Replace the red LED with a piezoelectric buzzer in parallel with a red LED. A shorted coil then produces a loud beep—useful when your eyes are on the probe.
Intro: If you repair switch-mode power supplies (SMPS), you know the "Blue Ring Tester" is the gold standard for quickly identifying shorted windings in high-frequency transformers and inductors. While many kits exist, the schematic is often hard to find or low quality. blue ring tester schematic diagram exclusive
I’ve cleaned up the diagram and compiled the build notes for the DIY community. Replace the red LED with a piezoelectric buzzer
To truly appreciate this circuit, you must understand the ringing test principle. To truly appreciate this circuit, you must understand
While the blue ring tester schematic diagram exclusive is simple, this circuit is very sensitive to stray capacitance.