M

#### Mrs. Kerchief

- Jan 1, 1970

- 0

been unable even with the help of a tutor to come up with the Rth

specified by my textbook for the following circuit:

Vs--50V

R1=22 Ohms || R2=22 Ohms, leading at the first node to R3=47 Ohms,

then to the second node R4=33 Ohms. I've just started to learn how to

Thevenize a circuit, and looking back from the open terminals, the

circuit looks like this:

___22___

_____| |______*______________A

+| |__22___| |

50| |

-| 47

| |

|_______33__________|______________B

I apparently got the right Vth by using the voltage divider formula

(47/91) x 50V. But when I tried to get the "right" (according to the

textbook) Rth of 22.7, there was no way I could get that. Looking

back from the open terminals, I put 11 Ohms (the first two resistors

equivalent resistance) in parallel with 47, then that in parallel with

33. I continually came up with an answer of approximately 7.01, not

22.7.

If anyone could tell me what I did wrong, I would appreciate greatly

hearing from you here on this group. Thanks greatly.