High-precision resistance loop tester schematic analysis

With the continuous development of electronic technology, high-precisionresistanceLoop testers play an increasingly important role in the manufacturing, maintenance and quality inspection of electronic equipment. It can accurately measure the resistance value, help engineers determine the health status of the circuit, and ensure the stable operation of the equipment. This article will focus on the "Principle Diagram of High-Precision Resistance Loop Tester" and analyze its working principle and core components in detail.

A high-precision resistance loop tester is an instrument specially used to measure the resistance value in a circuit. Compared with ordinary resistance testers, it has higher measurement accuracy and stronger anti-interference ability, and is suitable for micro-ohm level low resistance measurement. Its core is to achieve accurate detection of resistance through a stable power supply and high-precision measurement circuit.

High-precision resistance loop testers usually use low-noise, stable DC power supply as power supply. The stability of the power module directly affects the accuracy of the measurement. Therefore, a voltage stabilizing chip and a filter circuit must be used in the design to ensure the stability of the output voltage and avoid the impact of power supply fluctuations on the measurement results.

In order to obtain an accurate resistance value, the tester uses a constant current source circuit to supply a stable current to the resistor under test. The constant current source can ensure that the current does not change as the load changes, so that the measured voltage has a linear relationship with the resistance value. Commonly used constant current source designs include operational amplifiers and field effect transistors to achieve constant current output.

The voltage measurement part is the key link to obtain the voltage across the resistor being measured. High-precision testers usually use differential amplifiers with high input impedance to reduce measurement errors. At the same time, a low-noise operational amplifier and a high-resolution analog-to-digital converter (ADC) are used to improve the sensitivity and accuracy of measurement.

Since there are various interference signals in the measurement environment, the tester needs to filter the collected voltage signals. Common filtering methods include low-pass filtering and digital filtering, which can effectively suppress high-frequency noise and interference signals and ensure the stability and reliability of measurement data.

High-precision resistance loop testers must have calibration functions to ensure long-term measurement accuracy. Through the internal reference resistance and software algorithm, the measurement error can be compensated, eliminating the influence of factors such as temperature drift and contact resistance, and improving the credibility of the test results.

Testers are usually equipped with LCD screens that display measurement results and related parameters in real time. At the same time, it supports USB, Bluetooth and other interfaces to facilitate data transmission and remote monitoring to meet the needs of modern intelligent testing.

The high-precision resistance loop tester achieves accurate measurement of resistance value through stable power supply, constant current source circuit, high-precision voltage measurement and effective signal processing. The key to its schematic design is to ensure current stability, signal purity and error minimization. With the advancement of technology, such testers will be more widely used in the fields of electronic manufacturing and maintenance, providing solid support for the quality assurance of electronic equipment. Understanding its schematic structure helps engineers optimize the design and improve test efficiency and accuracy.