Power detection method and circuit for primary side circuit of power supply unit

Abstract

The invention discloses power detection method and circuit for a primary side circuit of a power supply unit. The power detection method uses a voltage sampling program, a current sampling program and a power calculation program. The voltage sampling program captures alternating-current voltage signal of mains supply and raises direct current level of the alternating-current voltage signal of the mains supply; negative half-cycle voltage signal serves as positive voltage level; the alternating-current voltage signal is digitally converted into direct-current sinusoidal signal; and voltage sampling is performed at certain time intervals to obtain a voltage root mean square value. The current sampling program captures alternating current signal of the mains supply and then analogically convert the alternating current signal into direct-current sinusoidal signal; and current sampling is performed at certain time intervals to obtain a current mean root square value. The power calculation program reads voltage and current sampled values for each capture, multiplies the values, and divides by a cycle time to obtain a power value.

Description

technical field [0001] The invention relates to a power detection method of a power supply, in particular to a low-cost and high-precision primary side circuit power detection method. Background technique [0002] At present, general computers or high-end computers, such as power supplies used in servers, all have the ability of two-way communication with the motherboard. In order to ensure that the computer can be turned on and off normally or the sequence of turning on and off the server, the power supply must report the current primary side voltage value, current value and power in addition to detecting that the output power is stable after starting up and actively notifying the motherboard of the current good power supply signal. value, so that the power-consuming computer can grasp the power consumption status of the power supply. Therefore, how the power supply meets the data required by the computer to report the power consumption status has attracted the attention o...

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Problems solved by technology

[0005] It can be seen from the above description that in order to provide accurate calculation of the primary side voltage value, current value and power value, a high-cost power measurement IC is used, and because the signal format of the power measurement IC is different from that of the primary side microprocessor, so An additional signal conversion processor must be added, which further increases the cost of the overall power supply; therefore, the current circuit of the power supply that reports the power consumption status of the primary side circuit needs to be further improved

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