: If there is a shorted turn or a bad diode within the transformer, the energy is quickly absorbed, causing the oscillations to damp out almost immediately. LED Indicator Guide
: Low Q (Quality Factor), typically indicating a bad or shorted winding. Yellow LEDs : Marginal or medium Q. Green LEDs : High Q, indicating a good component. Key Components & Resources
Add a 3-position switch to select C2 values:
For actual schematics, you can refer to the AnaTek Blue Ring Tester Assembly Manual for authorized designs. blue ring tester schematic diagram exclusive
If a shorted turn exists, the effective resistance of the coil is increased (due to eddy currents), causing the oscillation to dissipate quickly. 3. The Comparison and Display Section This section analyzes the oscillation decay.
Note: Refer to the official schematic for exact resistor and capacitor values.
When Q1 turns off abruptly, the magnetic field in the coil collapses, generating a flyback voltage spike. The coil and its parasitic capacitance form an LC tank circuit , causing the coil to ring (oscillate) at its resonant frequency. : If there is a shorted turn or
When the pulse stops, the magnetic field collapses, causing the inductor and a capacitor in the tester to resonate.
| LED Color | Meaning | Interpretation & Action | | :--- | :--- | :--- | | | Good (Normal) | High Q, low loss. The coil is likely healthy and functional. | | Yellow | Marginal (Acceptable) | Medium Q, moderate loss. The coil may be usable but could be degrading. | | Red | Bad/Faulty (Abnormal) | Low Q, high loss. This strongly suggests shorted turns or a damaged coil. |
The Blue Ring Tester is a testament to the idea that the right tool for the job can be simple, elegant, and incredibly effective. Its schematic diagram reveals a clever design that has stood the test of time. While it has limitations and isn't a substitute for a full-featured impedance analyzer, its ability to quickly separate good coils from bad ones makes it an invaluable asset for anyone who regularly works with high-frequency magnetics. Green LEDs : High Q, indicating a good component
This article is for educational purposes. Always observe safety procedures when working with high-voltage circuits. Flyback transformers and SMPS primaries can store lethal charges even when unplugged.
: A late design revision changed resistor R7 to 510 ohms to increase sensitivity for low-impedance components like horizontal deflection coils.