary-side controller 5 can add several second ambient temperatures and their corresponding efficiency curves to improve the accuracy of the first efficiency value estimated by the power supply 100.

[0021] On the other hand, the power supply 100 disclosed herein may further include a transmission circuit 8, which is coupled to a secondary-side controller 5. The secondary-side controller 5 can primarily communicate with an external device (not shown) via the transmission circuit 8 (through transmission signal Ss), enabling the transmission circuit 8 to transmit parameters stored within the secondary-side controller 5 (e.g., but not limited to, the parameters mentioned above, or parameters such as electricity consumption calculated based on the input power Pin and the operating time of the power supply 100) to the external device (e.g., but not limited to, uploading to a system, cloud, host computer, or other physical or virtual device) via wired or wireless means. Alternatively, the external device can transmit parameters or control commands (e.g., but not limited to, efficiency conversion table Et, commands requesting parameter transmission, etc.) to control the secondary-side controller 5. In this way, the power supply 100 can possess edge computing and telemetry capabilities.

[0022] Please refer to Figure 3, which is a circuit block diagram of the power supply with test circuit disclosed herein, and also refer to Figures 1 and 2. The difference between Figure 3 and Figure 1 is that Figure 3 includes an external test circuit 9 applied to the power supply 100, and the test circuit 9 includes an energy meter 90 (E-Meter) and an optocoupler 92. Specifically, in addition to pre-writing the efficiency conversion table Et into the secondary-side controller 5, the power supply 100 disclosed herein can also perform measurements through the external test circuit 9 during operation of the power supply 100 and then send the data back to the secondary-side controller 5 to establish the efficiency conversion table Et. Furthermore, the energy meter 90 is coupled to the input terminal 100B of the power supply 100, and the optocoupler 92 is coupled to the energy meter 90 and the secondary-side controller 5. In one embodiment, the model of the energy meter 90 may be, for example, but not limited to, a 78M6610, but is not limited thereto.

[0023] The energy meter 90 primarily reads the input voltage Vin, input current Iin, and power factor via the coupled input terminal 100B, and transmits this information to the secondary-side controller 5 via the optocoupler 92, allowing the secondary-side controller 5 to establish an efficiency conversion table Et. Furthermore, after the efficiency conversion table Et is established, the energy meter 90 can be removed, allowing the secondary-side controller 5 to independently estimate the input power Pin of the power supply 100 based on the secondary-side parameters. Moreover, since the energy meter 90 is an external device and can be removed during actual operation of the power supply 100, the equipment cost of the power supply 100 can be significantly reduced, and the size of the power supply 100 can be significantly decreased. Therefore, the power supply 100 is particularly suitable for use in devices requiring a slim and compact design, such as adapters.

[0024] On the other hand, the test circuit 9 may optionally include a conversion circuit 94, which is coupled to the energy meter 90. The conversion circuit 94 mainly converts the external voltage V into the operating voltage Vcc to power the energy meter 90. Furthermore, the external voltage V can be provided by an external device or taken from any node of the power supply 100 (e.g., but not limited to, DC voltage Vdc), and is not limited thereto.

[0025] Please refer to Figure 4, which is a circuit diagram of the current detection circuit and temperature detection circuit disclosed herein, and also refer to Figures 1-3. The temperature detection circuit 76 may include a temperature control resistor Rn, and the temperature control resistor Rn is coupled to the secondary-side controller 5. The temperature control resistor Rn generates a temperature control resistance value according to the first ambient temperature, and the secondary-side controller 5 provides a current I through a current source (not shown) so that the temperature control resistor Rn generates a temperature control voltage Vt (i.e., temperature signal St) according to the current I and the temperature control resistance value. Furthermore, the secondary-side controller 5 can know the first ambient temperature according to the temperature control voltage Vt, and adjust the first efficiency value according to the first ambient temperature. In one embodiment, the temperature control resistor Rn may be a negative temperature coefficient resistor (NTC), but it is not limited thereto. Any component such as a resistor whose resistance value can change according to the ambient temperature should be included in the scope of this embodiment. In addition, in one embodiment, besides the embodiment shown in Figure 4, the power supply 100 may have various circuit architectures that can implement the temperature detection circuit 76. Therefore, any implementation of the temperature detection circuit 76 that can determine the first ambient temperature based on the temperature control voltage Vt should be included within the scope of this embodiment.

