# Tl494 based power supply is good to diy or not.

#### rahul411

Joined Feb 19, 2018
260
I saw this video on adjustable power supply and i i iave everything that need to build it. But i want to know whether it is good design or not. Although the author has described everything in the video but there is some questions in my mind when she's testing the power supply. Check yourself the testing part. What you guys think of it.
Circuit diagram is attached below.

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#### Bordodynov

Joined May 20, 2015
2,697
I think it's a diversion in this design. Look at the combination of R7 and R9 resistors. The combination of these resistors reduces the control voltage at the gates by a factor of about 6. If there is something going to work with a 30 V supply (control voltage of opening the transistors is ~5V), there is no such thing with less. You can simulate this scheme and fix it (possibly) with LTspice (together with my model collection). I simulated a similar circuit (somewhat more complex) with a minimum output voltage of "0".

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#### rahul411

Joined Feb 19, 2018
260
I think it's a diversion in this design. Look at the combination of R7 and R9 resistors. The combination of these resistors reduces the control voltage at the gates by a factor of about 6. If there is something going to work with a 30 V supply (control voltage of opening the transistors is ~5V), there is no such thing with less. You can simulate this scheme and fix it (possibly) with LTspice (together with my model collection). I simulated a similar circuit (somewhat more complex) with a minimum output voltage of "0".View attachment 184500
Where can i find the spice model for tl494? On GitHub there is .sub file. I have your ltspice model collection though but it does not contain tl494

#### Bordodynov

Joined May 20, 2015
2,697

#### rahul411

Joined Feb 19, 2018
260

#### Dodgydave

Joined Jun 22, 2012
9,651
The circuit is using a single output paralleling the outputs to form a single pulsed smps, it's a good design utilising both internal OP amps for voltage and current control. Pin 13 is the single/complimentary control.

The TL494 is the easiest and in my opinion the best versatile smps controller to use.

#### rahul411

Joined Feb 19, 2018
260
The circuit is using a single output paralleling the outputs to form a single pulsed smps, it's a good design utilising both internal OP amps for voltage and current control. Pin 13 is the single/complimentary control.

The TL494 is the easiest and in my opinion the best versatile smps controller to use.

View attachment 184522
Why there's no transformer?

#### Dodgydave

Joined Jun 22, 2012
9,651
Why there's no transformer?
There is an Inductor for a single output with Shotkley diodes for bemf recovery.