# Reducing to Req

Discussion in 'Homework Help' started by Psyleid, Jan 9, 2010.

1. ### Psyleid Thread Starter New Member

Aug 26, 2009
2
0
Teaching myself electronics and I'm stuck on this problem.

I need to calculate the total resistance in this circuit. The problem is I can't figure out what is in parallel and what is in series. To me it looks like R1 is in series with R5 and R4, which are in parallel. After that I can't reduce the circuit anymore.

To me, it appears that if R7 wasn't there, then R3, R4, and R5 would all be in parallel. If R3 wasn't there, then R4 and R5 would be in parallel and R7 would be in series with with the R4, R5 bank.

In the second picture I reduced the apparent R4 R5 bank into it's equivalent resistance. The red circle indicates what resistors I think are in a delta connection (my best guess as to what's going on).

2. ### Psyleid Thread Starter New Member

Aug 26, 2009
2
0
Dang, it just hit me. The R4/R5 bank is actually in series with R7. This new bank (consisting of R4/R5/R7) is actually in parallel across R3.

Funny how stuff just hits you. Maybe I wrong, though.

3. ### hgmjr Moderator

Jan 28, 2005
9,030
215
Your sudden insight is correct.

hgmjr