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I've been working on a project where i'm building a h bridge motor circuit i have easily spent 15 hours on it and have made extremely slow progress on it in the last 3 days. The project sheet is seen below and i'm still on task 1 heavily struggling on the dc sweep of the inductor. [Task sheet 1

I will attach the circuit i have made on lt spice below

My circuit

Every time i do a dc sweep these are the errors ( attach below) i keep getting i have no idea how to fix them i have no idea if it is something to do with my circuit. Error message

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    \$\begingroup\$ Not only I don't see any .STEP command in there (you're saying you need to sweep the values for L), I don't see any .DC card, either (there is a .TRAN). That's why the errors you are showing in the error log have nothing to do with the picture of the schematic. To top all that, your schematic is so mingled, it's unreadable. There are many strange decisions in there so, rather than address them all, take a look at this answer for a reference on how to build your bridge. You can take it from there. \$\endgroup\$ Mar 15, 2021 at 7:33

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There are several issues with your schematic some are listed below. For U5 and U6 a voltage should be applied to pins Tcase and Tj equal to the temperature in Celsius (typically). The A1 inverter should have a statement that indicates high and low voltage. Things like back emf can be modeled with behavioral voltage source. https://www.precisionmicrodrives.com/content/ab-025-using-spice-to-model-dc-motors/ To sweep parameters like resistor and inductor, add variable name to value and enclose in brackets so ".step" spice command can be used. Consider the pmos and nmos selected as Vgs threshold and other parameters vary.

Below is incomplete example circuit which shows how to apply some of the syntax in LTspice Example Schematic

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    \$\begingroup\$ No need for diodes, the transistors have builtin, but since this is a test case you can use VCSW instead of MOSFETs (see the link in the comment). That way there's no need for vhigh in A1, the VCSW .model will take care of it. If you used parasitics, use them in full: add Cpar besides Rser in the sources, no need for external caps (and two in parallel is just visual). While you're at it, for a more convergent friendly way: no BV, no V_sense, instead add a CCCS across R1 with L1 {value/R_motor} (careful about the polarity). Also no need for Ncycles in V1. \$\endgroup\$ Mar 15, 2021 at 10:09
  • \$\begingroup\$ @LilPappz23 Then be sure to select the answer (the check mark), so that other people in the future, searching for similar problems, will see this question with an accepted answer. \$\endgroup\$ Mar 17, 2021 at 8:16

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