The ringing signal is AC-coupled via C4 and clamped by D1, D2 to protect the comparator. The LM393 compares the ringing waveform to ground. For a healthy coil, the ringing crosses zero many times. The comparator outputs a series of pulses for each zero-crossing.
The operation of a blue ring tester is based on the principle of . When the tester applies a fast, low-voltage pulse (typically under 600mV) to an inductor, it forms a temporary resonant "tank" circuit with the tester's internal capacitance. blue ring tester schematic diagram exclusive
Mains coupling / sensing input
The results are displayed across a series of colored LEDs (typically 8), providing a visual representation of the inductor's health. Blue Ring Tester Installation Guide | PDF - Scribd The ringing signal is AC-coupled via C4 and
A: No. An LC meter measures inductance and capacitance. The Blue Ring Tester measures Q factor and loss—a different parameter. The comparator outputs a series of pulses for