Re: function generator
Generating a sine wave is a function, so is generating a square wave. Simple function generators generate at least sine, triangular and square waves,both of the last two with a 50% duty cycle ... which means that in the square wave case the 'mark' is the same length as the space. More complex function generators allow us the change the duty cycle for square waves between 0 - 100%. We mainly need this for digital circuits. They also allow the 'ramp ration to be chnges on triangular wave forms. The conventional triangular wave has a 50% duty cycle. More advanced function generators allow this to be changed between 0 -100 %. So we are in effect altering the slop of the wave. At the extreme ends the waveform looks like a saw tooth.
With function generators we get what we pay for in terms of performance, accuracy, distortion etc. For beginners a very simple generator is required. It will probably have a frequency range of between 10 Hz - 100 kHz. Even a 1 Hz to 1 mHz generator is still fairly simple. A more professional version may operate from 0.001 Hz up to about 20 mHz, but a beginner would not need one of those. It helps if the function generator has a calibrated output control or attenuator. Most people tend to monitor the signals generated on an oscilloscope. Function generators are not difficult to make and would be a good project.