How to change Bf in the 2N3904 transistor model

[bpenfold]

Hello,

It’s very confusing but can someone show me how to change the “Bf=416.4” in the

2N3904 transistor? The Help utility is not clear. I follow the Help but when I double check the part, the parameter never got changed.  I need to see what happens when I make Bf=40.

Thank you,

-Barry

[yyao]

Hi Barry,

This is quite easy to do. Try this:

1. Place a 2N3904
2. Double click on the transistor on the schematic. A dialog box should appear
3. Click on the Value tab of this dialog
4. Click the Edit model button. This will bring up the dialog which lets you edit the SPICE model for this transistor.
5. Change the first line so that Bf=40
6. Click Change part model
7. Click OK
8. Rerun your simulation. Your transistor should behave differently now.

Hope that helped.

[Albeiro]

Hello, my name is Albeiro.

I need help with the change beta of transistor. When i change beta of any model of transistor, for example i changed transistor beta of tip41c to 390, but when i use it in the circuit, it have a beta of 172. Can you help me with this problem?