94. ESR_Meter..29 June 2025.

An ESR meter is a specialized electronic device used to measure the Equivalent Series Resistance (ESR) of capacitors—especially electrolytic ones—without needing to remove them from a circuit.

Here’s why that matters: over time, capacitors can degrade internally, increasing their ESR. Even if their capacitance value still looks fine, a high ESR can cause all sorts of problems in electronic circuits—like power supply instability, audio distortion, or complete failure to operate.

Unlike regular multimeters or capacitance testers, ESR meters apply a small AC signal (often at a few kHz) to detect this hidden resistance. That makes them incredibly handy for troubleshooting, especially in modern devices where bad capacitors can be sneaky culprits.

Want to know how to use one or maybe even build a simple version yourself?

In progress .Awaiting a few components.

7 transistor Schematic Diagram.

Box completed a/w calibration pot.

Wiring done and PCB mounted.

Some Designs for meter panel.

Description of wiring points.

ECR Meter.pdf

Download PDF • 301KB

7_transistor_ESR.zip

Download ZIP • 40KB