ESR meter

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Guy Fernando (M0OOX) presents in this article, instructions to build an ESR (Equivalent Series Resistance) meter for testing the health of electrolytic capacitors. The instrument displays capacitance and ESR on a digital LCD readout, with an optional audible tone indicating the condition of the capacitor under test. At the heart of the meter is a 14-pin PIC microcontroller, using just a handful of other cheap components a feature rich ESR meter is easily constructed.

LCD animation

  • Digital LCD readout
  • ESR range 0.01Ω to 50Ω
  • Testing frequency 100kHz
  • Low test voltage for in-circuit testing
  • Audible test result tones
  • Auto power down
  • Automatic testing of capacitor
  • Probe resistance compensation
  • Battery supply voltage compensation
  • Capacitor stored charge protection
  • Low and high battery warning
  • Open / short circuit probe detection

Simple circuit diagram

Schematic diagram

Easy to construct

Wiring components to the main-board

At the heart of the ESR meter design is a PIC16F1705 PIC microcontroller. If you would like to try building this project yourself, the PIC may be purchased below through PayPal fully pre-programmed and ready for use. The price includes postage and packing via a Royal Mail "Tracked and Signed" service.

Please select the correct delivery region for your location from the dropdown list below. Select "UK mainland delivery" for deliveries within the United Kingdom, "European delivery" for deliveries within other European countries, or "Worldwide delivery" for all other international country destinations.

Buy the PIC for the ESR Meter

Programmed PIC16F1705

PIC16F1705 PIC Microcontroller
Pre-Programmed Firmware for ESR Meter
Version v1.01

After dispatch, the order can be tracked using the Royal Mail Track your item service.

Happy testing!