This project will explain how to build a very accurate and simple inductance,and capacitance measuring tool. You will also find information about the theory and math behind the measurements. The author did develop the hardware around the oscillator and a new working software, which would measure frequencies and take all the theory into consideration.
Specification of this LC-meter
0 nH to 10mH, resolution 2nH
0 pF to 10uF, resolution 0.1pF
1% of reading typical
Automatically calibration built in
2 line 16 white chars, blue backlight display
Automatic prefix pF, nF, uF, nH, uH, mH
Easy to learn and to handle
Testing program built in
Easy to build and to test
The main part of this project is a LCD, PIC16F870 and an oscillator LM311.The LCD is a standard 2 line 16 chars display connected in 4-wire mode to the PIC. At the bottom you will find a 4.000 MHz crystal to run the PIC.
The hart of this construction is the LC oscillator based around IC2. The frequency pops out at pin 7 and then enter the PIC at pin 11.Two relays have been added to make the measurement more automatic, and they will also prevent stray inductance/capacitance.Many LC constructions use manually switches which will be conected with long wires.
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