In this note, we are going to know about LCR Meter, and its Working Principle, Block Diagram, and Applications as well. Welcome to Poly Notes Hub, a leading destination for Engineering Notes for Diploma and Degree Engineering Students.
Author Name: Arun Paul.
What is LCR Meter?
An LCR meter is an electrical device that measures inductance (L), capacitance (C), and resistance (R) in components. It uses an AC signal to detect a component’s impedance and phase angle, allowing it to calculate these values precisely. LCR meters are crucial tools in electronics for testing, quality control, and circuit analysis.
LCR Meter Working Principle
An LCR meter sends an AC signal to the component being tested and detects the voltage and current flowing through it. These measurements determine the component’s impedance, and the meter calculates and displays the corresponding inductance, capacitance, or resistance.
Basic LCR meters normally measure only one frequency, whereas more advanced meters support several test frequencies. By evaluating the phase angle between voltage and current, the meter can differentiate between reactive (inductive or capacitive) and resistive components, allowing for precise determination of the desired value.
LCR Meter Block Diagram
- Oscillator: It is generates an Alternating Current at a limited frequency (often 1 kHz) to apply to the component under test.
- AC Voltage Source: It is supplies the test signal to the component.
- Measurement Circuit:
- Voltage Measurement: It measures component voltage.
- Current Measurement: It measures the flowing current through the component.
- Phase Detector: It is used to determines the phase difference between the voltage and current, which helps identify if the component is inductive, capacitive, or purely resistive.
- Impedance Calculator: It is used to calculates the impedance (Z) based on the voltage and current measurements.
- Microcontroller/Processor: Used for processing the impedance data to derive inductance, capacitance, or resistance values and displays them.
- Display Unit: It shows the measured values on the digital display and LCD display.
Application of LCR Meter
Here are some uses of this meter Meter –
- Ensure that components fulfill design criteria prior to assembly in electronics production.
- Sorting inductors, capacitors, and resistors according to their precise values for use in circuits.
- Testing component behavior within circuits to ensure they work properly under various scenarios.
- Repairing electrical equipment by inspecting component integrity.
- Commonly used in laboratories for experimental verification and learning.