Modulation direct-current voltage transformer

Abstract

The invention provides a modulation direct-current voltage transformer which comprises a pulse generator, a modulation circuit, a micro-current transformer and a synchronous rectifier circuit. The pulse generator is used for generating square waves and outputting alternate square wave signals through two output pins. The synchronous rectifier circuit is used for converting pulse alternating voltage to be direct-current voltage to be output. The modulation circuit comprises a first photoelectric coupler and a second photoelectric coupler. A primary coil of the micro-current transformer is serially connected between a first resistor and a second resistor, a secondary coil of the micro-current transformer is connected with a sampling resistor in parallel, and the sampling resistor is connected with the synchronous rectifier circuit. A primary circuit in the modulation direct-current voltage transformer does not need to provide auxiliary power supplies and precise analog devices, can achieve high voltage separation and linear direct-current voltage measurement easily, achieves the purposes of being simple in structure, low in cost and good in linearity and measuring direct-current voltage in separation mode, and can replace the traditional circuit to obtain high economic benefit.

Description

technical field [0001] The invention belongs to the field of DC voltage detection with electrical isolation, and in particular relates to a modulated DC voltage transformer. Background technique [0002] It is often necessary to measure DC voltage on low-voltage electrical appliances such as inverters, variable frequency power supplies, and intelligent power supplies. These voltages are generally at one end of the power line and have a relatively high voltage (300-1000V). The control circuit generally needs to be isolated from the power line. At present, the control circuit isolation measurement DC voltage is mainly used figure 1 The method described in , that is, the DC voltage input is output through a linear constant current circuit, a linear optocoupler, and a current-voltage conversion circuit. The isolation of this traditional method is not ideal, and the linearity of the measurement results is poor. Contents of the invention [0003] Aiming at the deficiencies of ...

AI Technical Summary

Problems solved by technology

At present, the control circuit isolation measurement DC voltage is mainly used figure 1 The method described in , that is, the DC voltage input is output through a linear constant current circuit, a linear optocoupler, and a current-voltage conversion circuit. The isolation of this traditional method is not very ideal, and the linearity of the measurement results is poor.

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