Your project is private, please make it public.

@immoos, Please see: [https://docs.easyeda.com/en/Simulation/Headings/index.html](https://docs.easyeda.com/en/Simulation/Headings/index.html) It might help you find the problem.

@immoos, If your circuit is similar to any of these: [https://easyeda.com/immoos](https://easyeda.com/immoos) then it will be difficult to simulate it in EasyEDA because there is no readily available Ngspice compatible spice model for the TL494. You may be able to simulate it in LTspice and - sometime in the future - be able to import the LTspice schematic and symbol into EasyEDA to add the PCB footprint and BOM information so you can then do the PCB layout.

Thanks Is it possible for my to try to make the spice model for the tl494.

@immoos, You may be able to hack one of the models referred to in these links: [https://forums.ni.com/t5/Multisim-and-Ultiboard/I-NEED-SUBCIRCUIT-MODEL-FOR-TL494-PWM-OSCILLATOR-AND-TC4421/m-p/522982](https://forums.ni.com/t5/Multisim-and-Ultiboard/I-NEED-SUBCIRCUIT-MODEL-FOR-TL494-PWM-OSCILLATOR-AND-TC4421/m-p/522982) Ideally you want to start from a 3f5 or Spice3 model and not from a Psice model because they have some model and syntax differences from Ngspice. This may help give some insight into how to make a model but it will not run in Ngspice without significant re-writing: [http://markkhusid\.ddns\.net/current\_projects/current\_projects\_electronics\_hacking\_TL494\_LTSpice\_model\.html](http://markkhusid.ddns.net/current_projects/current_projects_electronics_hacking_TL494_LTSpice_model.html)

@immoos, These datasheets will help you to understand how the device works internally: [http://www.onsemi.com/pub/Collateral/TL494-D.PDF](http://www.onsemi.com/pub/Collateral/TL494-D.PDF) [http://www.ti.com/lit/ds/symlink/tl494.pdf](http://www.ti.com/lit/ds/symlink/tl494.pdf) You may be able to model just the parts of it that you are using rather than try to model the whole device. There are all sorts of tricks you can use to simplify the model. It depends on how accurately you want your simulation to be and, of course, how much experience you have of developing spice models. :)