FM-Tuner (TDA1062)

Using almost any operational amplifier it is possible to build a simple and reliable squarewave oscillator. The design is free from latch-up problems sometimes experienced with conventional multivibrators, the frequency is independent of supply voltage and the circuit uses only six components. Operation of the circuit is as follows: at switch-on C I is discharged. The inverting input of IC I is thus at zero volts while the non-inverting input is held positive by R I and R2.