Current and Voltage Limits

Status
Not open for further replies.
S

skill34

Newbie level 1
Joined
Feb 25, 2005
Messages
1
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,288
Can anyone help me with this problem?:

What is the minimum value of R in the circuit(description is forthcoming) if the maximum op amp output curent is 5mA and the current gain of the transistor is βf>50?

Circuit Description:

Inverting op amp in series with npn transistor who is in parallel with a resistor "R".

collector voltage=+25V
 

Are you sure the circuit is drawn correctly?

doesn't match ur description.
 

    S

    skill34

    Points: 2
    Helpful Answer Positive Rating
If you use lets say 40 ohm res then:
10V/40 ohm= 0.25A (Ibmax=5mA then Ie=5mA*50=0.25A)
power Dissipation on Q will be 0.25A*15V=3.75W
 

    S

    skill34

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…