Calculating Resistance for Charging a Battery Circuit Using Ohm's Law

[dancergirlie]

Homework Statement

Make a modification so that the battery is charged by the DC supply at a current of 10mA

**See attached diagram**

Homework Equations

The Attempt at a Solution

Well I know that I would put in a resistor in parallel with the diode. However, I don't know how I would solve for the resistance.

I'm assuming that I would use Ohm's law:

V=IR where I=10mA, and I don't know what the voltage drop across the resistor would be... would it be 3V so that the battery drops 12 volts?

Any help would be great!

 

[berkeman]

Homework Statement

Make a modification so that the battery is charged by the DC supply at a current of 10mA

**See attached diagram**

Homework Equations

The Attempt at a Solution

Well I know that I would put in a resistor in parallel with the diode. However, I don't know how I would solve for the resistance.

I'm assuming that I would use Ohm's law:

V=IR where I=10mA, and I don't know what the voltage drop across the resistor would be... would it be 3V so that the battery drops 12 volts?

Any help would be great!

Yes, that is correct.

 

[dancergirlie]

thanks for confirming :D