rc oscillator

[joconno]

Hello,

I have tried to simulate an 3 stage RC oscillator, with the correct gain to start oscillating, but to no avail.

I've attached the simulation, does anyone know where i've gone wrong?

many thanks

john

[Mahmoud_W]

Hi John,

According to the oscillation condition the value of R4 in your circuit should be less than 8.4kOhms.

Please review that and set R4 to a value less than this number and it should work.

Good luck,

Mahmoud W

National Instruments

[joconno]

Hi Mahmoud,

Many thanks for your help, it does work after I changed R4 to 8k.

I thought that R5 should be 29 times the value of R4?

If possible could you explain the theory behind your choice of R4?

Thanks again

John

[iesdaluver]

may i asking something. where do you get the R4 is 8.4k. as i know. R1 must be 10R. can u show me the calculation. here i attach my circuit. i cant get my wave