Wien oscillator circuit is in my opinion one of the oscillator circuit is quite simple. Only by using a single Op-Amp IC and some resistors and capacitors and two diodes. You can use a 5 volt zener diode to the second zener diode above. So you can make it as a pilot project, add a collection of calculated electronic circuit inside the head.
To be honest I did not design its own oscillator circuit mentioned above. I only get the circuit from a sample circuit electronics software. Above wien oscillator circuit using IC op-amp as a component of a bridge builder. Basically the above oscillator circuit is inseparable from the nature of the strengthening of the op-amp circuits in general. Only use the charging and discharging capacitor properties as the creator of the condition of the signal swing. Take a look at the positive input of op-amp, the input signal is obtained by dividing the voltage between the series resonant circuit RC and parallel RC. Where this is the generation process of the circuit in the form of a sinusoidal signal (you can see the working principle of the LC resonant circuit).
To find the value of the frequency of the circuit above you can use the formula is 2 * pi * R * C. Where in the circuit above R = 20kohm and C = 10nF. Zener diode is mounted upside down in pairs so that the resulting signal serves as a signal box but not sinusoidal signal is perfect. You can just change the supply voltage to 9V-9V & if you do not have a 15 V supply, but the resulting output signal will have a maximum voltage of 9 volts.
