Blue Ring Tester Schematic Diagram Exclusive [better] -

A standard ohmmeter cannot detect a single shorted turn in a transformer. The resistance change is too small to measure.

Blue Ring Tester is a specialized diagnostic tool used to identify shorted windings in high-Q inductive components like flyback transformers (FBT), switch-mode power supply (SMPS) transformers, and deflection yokes. Unlike a standard ohmmeter, which only measures DC resistance, a ring tester applies a fast voltage pulse to the component and counts the resulting resonant "rings" (damped oscillations) to determine its quality factor, or Core Schematic & Component Overview

Older schematics omit the calibration trimpot entirely. Without RV1, the tester is unreliable for different inductance ranges. Our schematic includes a in series with R5. Calibration procedure:

: PIC16F628A or ATtiny2313 (programmed with Ring Tester firmware). Comparator : LM393 (Dual differential comparator). blue ring tester schematic diagram exclusive

This is a simplified representation. An actual PCB layout includes additional filtering and protection.

Short the test leads together. The display should show zero LEDs or only the first red LED.

Mains coupling / sensing input

[Pulse Microcontroller] ---> [Pulse Transistor] ---> [Protection Circuit] <==> [Inductor Under Test] || [10nF Tuning Cap] || [LED Display (8-10 Blue)] <--- [Microcontroller Counter] <--- [LM393 Comparator] Component Selection and Bill of Materials (BOM)

Always desolder at least one leg of the transformer or yoke from the circuit board before testing to prevent in-circuit components from dampening the ring.

This exclusive guide breaks down the circuit schematic, explains how the "ring test" works, and provides a step-by-step blueprint to build your own tester. What is a Blue Ring Tester? A standard ohmmeter cannot detect a single shorted

10µF electrolytic capacitors for input/output noise filtering. 2. Pulse Generation & Tank Circuit This is where the stimulation pulse is created.

A voltage divider sets a clean reference threshold (approx. 10mV to 50mV above the noise floor) on the inverting pin.