A sense circuit

Abstract

The invention discloses an SENSE circuit and belongs to the field of voltage measurement control. Through an impedance detection method, connecting state of an SENSE line is detected; through arrangement of a line voltage drop compensation voltage control circuit, when line voltage drop from an output side to a load side is large, connection between a detection line and a power output end is disconnected automatically, so that influence of line voltage drop can be reduced, and accuracy of output voltage at the load side is improved; when the line voltage drop increases furthermore, judgment onwhether the power supply exceeds the maximum compensation capacity is carried out according to a measured value of the local voltage in a voltage measurement circuit to determine whether to trigger an overvoltage protection action, thereby preventing power supply work abnormity and damage phenomenon due to excessive line voltage drop; since continuous SENSE detection is carried out in the whole working state, protection of the power supply is improved; and a differential filter and amplification circuit is adopted for voltage measurement, thereby effectively filtering out common-mode noise signals and ensuring good voltage measurement accuracy.

Description

technical field [0001] The invention belongs to the field of voltage measurement and control, and in particular relates to a SENSE circuit. Background technique [0002] In the power supply and source measurement unit, the sampling detection of the output voltage comes from the output terminal, so only the stability of the output terminal voltage can be guaranteed. Due to the impedance of the cable from the output terminal to the load, there will be a voltage drop at both ends of the cable, especially in the case of long distances and high currents, the voltage drop on the cable will increase sharply, resulting in a stable voltage at the load terminal Sexual deterioration. Therefore, in the high-precision and high-power programmable DC power supply and the source test unit, it is necessary to use the SENSE circuit for remote compensation, accurately measure the voltage on the load side, and adjust its output voltage according to the measurement results to compensate for the...

AI Technical Summary

Problems solved by technology

[0003] In the SENSE circuit, the detection line must be well connected to the load side. If one or two detection lines are falsely connected or disconnected, the detection line cannot detect the actual load side voltage, and the power supply will adjust its output voltage to rise sharply, causing the output power to change. large, the output regulation performance deteriorates, and may even damage the subsequent equipment. Therefore, traditional circuits often set a resistor with a fixed resistance between the detection line and the output end of the power supply. When the detection line fails to connect, the voltage at the output end can be detected for control. In order to prevent the occurrence of excessive voltage on the load side

However, this method cannot monitor the SENSE circuit in real time and detect the connection status of the SENSE line. At the same time, due to the influence of the output terminal, the voltage adjustment performance on the load side will deteriorate, especially when the line voltage drop from the output side to the load side is large. The output accuracy is significantly reduced, which cannot meet the output requirements of high-precision and high-power programmable DC power supply

In addition, the line voltage drop compensation capability of the SENSE circuit is limited, limited by the maximum output voltage (or power), when the sum of the voltage (or power consumption) on the transmission line and the voltage (or power) required by the load exceeds the allowable power supply When the maximum output capability of the power supply is exceeded, the power supply may work abnormally or be damaged, so it is necessary to limit the compensation capability of the power supply

Traditional methods cannot meet these requirements. In order to obtain safe and reliable high-power high-precision DC voltage output performance, it is necessary to find another way and adopt a new method

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