Question

A student wants to use the output from the aux port on their phone to play music from their speakers. The aux port supplies 5v and a max current of 0.015A, but the speakers need 12v and a max current of 1.5A. You decide to use a power transistor to amplify the signal from the aux port. What does the beta value of your chosen transistor need to be to amplify the current enough?

pls explain or elaborate the answer if u can!!

Answer 1

Answer:The beta value of a transistor represents the current gain, which is the ratio of the collector current to the base current. In this case, we want to use the transistor as an amplifier to increase the current from the 0.015A supplied by the phone to the 1.5A required by the speakers.

The required current gain can be calculated using the following formula:

Beta = (Ic / Ib)

Where:

Beta is the current gain of the transistor

Ic is the collector current (output current)

Ib is the base current (input current)

To find the required beta value, we need to first calculate the base current required to drive the transistor. We can use Ohm's Law to do this:

Ib = V / R

Where:

Ib is the base current

V is the voltage supplied by the phone (5V)

R is the input resistance of the transistor circuit

Assuming an input resistance of 1kΩ, the base current required is:

Ib = V / R = 5 / 1000 = 0.005A (5mA)

Now, we can calculate the required collector current using the maximum current required by the speakers:

Ic = 1.5A

Finally, we can calculate the required beta value:

Beta = Ic / Ib = 1.5 / 0.005 = 300

Therefore, we need to choose a power transistor with a beta value of at least 300 to amplify the current from the aux port enough to drive the speakers.

Step-by-step explanation: