A safe way to obtain a sinusoidal signal of excellent quality and low frequency without the need to use LC resonant circuits is with the help of a Wien Bridge oscillator. The circuit shown in the figure generates signals in the range 150 to 1500 Hz with the components used. Capacitors C1 and C2 (which must be the same) determine this frequency range. The minimum value indicated for these capacitors is 10 nF when we have the upper limit of the generated frequency range, which is in the order of 15,000 Hz. At points X and Y, a symmetrical stabilizer network must be connected which determines the circuit gain and, therefore, its feedback so that saturation does not occur. The network can be any one of the three indicated, which, depending on the characteristics of the devices used, will influence the gain of the circuit. The power supply used in this oscillator must be symmetrical and the assembler must take care to connect the double potentiometer P1 so that the variation of the two sections occurs in the same way.
