sine wave & bubba oscillator

[maysara]

hi, this is my simulation for bubba oscillator sine wave generator but the output is nothing
can anyone tell me what is the mistake in the schismatic ?

simulation by multisim

 

[LvW]

Your dc operating point is not OK.
Are you required to use single supply only?
What is the purpose of Vcc=6V at the pos. input of the unit U2A ?
Determine the dc output of an opamp rather than measure the input.

 

[Audioguru]

You have the (+) input of the first opamp biased at the same voltage (+6V) as the power supply voltage so the outputs of all the opamps are saturated as high as they can go. Instead, bias it at half the supply voltage.

You have the value of R5 the same value as R6 so that it severely loads down R6. instead, the value of R5 should be MUCH higher than R6.

You are using an old-fashioned quad opamp that has a low input impedance, a low output swing and many other poor spec's. Use a modern one.

Look at this document about sinewave oscillators from Texas Instruments:

 

[maysara]

Re: sine wave & bubba oscillator

yes circuit required one supply
an Vcc this is my input

- - - Updated - - -

thanks Audioguru i am really benefited by your comment thanks a lot

- - - Updated - - -

what the name of some modern of opamp ic ?

 

[Audioguru]

Re: sine wave & bubba oscillator

what the name of some modern of opamp ic ?

My schematic from Texas Instruments shows their modern Cmos rail-to-rail TLV2474 quad opamp.

 

[maysara]

Re: sine wave & bubba oscillator

My schematic from Texas Instruments shows their modern Cmos rail-to-rail TLV2474 quad opamp.

thank you vary mach