Alternating voltage sampling circuit

Abstract

The invention provides an alternating voltage sampling circuit which can conduct sampling on alternating voltages. The alternating voltage sampling circuit comprises an alternating power circuit L, an alternating power circuit N, and at least one voltage comparator which is connected with the alternating power circuit L and the alternating power circuit N. Sampling resistors are further connected between the alternating power circuit L and one voltage comparator, and between the alternating power circuit N and another voltage comparator, and the sampling resistors are glass glaze thick-film resistors which can resist alternating voltage impact. The alternating voltage sampling circuit has the advantages that due to the fact that the glass glaze thick-film resistors which can resist alternating voltage impact are arranged in the alternating voltage sampling circuit, the alternating voltage sampling circuit can conduct low voltage sampling, and in high alternating voltages, can also conduct sampling on the high alternating voltages stably and reliably, provides more accurate data, and further guarantees that the other components in the circuit can run more stably and reliably.

Description

technical field [0001] The invention relates to an AC voltage sampling circuit, in particular to an AC voltage sampling circuit capable of sampling high voltage. Background technique [0002] In the existing power supply protection circuit, low-voltage sampling is generally used for sampling the power line, which is converted into DC voltage after passing through the transformer and then sampled through the sampling resistor and related op-amp circuit. However, the sampling accuracy of this method is relatively poor and is restricted. In terms of device consistency, it cannot effectively reflect the actual value. At the same time, during the actual operation of the product, due to the uncertainty of the on-site voltage, there will often be power fluctuations, and sometimes even instantaneous voltage values ​​of thousands of volts. At this time, the voltage sampling resistor is directly connected to the power supply. Under the impact of thousands of volts of instantaneous vo...

AI Technical Summary

Problems solved by technology

[0002] In the existing power supply protection circuit, low-voltage sampling is generally used for sampling the power line, which is converted into DC voltage after passing through the transformer and then sampled through the sampling resistor and related op-amp circuit. However, the sampling accuracy of this method is relatively poor and is restricted. In terms of device consistency, it cannot effectively reflect the actual value

At the same time, during the actual operation of the product, due to the uncertainty of the on-site voltage, there will often be power fluctuations, and sometimes even instantaneous voltage values ​​of thousands of volts. At this time, the voltage sampling resistor is directly connected to the power supply. Under the impact of thousands of volts of instantaneous voltage, the voltage sampling circuit will often fail.

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