Suggest me a high power BJT transistor

[aisd]

I'm using a push-pull stage with feedback as output stage of a devise, about 20-50 watts of power
so, i need power transistors that thier power limits are high. Actually, I dont want my transistors to melt down!
any suggestion about the model of them, plz?!

 

[alexan_e]

Re: Power bjt transistor

What is your voltage requirement for the transistors?

Alex

 

[aisd]

Re: Power bjt transistor

What is your voltage requirement for the transistors?

Alex

voltage requirement?!
:?:
sorry, but i dont get it!... what is a voltage requirement for a transistor?

 

[alexan_e]

Re: Power bjt transistor

What is the operating max VCE of the transistor you need, is it a low voltage application.
You only specified the watts you need, this can be a high current transistor with a low VCE voltage
or a high VCE with low current.

Alex

 

[aisd]

Re: Power bjt transistor

this is my circuit

the input (vs3) has max amplitude of 10V, and +V Supply (vpos) is +12 and -V Supply (vneg) is -12.
the resistant is 10 ohms at minimum

 

[alexan_e]

Re: Power bjt transistor

You could use 2N3055/2N2955 which are common transistors and you can find the easily.
Rated Ic=15A P=115W
2N3055 Datasheet pdf - COMPLEMENTARY SILICON POWER TRANSISTORS - ST Microelectronics
Check if the hfe suits you.

Alex

 

[FvM]

Re: Power bjt transistor

the input (vs3) has max amplitude of 10V, and +V Supply (vpos) is +12 and -V Supply (vneg) is -12.
the resistant is 10 ohms at minimum

So the power is lower than previously stated. Maximum power dissipation of each transistor occurs at Vsupply/2 output voltage, it's 12*12(4*10) = 3.6W, maximum current is 1.2 A. You can use smaller transistors than 2N3055, e.g. BD239/BD240.