I have tried building a phase shift oscillator, but it won't work

[David lopez]

But I already have some experience
Making electronic circuit. For example
I worked with operational amplifiers, comparator, circuit that turn leds, built
555 timer circuit in both a astable mode and monostable mode, built circuit that charge a capacitor and discharge a capacitor, built analog to digital converter, built voltage dividers,
Built set- reset circuit, built d-type circuit, built solar powered circuit, have programmed arduino microcontroller, built circuit that turns on buzzer, worked with and gates, quad inverter ic, built no gate out of transistor and resistor, built circuit that turns on small electric motor, worked numeric displays, lcd drivers, pressure sensors and experiment with different arrangement of components. Then I thought I could learn a.c. circuits next.

 

[davenn]

But I already have some experience
Making electronic circuit. For example
I worked with operational amplifiers, comparator, circuit that turn leds, built
555 timer circuit in both a astable mode and monostable mode, built circuit that charge a capacitor and discharge a capacitor, built analog to digital converter, built voltage dividers,
Built set- reset circuit, built d-type circuit, built solar powered circuit, have programmed arduino microcontroller, built circuit that turns on buzzer, worked with and gates, quad inverter ic, built no gate out of transistor and resistor, built circuit that turns on small electric motor, worked numeric displays, lcd drivers, pressure sensors and experiment with different arrangement of components.

yeah, but how many of them did you actually get working ?

so far on the forum, you have come with 4 projects, none of which you have got working
even with the help that has been offered

 

[David lopez]

I got the ones I listed working, except the 4 projects I asked about. Those 4
Are the hard ones.

 

[Nik_2213]

IMHO, phase-shift oscillators can be very fussy beasts. My 'Discrete' versions sometimes failed to start, and even an op-amp's gain might not suffice to initiate oscillation. Akin to oscillator sims that just sit there until you stomp off for a coffee while iteration errors accrue...
Against that, I've had 'accidental' phase-shift oscillators that took patient de-bugging to tame...

OP, may I suggest you Google/Bing at least a dozen versions of your circuit, compare, contrast, calculate their nominal frequency, mutter 'Ah?' and 'Gotcha!' etc etc. IIRC, you'll find that function often requires RC values that are much more restricted than simple theory predicts. Go beyond the 'habitable zone' and, despite correct wiring, appropriate power supplies, loading etc, the circuit may simply not start.

Also, though I've seen some ingenious approaches in eg Graf's multi-volume 'Encyclopaedia of Electronic Circuits', you will be hard-pressed to 'swing' any phase-shift oscillator's working frequency across a significant range as-is. Switching Cs and varying the Rs 'in synch' with a 'dual linear potentiometer' is simplest approach, despite poor stability, non-linearity etc etc...

Given your difficulties to date, I'll not recommend DIY with an '8038' function generator IC.

Get a breadboard phase-shift oscillator working as 'proof of concept', document its quirks & foibles, then get a complete $20 mini-SigGen on-line. With that as a 'sanity check', you may then go back and explore...