Blue Ring Tester Schematic Diagram Exclusive [exclusive] Jun 2026

3-4 LEDs suggest a marginal component or a circuit with heavy parallel loading. 0-1 LEDs mean the component is almost certainly shorted. Conclusion

Over the past 15 years, dozens of forums have posted blurred, incomplete, or erroneous versions of this schematic. Here is what makes : blue ring tester schematic diagram exclusive

| Component | Value | Purpose | |-----------|-------|---------| | R1 | 10k | Base bias for Q1 | | R2 | 1k | Emitter current limit | | R4 | 10k | Signal output resistor | | R5 | 100k | Attenuation/filter resistor | | C2 | 100nF | Supply decoupling | | C3 | 1nF | High-pass filter | | C4 | 100pF | Low-pass filter (noise reduction) | | Q1 | 2N3904 | NPN switching transistor | | Lx | Unknown | Coil under test | 3-4 LEDs suggest a marginal component or a