# Buck converter control malfunction **URL:** \ **Category:** PLECS\ **Tags:** buck-converter, application-example\ **Created:** [September 24, 2021, 12:05pm UTC](https://forum.plexim.com/t/buck-converter-control-malfunction/1061 "2021-09-24T12:05:34Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![AliAbdelrahman](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@AliAbdelrahman](https://forum.plexim.com/u/AliAbdelrahman)\ **Post date:** [September 24, 2021, 12:05pm UTC](https://forum.plexim.com/t/buck-converter-control-malfunction/1061/1 "2021-09-24T12:05:34Z")
Hi, I am trying to control a buck converter, I implemented voltage control method and designed it on paper first, checked the TF via matlab and everything seems accurate till now. Now I try to simulate toe boost and the output voltage is the same as the input voltage and I am really puzzled, I checked the buck analog control demo and copy pasted some stuff from there and still I get the same output. I am thinking maybe the issue is from the op amp circuit, but I dont know how to navigate that. thanks 🙂 I attached the schematic, the output from the scope and the project. ![BUCK cntr.png](https://europe1.discourse-cdn.com/flex006/uploads/plecs/original/1X/15a4bcfac8fc875e0486d532181f30c0f0b817a5.png) ![Buck cntrl 2.png](https://europe1.discourse-cdn.com/flex006/uploads/plecs/original/1X/2795690780b5475af1a27a90116d95e0a219b26d.png) [First control project.plecs](https://forum.plexim.com/uploads/short-url/kX69BdfIwD5uC5tl28sf0pY46VI.plecs) (23 KB) ---
**Author:** ![Sivakumar\_Gannamraju](https://avatars.discourse-cdn.com/v4/letter/s/49beb7/32.png) [@Sivakumar\_Gannamraju](https://forum.plexim.com/u/Sivakumar_Gannamraju)\ **Post date:** [February 8, 2024, 4:28am UTC](https://forum.plexim.com/t/buck-converter-control-malfunction/1061/2 "2024-02-08T04:28:31Z")
One point I could see is that the op amp power supply is not connected to ground. Could you please explain more about why you are adding some constant to modulating signal?