Blue Ring Tester Schematic Diagram Exclusive [exclusive] Jun 2026
A healthy coil will ring for dozens of cycles, while a shorted coil will barely ring at all. Exclusive Blue Ring Tester Schematic Diagram
+9V Battery / DC Source │ ├───[100uF]───┐ (Filter) │ ▼ GND ├───[100nF]───┐ (Bypass) │ ▼ GND │ [Test +] ────┼───────┬───────────────┐ │ │ │ [1k] [10nF] [1N4148] (Clamping) │ │ ▲ [Test -] ────┴───────┴───────────────┼─────────┐ │ │ (Pin 2) (Pin 3) ┌─────────────────┐ │ LM393 │───[10k Pull-up]───+9V │ Comparator │ └─────────────────┘ │ (Pin 1 Output) │ ▼ ┌─────────────────┐ │ LM3914 │───► [LED Bar Graph] │ Bar Graph Driver│ (8 to 10 LEDs) └─────────────────┘ Detailed Pin connections & Node Logic:
: High Q-factor resonance. The inductor is functioning beautifully with no shorted loops. blue ring tester schematic diagram exclusive
The decaying AC ringing waveform is fed into a high-speed voltage comparator (like the or an internal microcontroller comparator).
Note: This tester checks for shorted turns, not total inductance value. Always complement this tool with a standard LCR meter for a complete breakdown of component health. A healthy coil will ring for dozens of
A shorted coil causes the ringing to decay so quickly that the comparator only sees one or two zero-crossings. This is sensed by a simple RC network (R4, R6) that charges a capacitor. If the capacitor charges above a threshold (good coil), the green LED lights. If it fails to charge (bad coil), the red LED lights.
If your Blue Ring Tester stops working, here’s a quick checklist: The decaying AC ringing waveform is fed into
What are you planning to use for the pulse generation (CD4093, 555 timer, or an MCU)?
The circuit uses a low-frequency oscillator, often built from a 555 timer or a CMOS Schmidt trigger IC (like the 4049 or 4069). It generates a sharp square wave pulse at roughly 10 Hz to 20 Hz. This frequency gives the ringing cycle enough time to completely decay before the next pulse arrives. 2. The Pulse Driver
If you want, I can:
The schematic is organized into three distinct sections: