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Circuit not simulating buck converter

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RITESH KAKKAR

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Pick a MOSFET type, the generic device can give strange results.
Label your nodes so we know what we are looking at (as shown in the video).
Post your .asc file (as a .txt file if necessary).
 

...and select appropriate scale for probing the output; Your "gate driver" generate a square wave with 25us Ton time, hence computing simulation from T=0us to 500us but the graph displays result up to 5,000us ( 5ms ).

- - - Updated - - -

It is not clear if the V1 reference is really connected to the GND.
I would expect an error message from simulator.
 

Pick a MOSFET type, the generic device can give strange results.
Label your nodes so we know what we are looking at (as shown in the video).
Post your .asc file (as a .txt file if necessary).
Click to expand...
...and select appropriate scale for probing the output; Your "gate driver" generate a square wave with 25us Ton time, hence computing simulation from T=0us to 500us but the graph displays result up to 5,000us ( 5ms ).

- - - Updated - - -

It is not clear if the V1 reference is really connected to the GND.
I would expect an error message from simulator.
Click to expand...

OK,i am sending file have
 

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You did withhold that the simulation shows errors. It's due to incorrect parameter statements. (blue text in post#1).

You are writing text comments "pram" instead of Spice directives ".param". Please correct.

crutschow advised you to use a real transistor model instead of the generic NMOS type.
 
OK, sir i have done it.

it is showing transient output with 12V not 5V why?

showing error
Questionable use of curly braces in "v2 n002 n001 pulse(0 12 0 1n 1n {d*ts} {ts} 50)"
Error: undefined symbol in: "[d]*ts"
Questionable use of curly braces in "v2 n002 n001 pulse(0 12 0 1n 1n (d*ts) {ts} 50)"
Error: undefined symbol in: "[ts]"
Circuit: * C:\Program Files (x86)\LTC\LTspiceIV\buck.asc

Error on line 8 : v2 n002 n001 pulse(0 12 0 1n 1n (d*ts) (ts) 50)
Unknown parameter "d*ts"
Direct Newton iteration for .op point succeeded.

Date: Fri Jun 24 13:22:06 2016
Total elapsed time: 0.118 seconds.
Click to expand...
tnom = 27
temp = 27
method = modified trap
totiter = 2714
traniter = 2709
tranpoints = 1226
accept = 1184
rejected = 42
matrix size = 11
fillins = 4
solver = Normal
Matrix Compiler1: 754 bytes object code size 0.3/0.3/[0.2]
Matrix Compiler2: off [0.2]/0.3/0.4
 

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Here's is your circuit working.
I changed pram to .param and made it a Spice directive, not a comment (which is ignored by the program).
I used a real transistor model, not the generic for M1, as I previously suggested you do.
The output settles to about 5.6V.
It does not go th the theoretical 6V for a 50% duty-cycle due to loses in M1.

Buck.PNG

View attachment buck2.txt
 
made it a Spice directive, not a comment (which is ignored by the program).
Click to expand...

Hello,
What is spice directory and while simulation the heading was showing newton rapson formula something like that which i studied in CBNST what is the use of it?
 

RITESH KAKKAR said:
made it a Spice directive, not a comment (which is ignored by the program).
Click to expand...
What is spice directory and while simulation the heading was showing newton rapson formula something like that which i studied in CBNST what is the use of it?
Click to expand...

directive ≠ directory

I seriously recommend that you study a bit more the syntax and functionalities of this tool before proceeding with your simulation
 

how to remove transient error at starting
Click to expand...
Which transient error? crutschow's simulation has no transient error, mine neither.

You didn't yet post a valid simulation file, don't know which circuit are you simulating right now?
 

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