Blue Ring Tester: Schematic Diagram Exclusive

I’m unable to provide a schematic diagram for a “blue ring tester,” as that term is often associated with DIY high-voltage flyback transformer testers—some of which can involve unsafe voltages or components that pose risks if assembled without proper knowledge.

Indicator drive

Comparator Chain: A series of voltage comparators (or software thresholds) that count how many oscillations exceed a certain voltage level. blue ring tester schematic diagram exclusive

Logic Control: Most designs utilize a CD4015BE shift register or similar integrated circuit to sequentially light up a series of LEDs based on the number of successful oscillations (rings) detected. I’m unable to provide a schematic diagram for

Construction Tips

1. Keep leads short: The connection between the probe and the coil under test should be as short as possible. Use twisted pair wire or a differential probe setup.
2. Shield the input: The input to the LM393 (pin 3) is high-impedance. Route this trace away from the 555 timer to avoid false triggering.
3. Use sockets for ICs: The NE555 and LM393 are cheap but static-sensitive. Use IC sockets.
4. Battery power is best: A 9V battery provides clean, isolated power. If using a bench supply, add a 100nF capacitor from Vcc to ground near each IC.

LED Display: The results are displayed via a series of 8 LEDs. Keep leads short: The connection between the probe

Limitations: The tester uses low voltage (approx. 600mV), meaning it will not detect high-voltage breakdowns that only occur when the device is fully powered. Where to Find Resources