PIC LC-meter

LCmeter finished

Here is the description of a simple capacitance and inductance meter, easy to build, based around a PIC microcontroler. Simplicity does not mean poor characteristics. The precision is very good and even better than many commercial LCmeter !

The original description has been done by Phil Rice VK3BHR on his pages. I only did adapt it to my needs.

Here are the main characteristics :

  • measures from 0 to 838 nF and 0 to 83.88mH.
  • precision +/- 1%
  • printed board eliminating any connecting wires.
  • use of common case (at least here in Europe).
  • use of common components.

2 tone generator

2tone goodThe orinality of this description is that the tone generation is made by the use of a DDS and not a sine wave generator made with transistors or a special circuit. It also does not use any special and expensive component but only junk box components, or at least cheap ones !

The main characteristics of this generator are :

- Two tone generator 800/ 1000 Hz or 400/2600 Hz (jumper selectable)
- Single tone generator of 1000 Hz
- Ajustable output level, max around 100 mV pp on 600 Ohm, or 35,4 mV eff. in single tone or 25,0 mV eff. in 2 tones
- Spectral purity between 0,3 and 150 kHz > 50dB !
- Distorsion <0,01% (in single tone) !
- Supplied by a 9V battery, consumption 7-8 mA that gives 50 working hours with an alcaline battery.
- Automatic PTT switching at power on.

This circuit has originaly been described by DH7AHN ,adapted and translated by myself for my usage. The original description can be found here


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