Find solution
When is the max power event?

Max power transfer?

  • The concept applied here is fundamentally the same problem whether I am worried about hooking up a speaker to my power amplifier or connecting up a solar cell to an electrical load. For this problem assume that Vs = 12 V and Rint = 8 ohms. Assuming we are at the conditions for max power transfer, determine The value of RL. The power absorbed by RL. The efficiency of the circuit, that is, the ratio of power absorbed by the load to power supplied by the source.

  • Answer:

    If you do the calculus on power vs resistance you will find that max power transfer occurs when Rload = Rint. I have done it once and dont want to do it again. When Rload = Rint Rl = 8 ohms Pload = ((Vs/2)^2)/Rload = 4.5W Efficiency of the circuit = 50% (Rload = Rint so Pload = Pint)

thruthew... at Yahoo! Answers Visit the source

Was this solution helpful to you?

Other answers

If you want to go through the calculus: Circuit: Vpos -- Ri -- RL -- Vneg Power to the load: PL = I^2 RL Current: I = V / (Ri + RL) Power to load becomes: RL V^2 / (Ri + RL)^2 = RL V^2 (Ri+RL)^-2 To find the maximum, take the derivative of PL with respect to RL and set that equal to zero (zero slope at the top of a hill) dPL/dRL = V^2 * (Ri+RL)^-2 - 2 * V^2 * (Ri+RL)^-3 = 0 The V^2's can be divided out. And multiplying through by (Ri+RL)^2 leaves the following: (2 RL)/(Ri + RL) = 1 which is true when Ri = RL So maximum power is transferred when RL = Ri and since both resistors also see the same current, their power dissipation will be the same so only 50% of the power gets to the load. (Kinda crummy efficiency actually) But if efficiency is what you are after, then you want a RL that is quite high.

Left_Field

Related Q & A:

Just Added Q & A:

Find solution

For every problem there is a solution! Proved by Solucija.

  • Got an issue and looking for advice?

  • Ask Solucija to search every corner of the Web for help.

  • Get workable solutions and helpful tips in a moment.

Just ask Solucija about an issue you face and immediately get a list of ready solutions, answers and tips from other Internet users. We always provide the most suitable and complete answer to your question at the top, along with a few good alternatives below.