# Help with homework-Transistor as battery charger

#### Jim Pap

Joined Nov 27, 2020
6
I have to find R1 and R2 so I can make Q1 work as a current source 10-100mA. Thanks
• β=100
• Vbe=0.6V
• Vcc=12V

#### Wolframore

Joined Jan 21, 2019
2,610
Do you know how to make it pass 10 mA with the given information?

#### crutschow

Joined Mar 14, 2008
34,392
Do you know what β represents?

We don't do homework here, but we will help you with it.

#### WBahn

Joined Mar 31, 2012
30,034
This is a REALLY bad circuit design, so just keep in mind that this is a highly-idealized paper-only exercise that is way oversimplified.

To start, replace the resistor and pot with a single resistor, call it Ro. What does the value of Ro need to be to a particular collector current.

#### Jim Pap

Joined Nov 27, 2020
6
I want to delete this

#### Jim Pap

Joined Nov 27, 2020
6
This is a REALLY bad circuit design, so just keep in mind that this is a highly-idealized paper-only exercise that is way oversimplified.

To start, replace the resistor and pot with a single resistor, call it Ro. What does the value of Ro need to be to a particular collector current.
Delete this thread i did it.Thanks

#### WBahn

Joined Mar 31, 2012
30,034
Delete this thread i did it.Thanks
Not how it works. When you post something here, it stays due to the archival nature of a forum. The whole point is that the problems one person struggles with and the help they receive from other members because a resource for future people to search and learn from.

#### crutschow

Joined Mar 14, 2008
34,392
Delete this thread i did it.Thanks
We would appreciate a reply on how you did it.