[0026] The current detection circuit 74 includes a current detection resistor Ri, which is coupled to the output terminal 100A and the secondary-side controller 5. When the output current Io flows through the current detection resistor Ri, a current detection voltage Vi (i.e., a current signal Si) is generated in the current detection resistor Ri. Therefore, the secondary-side controller 5 can determine the magnitude of the output current Io based on the current detection voltage Vi. In one embodiment, in addition to the implementation shown in FIG. 4, the power supply 100 may have various circuit architectures that can implement the current detection circuit 74. Therefore, any implementation of the current detection circuit 74 that can determine the output current Io based on the current detection voltage Vi should be included in the scope of this embodiment. Furthermore, in one embodiment, the current detection circuit 74 is not limited to being coupled only to the output terminal 100A to directly detect the output current Io; it can also be coupled to other locations of the power supply 100 (e.g., but not limited to, the secondary-side winding 22) to indirectly detect the output current Io.

[0027] Please refer to Figure 5A, which is a circuit diagram of a first embodiment of the first voltage detection circuit disclosed herein, and also refer to Figures 1-4. In Figure 5A, the secondary-side rectifier circuit 30 includes a secondary-side switch SR, and the secondary-side switch SR is disposed at the positive terminal 100+ of the secondary-side bus. The first voltage detection circuit 70 is coupled between the negative terminal 100- of the secondary-side bus and the ground terminal GND, and the first voltage detection circuit 70 includes a voltage divider circuit CD. The voltage divider circuit CD is coupled between the negative terminal 100- of the secondary-side bus and the ground terminal GND, and the voltage divider circuit CD may include a first resistor R1 and a second resistor R2 connected in series. Taking a flyback switching circuit as an example, when the primary-side switch Q is turned on, the secondary-side switch SR is not turned on. At this time, the primary-side current (indicated by the arrow) flows from the primary-side winding 20 to the primary-side switch Q, and the energy is coupled through the primary-side winding 20 to the secondary-side winding 22 to generate a winding voltage Vw in the secondary-side winding 22. Because the primary winding 20 and the secondary winding 22 have opposite polarities (i.e., their terminals are opposite), and the secondary switch SR is not conducting, the voltage divider circuit CD divides the winding voltage Vw (current is indicated by arrows), generating a detection voltage Vs at node P1 between the first resistor R1 and the second resistor R2. Furthermore, when the primary switch Q is conducting and the secondary switch SR is not conducting, the magnitude of the winding voltage Vw responds to the magnitude of the DC voltage Vdc (which is, for example, but not limited to, -Vdc * turns ratio), and the magnitude of the DC voltage Vdc corresponds to the magnitude of the input voltage Vin. Therefore, the detection voltage Vs reflects the input voltage Vin, allowing the secondary controller 5 to calculate the magnitude of the input voltage Vin based on the magnitude of the detection voltage Vs.

[0028] On the other hand, the first voltage detection circuit 70 may optionally include a diode D and a capacitor C. The diode D is connected in series between the secondary winding 22 and node P1, and the capacitor C is connected in parallel with the second resistor R2. The diode D is mainly used to prevent current from flowing back to the secondary side from the first voltage detection circuit 70 when the secondary side switch SR is switched, and the capacitor C is mainly used to stabilize the voltage level of the detected voltage Vs when the secondary side switch SR is switched, so that the secondary side controller 5 can more accurately determine the magnitude of the input voltage Vin.

[0029] Please refer to Figure 5B, which is a circuit diagram of the second embodiment of the first voltage detection circuit disclosed herein, and refer in conjunction with Figures 1-5A. The difference between the first voltage detection circuit 70 in Figure 5B and Figure 5A is that the secondary-side switch SR is configured at the negative terminal 100- of the bus, and the first voltage detection circuit 70 is coupled between the positive terminal 100+ of the bus and the ground terminal GND. The first voltage detection circuit 70 includes a clamping circuit CC, and the clamping circuit CC is coupled between the positive terminal 100+ of the bus and the ground terminal GND. The clamping circuit CC includes a capacitor C and a first resistor R1 connected in series, and a second resistor R2 is connected in parallel with the capacitor C and the first resistor R1. Similarly, when the secondary-side winding 22 generates a winding voltage Vw, the clamping circuit CC clamps the winding voltage Vw (current is indicated by arrows) to generate a detection voltage Vs at node P1 between the capacitor C and the first resistor R1, and the capacitor C can also be used to stabilize the voltage level of the detection voltage Vs.

[0030] On the other hand, the first voltage detection circuit 70 may also optionally include a diode D and a voltage divider circuit CD. The diode D is also used to prevent current from flowing back to the secondary side from the first voltage detection circuit 70 when the secondary-side switch SR is switched. The voltage divider circuit CD includes a third resistor R3 and a fourth resistor R4 connected in series between node P1 and ground terminal GND. The secondary-side controller 5 is coupled to node P2 between the third resistor R3 and the fourth resistor R4. The voltage divider circuit CD is mainly used to divide the detected voltage Vs into a voltage level suitable for the secondary-side controller 5 to read.

