Design Ideal Transistor for Analysis

[Faheem Yar]

How to Change transistors parameter like beta and forward bias base-emitter junction potential in Multisim 10?

For example; Beta DC to 150 and forward junction potential to 0.7 volt. (Rest all Ideal Parameters) 

[Gilberto_Metzker]

Hi!

I have the same necessity about set up the parameters of one transistor, mainly the voltage base-emiter. Someone knows the SPICE parameters and the relationship between them that I can set up a precise voltage VBE in Multisim?

Thank's

Gilberto Metzker

[_user32]

Faheem Yar,

Ideal transistor can be represented several ways in Multisim, such as a current controlled current source for a simplified small signal AC response.   However the built-in Gummel-Poon transistor model (BJT_NPN_VIRTUAL) is well documented with characteristic equations in our Multisim Component Reference Guide.

http://www.ni.com/pdf/manuals/374485a.pdf 

Please give this a look to see if this provides you with the information you will need.  Chapter 4 covers the Bipolar Transistor models.

Regards,

Patrick Noonan
Business Development Manager
National Instruments - Electronics Workbench Group
50 Market St. 1-A
S. Portland, ME 04106
Email: patrick.noonan@ni.com
Tel. (207) 892-9130
Fax. (512) 683-7754 

[Faheem Yar]

Thanks for the reply.

I'm referring to the one the problem taken from Electronic Devices by Thomas L. Floyd. I want to simulate the circuit and produce the same theoratical results as shown in the following example. I couldn't seem to make an Ideal Transistor Model which could produce following results as shown in the picture.

Awaiting for Your Response.

Secondly, The symbol present in MultiSim 10 for Photo Diode is different than the one mentioned in the Electronic Devices Book by Thomas L. Floyd. Is it a mistake or is there something else to it? I mean the direction of arrows pointing towards/away from the Diode are different to the one present in the Book.

 Took Notice of this thing while designing an OptoCoupler. Still i can't seem to make an optocoupler using MultiSim 10. Help regarding this would be greatly appreciated.

Thanks.

Faheem Yar Khan

[Gilberto_Metzker]

Good!

I alread read the Multisim Component Reference Guide about the transistor (Chapter 4) and don't solve my problem too. The example of Faheem Yar is exactly that I want. This necessity is present in a class, where I need to solve a theoretician problem that I find in a book.

I'm anxious to solve it.

Thank's

Gilberto 

[JMGG2711]

Hi,

I made something that can help.

Attached you will find one of the examples that is in the book Electronic Devices and Circuit Theory of Boylestad and you can download from the companion website from pearson eduation, I made just the RE model for the BJT to compare the model simulation with the spice model of a BJT. Attached you will find one sheet that includes both circuits.

I did not get the same results but are similars.

Regards

Juan Gutierrez

[proglabview]

Si haces la simulación con Multisin con 2N222, obtienes:

I b = 0.429767  mA,   I c = 31.744 mA ,                    I e = 32.174 mA

Vbe = 0.703 V                        Vcb = 6.122 V            Vcb = 6.826 V

La diferencia entre el ejercicio y la simulación, esla Beta en el ejercicio se usa Beta = 150 y el simulador Beta = 73.97 y esto lo obtuve con        I c = Beta * I b ,          Beta = Ic / Ib

Este es un valor interno que maneja Multisim

++++++++++++++++++++++++

Práctico. Armando el circuito con un 2N2222 que se compra en Steren

 I b = 0.44mA

I c = 25.6 mA

I e = 25.6 mA

Vbe = 0.69 V

Vce = 7.16 V

Vcb = 6.46 V

Beta=  58.18