Hello, I'm building an Smps using tl494 chip for a stepper motor and I got 36 or 37 volts dc from the secondary filter capacitor. I want to regulate it at 36.00v. I've followed the diagram shown below from the datasheet. I've changed the resistor values from what's available to me. I've used 4.7k ohm for R3, 10k pot for R4, 67k resistor for R8, 5k for R8, 470 ohm for R5, 47k for RF.
The voltage regulation is not happening. I'm also confused about the ground pin which is connected to R9, is it the same ground pin connected to pin 7 of the tl494? If not what is the relationship between the two grounds? How can I successfully regulate the voltage if Vo is referenced from the secondary ground?
I'm using half bridge topology with center tapped secondary. I've tried the output dc with a stepper motor and it perfectly drives the stepper without an issue. I just wanted to get a stable voltage.

 

You have 36 to 37 volts and you want to get 36 volts out. The circuit you present needs at least 4 volts drop. 36 in 30 out. Even that is hard for this circuit.
It looks like you have a 10A load. Do you need the current limit?
What you need is a LDO regulator. Low Drop Out

 

To get 36V out from 32V in (as shown on your schematic) you need a boost regulator. Your circuit is for a buck regulator.

 

I only followed the error amplifier wiring from that circuit. My circuit is as shown here. Can you tell me about the primary and secondary ground? Do they need to be connected? If not, won't it affect the voltage regulation? Because from which ground is the voltage feedback referenced?

To get 36V out from 32V in (as shown on your schematic) you need a boost regulator. Your circuit is for a buck regulator.

 

I only followed the error amplifier wiring from that circuit. My circuit is as shown here. Can you tell me about the primary and secondary ground? Do they need to be connected? If not, won't it affect the voltage regulation? Because from which ground is the voltage feedback referenced?

When I say the primary ground I'm referring to the tl494 ground pin (pin 7).

 

Can you tell me about the primary and secondary ground? Do they need to be connected?

Yes

 

What is the output load current?

 

I got 36 or 37 volts dc from the secondary filter capacitor. I want to regulate it at 36.00v.

Why regulate 37 volts to 36 volts? Is the stepper motor that picky? I think a 36V motor will work on 36 to 37 just fine.

 

What is the output load current?

I'm driving 4.2amps stepper with it.

 

Why do you think you need a regulator?