[0031] Please refer to Figure 5C, which is a circuit diagram of the third embodiment of the first voltage detection circuit disclosed herein, and also refer to Figures 1-5B. The difference between the first voltage detection circuit 70 in Figure 5C and Figure 5A is that the first voltage detection circuit 70 includes an auxiliary winding 24. The auxiliary winding 24 is used to couple the primary winding 20, and the polarity of the dotted terminals of the auxiliary winding 24 is the same as that of the secondary winding 22 (i.e., the dotted terminals are the same). When the primary side current (indicated by the arrow) flows from the primary side winding 20 to the primary side switch Q, energy is coupled through the primary side winding 20 to the secondary winding 22 and the auxiliary winding 24, causing the auxiliary winding 24 to generate a winding voltage Vw. The first voltage detection circuit 70 provides a detection voltage Vs based on the winding voltage Vw of the auxiliary winding 24, so that the secondary side controller 5 can calculate the magnitude of the input voltage Vin based on the magnitude of the detection voltage Vs.

[0032] On the other hand, the winding voltage Vw of the auxiliary winding 24 can also be selectively used to power the secondary-side controller 5, so that the secondary-side controller 5 can receive the required detection voltage Vs to control the secondary side. Specifically, the first voltage detection circuit 70 may also include a diode D and a capacitor C. The capacitor C is connected in parallel with the auxiliary winding 24, and the diode D is coupled between the auxiliary winding 24 and the capacitor C. Specifically, the diode D is used to rectify the winding voltage Vw, and the capacitor C is used to store and stabilize the voltage level of the detection voltage Vs. The power supply pin of the secondary-side controller 5 is coupled to the capacitor C to receive the detection voltage Vs and enable it to control the secondary side. In one embodiment, in addition to the embodiments shown in FIG5A-5C, the power supply 100 has various circuit architectures that can implement the first voltage detection circuit 70. Therefore, any implementation of the first voltage detection circuit 70 that allows the input voltage Vin to be determined from the secondary winding voltage Vw should be included within the scope of this embodiment. It is worth noting that in one embodiment, since the detection method in FIG5C directly obtains the winding voltage Vw to determine the input voltage Vin, the secondary-side switch SR in the circuit architecture of FIG5C is not limited to being configured at either the positive terminal 100+ or ​​the negative terminal 100- of the bus. This allows the circuit architecture of FIG5C to improve the applicability of the power detection circuit 7 and also simplifies the circuit design of the first voltage detection circuit 70.

[0033] Please refer to Figure 6, which is a flowchart of the operation method of the power detection circuit disclosed herein, and refer to Figures 1-5C in conjunction. The power supply 100 disclosed herein can achieve the function of estimating the input power Pin using fewer components (i.e., the original secondary-side controller 5 combined with the detection circuit) by detecting and estimating the power through the power detection circuit 7 configured only on the secondary side, thereby reducing circuit cost and circuit design complexity. Specifically, the operation method of the power detection circuit 7 includes detecting the output voltage Vo and output current Io of the output terminal 100A of the power supply 100 (S100). In a preferred embodiment, the output voltage Vo and output current Io of the power supply 100 are detected by coupling the second voltage detection circuit 72 and the current detection circuit 74 to the output terminal 100A of the power supply 100, respectively. Then, a detection voltage Vs is provided based on the winding voltage Vw on the secondary side (S200). A preferred embodiment is that the first voltage detection circuit 70 detects the winding voltage Vw in response to the input voltage Vin, and provides a detection voltage Vs based on the winding voltage Vw.

[0034] Then, the input voltage Vin of the power supply 100 is calculated based on the detected voltage Vs, and the efficiency conversion table Et under different output current Io conditions is obtained accordingly based on the input voltage Vin (S300). Since the winding voltage Vw can respond to the magnitude of the input voltage Vin, a preferred embodiment is to use the power detection circuit 7 to calculate the input voltage Vin of the power supply 100 based on the detected voltage Vs, and obtain the efficiency conversion table Et under different output current Io conditions accordingly based on the input voltage Vin. The efficiency conversion table Et can be pre-written into the secondary side controller 5, or the operation of establishing the efficiency conversion table Et can be performed by testing the test circuit. Then, the output power Po is calculated based on the output voltage Vo and the output current Io, and the first efficiency value of the power supply 100 under the output current Io condition is obtained by comparing the output power Po with the efficiency conversion table Et (S400). A preferred implementation method is to use the power detection circuit 7 to calculate the output power Po based on the output voltage Vo and the output current Io, and to obtain the first efficiency value of the power supply 100 under the current output current Io by comparing the output power Po with the efficiency conversion table Et.

