The manganese copper shunt uses three leads to separate the power supply circuit from the sampling circuit, avoid voltage drop caused by the power supply current on the sampling lead, and ensure the accuracy of current measurement.

core principle

The power supply current only passes through one lead (such as the red lead) to avoid its voltage drop being superimposed on the sampling signal.

The sampling current passes through two other leads (such as blue and yellow leads), which have almost no current and therefore no voltage drop. The sampling signal only reflects the true voltage drop of the measured current on the manganese copper.  ‌

Analysis of pressure drop impact

The voltage drop generated by the power supply current (such as 27 μ V) may account for 1% of the sampling signal (when the current to be measured is 10A), or even higher (up to 10% at 1A), significantly affecting the measurement accuracy.  ‌

Fluctuations in lead resistance and meter power consumption can cause changes in voltage drop, resulting in interference signals.  ‌

Design advantages

The three wire separation structure effectively eliminates the interference of the power supply circuit on the sampling circuit and improves the measurement reliability.  ‌