I am doing projects using arduino since 1 year. For my new project I am planning to make an impedance analyzer to analyze different components like sensors or solar cells. My plan here is to analyze the characteristics of a component over a given frequency range for eg 50Hz to 9000Hz. In other words I want to do a frequency sweep. But I am stuck here with the use of AC Voltage ans AC current. I know that ac current can damage my device. What I actually want is a way to give an AC input and get the output characteristics while at the same time run the frequency sweep loop.
Any help would be much appreciated!!
I don't think that you'll get useful results without additional analog circuitry. At least an DAC is required, which you feed from a sine lookup table for the waveform, with variable delay for the sweep. Also a rectifier will help to catch the amplitude, otherwise your ADC may miss the true min/max values. Eventually a zero-crossing detector should be added, if you are interested in the phase shift as well.
I'm not sure what AC voltages you have in mind, usually a few mV are used for such a device.
My plan is to make the device work at 10mv and at 1000 HZ of frequency. The additional circuitry that I am using is an ADC, a rectifier for DC input to arduino, a ceremic resonator and filter circuits for checking the impedance characteristics.
For proper analysis you need sine waves, not rectangles with many harmonic waves. I doubt that you can construct a low pass filter for the intended frequency range (50 to 9000Hz). A fast DAC may be usable to approximate a sine wave, but it still will produce harmonic waves. For a single frequency of 1kHz a fixed frequency sine wave generator/oscillator is okay, but it will produce only that frequency.