[0035] Finally, the input power Pin of the power supply 100 is calculated based on the first efficiency value and the output power Po (S500). A preferred embodiment is to use the power detection circuit 7 to calculate the input power Pin of the power supply 100 based on the first efficiency value and the output power Po. In this way, the function of estimating the input power Pin can be achieved by detecting secondary-side parameters using only a few components. In one embodiment, the detailed operation method disclosed herein can be referred to in conjunction with Figures 1-5C, and will not be repeated here. Furthermore, in one embodiment, the circuits and components mentioned in the above steps are merely devices more suitable for implementing the above steps, but are not limited thereto. Any circuits and components that can achieve the operation mode in steps S100-S500 should be included within the scope of this embodiment.

[0036] Please refer to Figure 7A, which is a flowchart of the power supply power consumption calculation method disclosed herein, and Figure 7B, which is a waveform diagram of the power supply power consumption calculation method disclosed herein, and refer to Figures 1-6 in conjunction. Figures 7A and 7B mainly show one application of the power detection circuit 7, which is mainly used for power supply 100 power consumption measurement to calculate the carbon emissions of power supply 100 during operation. Specifically, as shown in Figures 7A and 7B, the secondary-side controller 5 can set a specific time period TD (e.g., but not limited to, 1 hour), and the secondary-side controller 5 can control the first voltage detection circuit 70 to sample the output voltage Vo of power supply 100 at multiple sampling times Ts within the specific time period TD, and simultaneously control the current detection circuit 74 to sample the output current Io of power supply 100 at the sampling time Ts (step S600). In one embodiment, Figure 7B shows a periodic sampling time Ts (e.g., but not limited to 1 second), but it is not limited to this and can also be a non-periodic sampling time Ts. For example, but not limited to, when the output current Io changes, multiple samples are taken, and when the output current Io does not change, no samples are taken. This logic can be applied in the same way (for example, but not limited to changes in ambient temperature), which will not be elaborated here.

[0037] Then, the obtained output voltage Vo and output current Io are used to calculate the input power Pin using the operation method shown in Figure 6 (step S620). After step S620, the number of samples is accumulated (step S640), and it is determined whether the specific time period TD has ended (step S660, for example, but not limited to, whether 3600 samples have been taken over 1 hour). If the specific time period TD has not ended, the process returns to step S600 to continue sampling the output voltage Vo and output current Io. Conversely, if the specific time period TD has ended, the electricity consumption of the power supply 100 during the specific time period TD is obtained based on the accumulated input power Pin parameter (step S680, the electricity consumption calculation method can be kilowatt-hours). In this way, the carbon emissions of the power supply 100 during operation can be calculated, facilitating the collection and disclosure of carbon emission data.

[0038] In addition, between steps S600 and S620, the first efficiency value can be selectively corrected based on the ambient temperature (step S610). Specifically, the secondary-side controller 5 can simultaneously control the temperature detection circuit 76 to sample the first ambient temperature of the power supply 100 at the sampling time Ts, and adjust the first efficiency value corresponding to each output power Po according to the first ambient temperature, so as to calculate a more accurate input power by using the adjusted first efficiency value and the currently obtained output power Po. It is worth mentioning that, in one embodiment, Figures 7A-7B are only one of the many application methods of the power detection circuit 7, and are not limited to its application only in calculating electricity consumption.

[0039] However, the above description is only a detailed description and drawings of preferred embodiments of the present invention. However, the features of the present invention are not limited thereto and are not intended to limit the present invention. The scope of the present invention should be determined by the following claims. All embodiments that are in line with the spirit of the claims and similar variations thereof should be included in the scope of the present invention. Any variations or modifications that can be easily conceived by those skilled in the art within the field of the present invention can be covered by the following claims. [Simplified Explanation of the Diagram]

[0040] Figure 1 is a circuit block diagram of the power supply disclosed herein;

[0041] Figure 2 is a temperature efficiency curve of the power supply disclosed herein;

[0042] Figure 3 is a circuit block diagram of the power supply and test circuit disclosed herein;

[0043] Figure 4 is a circuit diagram of the current detection circuit and temperature detection circuit disclosed herein;

[0044] Figure 5A is a circuit diagram of a first embodiment of the first voltage detection circuit disclosed herein;

[0045] Figure 5B is a circuit diagram of a second embodiment of the first voltage detection circuit disclosed herein;

[0046] Figure 5C is a circuit diagram of a third embodiment of the first voltage detection circuit disclosed herein;

[0047] Figure 6 is a flowchart of the operation method of the power detection circuit disclosed herein;

[0048] Figure 7A is a flowchart of the electricity calculation method for the power supply disclosed herein; and

[0049] Figure 7B is a waveform diagram of the power supply calculation method disclosed herein.

