PIC Based Portable LCR Meter

The LCR meter project is based on dsPIC39F4012 microcontroller which can be used to analyze the analog performance of any analog device.

There are various techniques like direct digital synthesis (DDS) signal generation and digital signal processing (DSP) methods and algorithms that are being combined by the LCR meter to evaluate analog voltage and current signal properties where the LCD is used to display the information. Frequencies such as 100Hz, 1kHz, and 10kHz are implemented for testing while both parallel and series circuits are evaluated with more than 1% of basic accuracy.

During the process, a sine wave form of known frequency is generated by dsPIC LCR and applies it to the device under test (DUT) through a source resistance. Before being simultaneously acquired by the ADC module, the signals representing the current through and voltage across the DUT are conditioned and amplified. To reduce the influence of numerous error sources, the DSP filters further condition the acquired signals. The amplitude and phase can be calculated by accurately determining the zero crossings of the acquired waveforms.

The LCR meter system can automatically choose the most suitable frequency and circuit type for easy measurements.

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