How to simulate a circuit consist of transistors in labview?

[leo321]

Dear friends,

Hi there!

I am new to labview and for now I need to build a circuit with transistors, TFT better, and then I will test the circuit with the code I built in labview. Could you please give me some advice on how to simulate a circuit consist of transistors in labview?

Thanks a lot!

Jason

[GerdW]

Hi leo,

do you really want to use LabVIEW to simulate an electronics sketch?

Why don't you use software like SPICE?

(The generic answer to your question is: get all the formulas you need to simulate your circuit, then implement them in LabVIEW…)

I will test the circuit with the code I built in labview.

This is something (completely) different then to simulate that circuit using LabVIEW…

[leo321]

Hi GerdW,

Thank you very much for your quick reply!

I am working on building a controlling and testing system with LabVIEW. Part of the design is as follows:

Using PCI-6221. I need 8 digital inputs and 8 digital outputs.

I try to achieve the function similar to active matrix (4*4 matrix, each row got 4 pixels):

1.With the scan driver 1, I hope to scan and open row 1, row 2, row 3, row 4 and then again from row 1...the other rows will close except the scanning one, the timing1 should be adjustable;

2.With the data driver, I hope to generate 4 bit digital data (each pixel should have 16 levels of voltage) to each pixel of the open row with reference voltage from outside.The time period should be synchronized with scan 1 and include it（larger than the scan driver 1）

3.With the scan driver 2 which is used to measure voltage. Because the scan driver 2 is used to measure, I hope it can be used anytime I need it.

8 voltage outputs will turn into digits through ADC on breadboard and then send to labview.

4.Each pixel will contain transistors and I need to test the signal from each pixel. 4 bit digital input means each pixel will have 16 levels of signals. So I need to make the whole picture in one system, could your please give me some advice? Many thanks!

[ram301090]

Hi

As Gred said, you can build equivalent mathematical equation for the circuit in NI LabVIEW or try some spice tools like Multisim, PSpice etc.

[leo321]

Hi ram301090,

Thank you very much for your advice!

1. Since I am new to LabVIEW, could your show me the steps on how to build equivalent mathematical equation for the circuit?

2. Which one should I use Multisim or PSpice if I just want to measure the different output signals from the circuits with transistors with labview's controlling?

Thanks a lot!

Jason

[GerdW]

Hi Leo,

1. Since I am new to LabVIEW, could your show me the steps on how to build equivalent mathematical equation for the circuit?

- Start LabVIEW.

- Open a new VI using Ctrl-N.

- Bring the block diagram window to front.

- Right-click into the white area and go to the Mathematics function palette…

I guess you know those equations - or you know atleast, which literature to read to learn them!

2. Which one should I use Multisim or PSpice if I just want to measure the different output signals from the circuits with transistors with labview's controlling?

Again: simulating a circuit (as you requested) is something completely different than measuring signals from a real device.

Use SPICE/Multisim to simulate your circuit. Use LabVIEW with some DAQ devices to measure real-world signals.

[leo321]

Hi GerdW,

Thank you very much for your reply!

Have you seen my second reply? I understand your point but what I really need to understand is as follows:

I need to build 4*4 matrix and each pixel will have 2^4=16 levels of signal to send back and measure in labview. The tricky problem is I don't have transistors (TFTs) in hand and all I got are PCI-6221 and labview, meanwhile I need to know whether my code to write digital data to every single row in the matrix is successful because the data will write row by row while the scan driver open each row.

I will be very grateful if you can give me some advice for this purpose. Thanks again!

Jason

[GerdW]

Hi leo,

when you want to test your program in controlling your hardware you could take a 2nd unit of that hardware. Or you build an extra PCB with the needed electronics and maybe some LEDs to visualize your scanning and switching…

[leo321]

Hi GerdW,

Thanks for your kind advice and time! I am very grateful for your time!

1.I have already finished the scanning part with leds on breadboard to show out. On the other hand, as to the data driver, while as your know 16 levels of signals in each pixel to be controlled by the front user panel which means user can change the digital data of each pixel anytime they want, how can I visualize this part? I am a little confused.

2.Could you please teach me how to synchronize the data driver and scan1 for timing control?

Thank you very much!

Jason

[GerdW]

Hi Jason,

how can I visualize this part?

You could dim your LEDs to different brightness…

2.Could you please teach me how to synchronize the data driver and scan1 for timing control?

What about using a state machine?

With states like "set scan1", followed by "set data", followed by "get scan2 results"?

Some general advice: before even starting to write any code in any programming language you should draw your algorithm on a sheet of paper. Right then you can already implement your requirements (as you have listed in your 2nd post). Once you are clear about the algorithm/structure of your program you can start to implement it in the language of your choice…