I was wondering if there is a way to change parameters of NSCW100 LED in LTSPice? I like the Vf of 3.5 but would like a max current 180mA for the LED instead of 80mA I believe.

 

Hi Guy,
Welcome to AAC.
In the LTSpice folders, find Cmp folder, then open the standard.dio file in a text editor.
All diodes are listed.
Make a copy of the NSCW text group, rename it, then change the mA value and Save the standard.dio
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model NSCW100 D(Is=16.88n Rs=8.163 N=9.626 Cjo=42p Xti=200 Iave=30m Vpk=5 mfg=Nichia type=LED)

 

I was wondering if there is a way to change parameters of NSCW100 LED in LTSPice? I like the Vf of 3.5 but would like a max current 180mA for the LED instead of 80mA I believe.

One I/V value does not and LED make...
The usual practice is to find the LED datasheet for the LED you intend to use and match the If-Vf curve.

 

One I/V value does not and LED make...
The usual practice is to find the LED datasheet for the LED you intend to use and match the If-Vf curve.

Ya you are right, looking at it now I also got the wrong Vf was thinking of another LED that I looked at. Probably need something more like the picture

 

.Model LED D (IS=9.99891e-15 N=3.57239 RS=1.55125 BV=5 IBV=10u CJO=40p)

 

Was wondering about a DC sweep of the attached circuit to take the current flow and voltage node readings. The source is regulated at 29.5V and the CCR is driving the LEDs at 97mA.

 

Was wondering if I also have the string set up correctly? Need to see the Vf at the bottom node. Thanks

 

Hi Guy,
Please post your asc file
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Update:
You can simplify the number of LED's by using the n=7 option, set the n value to suit your number of LED's

 

Here is the file, thanks

 

I updated the file to be closer to what you have, how did you model the pulse Thanks

 

Hi guy,
What are you trying to measure with this simulation?
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Hi guy,
What are you trying to measure with this simulation?
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current flow and voltage node readings, along with the drop of voltage possibly as it goes down the string. This is from a power supply that is 29.5Volts. The CCR is set to 97mA which I just used a source since the ORCAD model of IS32LT3177 just kept crashing.

 

Hi guy,
Try this sim.
Note I have changed the LED's name.
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Hi guy,
This may help.
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Added: asc file

 

Was wondering if I also have the string set up correctly? Need to see the Vf at the bottom node. Thanks

You can configure it as post #8 but replace R1 with a current source of 97m.
This won't show the behavior of a CCR but will allow you measure the value across the last LED.

 

Thanks a lot everyone

 

I have a model for the CCR I am using but have trouble opening it do to some directory issues, how do I solve this issue? Thanks

 

hi guy,
Please post the model
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Here you go, just seeing if I get different results with the IC model. Thanks

 

Hi,
You have encrypted the rar.!
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