Claims

1. A power detection circuit configured in a power supply having a primary side and a secondary side, the power detection circuit comprising: a primary side controller configured on the secondary side; a first voltage detection circuit coupled to the secondary side controller and providing a detection voltage based on a winding voltage on the secondary side; a second voltage detection circuit coupled to the secondary side controller and an output terminal of the power supply, and detecting an output voltage at the output terminal; and a current detection circuit coupled to the secondary side controller and the output terminal, and detecting an output current at the output terminal; wherein... The secondary controller calculates an input voltage of the power supply based on the detected voltage, and obtains an efficiency conversion table under different output current conditions based on the input voltage; the secondary controller calculates an output power based on the output voltage and the output current, and obtains a first efficiency value of the power supply under the output current condition by comparing the output power with the efficiency conversion table, so as to calculate an input power of the power supply based on the first efficiency value and the output power.

2. The power detection circuit as described in claim 1, further comprising: A temperature detection circuit is coupled to the secondary-side controller and detects a first ambient temperature of the power supply; wherein the secondary-side controller adjusts the first efficiency value according to the first ambient temperature.

3. The power detection circuit as claimed in claim 2, wherein the secondary-side controller presets a plurality of second ambient temperatures and obtains a plurality of second conversion efficiency values ​​under different output current conditions based on the second ambient temperatures; the secondary-side controller calculates the first efficiency value corresponding to the first ambient temperature by using an internal difference between a parameter difference between the first ambient temperature and two adjacent second ambient temperatures.

4. The power detection circuit as claimed in claim 2, wherein the temperature detection circuit comprises: A temperature-controlled resistor generates a temperature-controlled resistance value based on the first ambient temperature, and the secondary-side controller knows the first ambient temperature based on the temperature-controlled resistance value, so as to adjust the first efficiency value according to the first ambient temperature.

5. The power detection circuit as claimed in claim 1, wherein the secondary side includes a primary-side switch disposed at the positive terminal of a bus, and the first voltage detection circuit includes: A voltage divider circuit is coupled between a negative terminal of a bus on the secondary side and a ground terminal, and includes a first resistor and a second resistor connected in series; wherein, when the secondary side switch is not turned on, the voltage divider circuit divides the winding voltage of the primary side winding on the secondary side to generate the detection voltage at a node between the first resistor and the second resistor.

6. The power detection circuit as claimed in claim 1, wherein the secondary side includes a primary-side switch disposed at the negative terminal of a bus, and the first voltage detection circuit includes: A clamping circuit is coupled between a positive terminal of a bus and a ground terminal on the secondary side, and includes a capacitor and a first resistor connected in series, and a second resistor connected in parallel with the capacitor and the first resistor; wherein, when the secondary side switch is not turned on, the clamping circuit clamps the winding voltage of the primary side winding on the secondary side, so as to generate the detection voltage at a node between the capacitor and the first resistor.

7. The power detection circuit as claimed in claim 1, wherein the first voltage detection circuit comprises: An auxiliary winding is coupled to a primary-side winding on the primary side, and the first voltage detection circuit provides the detection voltage based on the winding voltage of the auxiliary winding.

8. The power detection circuit as claimed in claim 1, wherein the first voltage detection circuit samples a plurality of output voltages at a plurality of sampling times within a specific time period, and the current detection circuit samples a plurality of output currents at the sampling times; the secondary-side controller calculates a plurality of input power corresponding to the output voltages and the output currents, and obtains a power consumption of the power supply within the specific time period based on the input power.

9. The power detection circuit as claimed in claim 8, wherein the secondary-side controller detects a plurality of first ambient temperatures of the power supply at the sampling times, and adjusts a plurality of first efficiency values ​​according to the first ambient temperatures.

10. A method of operating a power detection circuit, the power detection circuit being configured in a power supply having a primary side and a secondary side, the method of operating the power detection circuit comprising the following steps: detecting an output voltage and an output current at an output terminal of the power supply; providing a detection voltage based on a winding voltage on the secondary side; calculating an input voltage of the power supply based on the detection voltage, and obtaining an efficiency conversion table under different output current conditions based on the input voltage; calculating an output power based on the output voltage and the output current, and obtaining a first efficiency value of the power supply under the output current condition by comparing the output power with the efficiency conversion table; and calculating an input power of the power supply based on the first efficiency value and the output power.

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