How to use a voltage tester pen to distinguish DC positive and negative
Measure the positive and negative poles of the DC, and look carefully at the neon tube of the electric pen. The front bright is negative, the rear bright is positive.
How to use a voltage tester pen to distinguish DC positive and negative
Measure the positive and negative poles of the DC, and look carefully at the neon tube of the electric pen. The front bright is negative, the rear bright is positive.
