I am also attaching the potentiometer file this time. May be you can get better tuning option.

I think we already have potentiometer with very good tuning option (resolution):

Sir the current through R19 should be a DC signal, Right? (Please correct me if I am wrong).
Then why the current is in the form of pulses.

Correction: Signal is DC voltage with small 32 kHz pulsations on top.
After amplification by U3, these pulsations produce in R19 current with 270 uA amplitude.

Tuning potentiometers also do not help.

Potentiometers can not help, because every subcircuit is designed with errors.

Can you achieve this target by using given circuit diagram. 'Get DC signal (4 to 20mA) through load resistance by variation in differential capacitor'.

Even if circuit will well redesigned, it will not work properly, because current, consumes by circuit, should be about 3 mA (lower than 4 mA),
but now this current is about 10mA. So, range of measuring current may be 11...27mA, but not 4...20mA.
If minimal source voltage will 18V (24V-Vline_drop-Vload_drop),
then circuit should consume overall power not more then 18V*3mA=54mW, only!
Ask your designer about such possibility.

 

I think we already have potentiometer with very good tuning option (resolution):
View attachment 200926

Correction: Signal is DC voltage with small 32 kHz pulsations on top.
After amplification by U3, these pulsations produce in R19 current with 270 uA amplitude.

Potentiometers can not help, because every subcircuit is designed with errors.

Even if circuit will well redesigned, it will not work properly, because current, consumes by circuit, should be about 3 mA (lower than 4 mA),
but now this current is about 10mA. So, range of measuring current may be 11...27mA, but not 4...20mA.
If minimal source voltage will 18V (24V-Vline_drop-Vload_drop),
then circuit should consume overall power not more then 18V*3mA=54mW, only!
Ask your designer about such possibility.

But sir this is a pre-designed circuit(1153 Pressure Transmitter) and has already been used in industrial applications. I need to perform simulation for my project. The range can be an issue, but initially at least the change of differential capacitance should be sensed and propagated to the output. But there is no effect on the output current as a result of variation in differential capacitance.
Sir, one more thing, can you share with me your email ID or any other contact information only if you feel comfortable.

 

Sir, one more thing, can you share with me your email ID or any other contact information only if you feel comfortable.

Click on my avatar (photo), then click on "Start conversation" for private messages.

 

@irsarasheed
It works:

 

You are great sir, I knew you are an expert in this field. I'll have a look and contact you if I have any queries. Thank you sir. Stay blessed Always.

@irsarasheed
It works:

View attachment 201225

You are great sir, I knew you are an expert in this field. I'll have a look and contact you if I have any queries. Thank you sir. Stay blessed Always.

 

Sir, how to determine the effect of temperature on capacitors ,diode ,transistors and opamps. Like for resistors , I can write resistance value tc=xxppm. I want to apply temperature sweep analysis.(.step temp lower range upper range step size). But it should be precise and consider effect for each component. How can I look for effect of each component under high temperature?
Looking for your guidance.

 

Sir, how to determine the effect of temperature on capacitors ,diode ,transistors and opamps. Like for resistors , I can write resistance value tc=xxppm. I want to apply temperature sweep analysis.(.step temp lower range upper range step size). But it should be precise and consider effect for each component. How can I look for effect of each component under high temperature?
Looking for your guidance.

Read this article:
https://www.electronicspoint.com/forums/resources/managing-temperature-in-ltspice.18/

 

Okay sir thank you so much for your guidance.
sir, I read this article. and also watched this Youtube video. (The video also describes to add temperature coefficient for electrloytic capacitor resistance.)

I didn't find any information about the component characteristic except for resistance. This article also defines how to add temperature coefficient for resistance. For other elements, its same to define global or local temperature. If you know any other spice directives for other components (to be more precise in temperature sweep analysis) , Please let me know.

 

Sir your guidance for CR300 diode helped to adjust the output range of transmitter. Thank you so much sir for your affectionate response and guidance. I really find you most helping and expert in the field of circuit design.
Sir, I have another question. What does this connection represent ? How did you know that there should be a wire connection here.

 

Sir, I have another question. What does this connection represent ? How did you know that there should be a wire connection here.

Without this wire circuit does not work.
Diagram below is from your file Explanation.docx.

 

If you keep going as we are now, member Danko is going to graduate jointly with Irsa Rasheed, 50% each. Not a bad deal.

 

Without this wire circuit does not work.
Diagram below is from your file Explanation.docx.

View attachment 201571

Oh, THANK YOU SO MUCH SIR. You solved my problem like always.

 

Hi Sir, I hope you are doing well. I have another question. Is there a way to introduce faults in components in LTSPICE. The MULTISIM allows fault generation in each of its components. Please guide me.


http://zone.ni.com/reference/en-XX/help/375482B-01/multisim/settingplacedcomponentsfaults/#wp245032

 

Hi Sir, I hope you are doing well. I have another question. Is there a way to introduce faults in components in LTSPICE. The MULTISIM allows fault generation in each of its components. Please guide me.

Unfortunately LTSPICE has not such feature.
And models do not contain information about critical values of parameters.
ADDED:
@irsarasheed, pay attention to
how they are different:
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Model of BJT [Q1] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Real BJT [Q1, D2, D3] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

 

Unfortunately LTSPICE has not such feature.
And models do not contain information about critical values of parameters.
ADDED:
@irsarasheed, pay attention to
how they are different:
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Model of BJT [Q1] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Real BJT [Q1, D2, D3] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
View attachment 202681 View attachment 202682

Thank you so much for your information.

 

Thank you so much for your information.

I am really impressed by your knowledge and expertise of this field.

 

Danko sir, do you have thermitor model in LTSPICE?
I'll really appreciate your help.

 

Just like you shared your potentiometer model for resistor, please also share for thermistor? Do you thinking implementing thermistor resistor by this way is correct ?

 

Danko sir, do you have thermitor model in LTSPICE?

Hello irsarasheed,
You can use this method:

 

Thank you so much sir !!!