IC LM741 as a Signal Generator:  The operational amplifier IC-741 is not only instrumentation amplifier, it can generate different type of the waveforms by charging and discharging mode. Function generator give waveforms such as sine, triangular, square waves and so on of different frequencies and amplitudes. Here is a simple circuit which generates square waves and triangular waves simultaneously.

Below the circuit 1st circuit is a square wave generator and second section is an integrator. This square wave is given as input to integrator it produces triangular wave.
Circuit for Function Generator Calculation: Square wave Generator:
T= 2RfC ln (2R2 +R1/ R1)
Assume R1 = 1.16 R2
Then T= 2RfC
C and find Rf
R1 and find R2.
Model Calculations:
For T= 2 m sec
T = 2 Rf C
Assuming C= 0.1μf
Rf = 2.10-3/ 2.01.10-6
= 10 KΩ
Assuming R1 = 100 K
R2 = 86 KΩ.
Change R & C Value of the 1st Op-Amp circuit we can get different output frequency wave which we want.
IMPORTANT: Before test this circuit Apply correct polarity of dual power supply, +12v to IC Pin-7, -12v to IC pin-4.