The circuit shown in figure 1 is suggested by Texas Instruments and is based on its JFET TL071 operational amplifier, generating rectangular 0,5 Hz signals .
Other amplifiers of the same series can be used as the TL081, TL072, TL082, etc. in the same configuration. The value of C can be modified to generate other frequencies, according to the formula given in the diagram.
The power must be supplied with a symmetrical 15 V supply. In figure 2 we have a suggestion of printed circuit board for implementation of this oscillator.
Material list
CI-1 - TL071 - Operational Amplifier
R - 100 k ohm x 1/8 W - resistor - see text
C - 3.3 uF - capacitor - see text
R1, R2 - 3.3 k ohm x 1/8 W - resistors
R3 - 1 k ohm x 1/8 W - resistor
R4 - 100 ohm x 1/8 W - resistor
More:
Symmetrical power supply, printed circuit board, wires, solder, etc.
