Electric signal detection method and circuit and switching power supply

Abstract

The invention discloses an electric signal detection method and circuit and a switching power supply. The electric signal detection circuit comprises an electric signal sampling unit for sampling and pre-processing an electric signal to obtain a voltage signal S1 representing the real-time size of the electric signal; a carrier generation unit which generates a carrier signal S2 of which the waveform comprises a period and an amplitude; a pulse modulation unit which modulates the voltage signal S1 and the carrier signal S2 to generate a pulse signal S3; a pulse edge processing unit which is used for carrying out differential processing on the pulse signal S3, obtaining the rising and falling edges of the pulse signal S3, obtaining a narrow pulse signal S4 with positive and negative polarities and outputting the narrow pulse signal S4; an isolation transmission unit which performs isolation processing on the narrow pulse signal S4 and outputs a narrow pulse signal S5; a pulse analysis unit which performs waveform shaping on the narrow pulse signal S5 and outputs a pulse signal S6 corresponding to the narrow pulse signal S5; and a signal detection unit which is used for capturing and quantitatively detecting and calculating the pulse signal S6 and outputting a detection signal S7. The electric signal detection circuit can meet the size and cost requirements of switching power supply development.

Description

technical field [0001] The invention relates to electrical signal detection, in particular to the electrical signal detection of input voltage and input current of a switching power supply. Background technique [0002] In the application of switching power supply, the main factors causing damage to switching power supply are input overvoltage damage, input undervoltage damage, etc. Therefore, it is necessary to detect the input voltage of switching power supply and carry out corresponding protection in time. In the new multifunctional and intelligent switching power supply, it is also necessary to detect the input voltage, input current, input power, conversion efficiency and power failure of the switching power supply in real time. The existing power frequency input voltage and input current detection schemes mainly include power frequency voltage transformers and power frequency current transformers, etc., but power frequency voltage transformers and power frequency curre...

AI Technical Summary

Problems solved by technology

The existing power frequency input voltage and input current detection schemes mainly include power frequency voltage transformers and power frequency current transformers, etc., but power frequency voltage transformers and power frequency current transformers are often relatively large in size and high in cost

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