
Home  Forums  Rules  Articles  The diyAudio Store  Gallery  Blogs  Register  Donations  FAQ  Calendar  Search  Today's Posts  Mark Forums Read  Search 
Solid State Talk all about solid state amplification. 

Please consider donating to help us continue to serve you.
Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving 

Thread Tools  Search this Thread 
8th December 2013, 05:02 PM  #1 
diyAudio Member
Join Date: Jun 2009

Calculate Resistance from Z and Phase?
My mind must be slipping today. If I have a known impedance with a known phase shift, what is the equation to calculate the parallel capacitance and find the resistance without that phase shift?
Example: 6 Ohms impedance, 30 degrees. I need to find that capacitance value and remove that to then find the resistance at zero shift. Last edited by kouiky; 8th December 2013 at 05:17 PM. 
8th December 2013, 05:19 PM  #2 
diyAudio Member
Join Date: Nov 2003
Location: Brighton UK

Hi,
At 30 degrees the real part is (cos) 0.866xZ R, imaginary is (sin) 0.5xZ. rgds, sreten.
__________________
There is nothing so practical as a really good theory  Ludwig Boltzmann When your only tool is a hammer, every problem looks like a nail  Abraham Maslow 
8th December 2013, 05:42 PM  #3 
diyAudio Member
Join Date: Jun 2009

Does this work for calculating the resistance component of a speaker driver when the Z and phase are known?
Last edited by kouiky; 8th December 2013 at 05:55 PM. 
8th December 2013, 08:01 PM  #4  
diyAudio Member
Join Date: Mar 2003
Location: Haarlem, the Netherlands

Quote:
mag(Y)=1/mag(Z) phi(Y)=phi(Z) G=mag(Y)*cos(phi(Y)) Rparallel=1/G B=mag(Y)*sin(phi(Y)) Cparallel=B/(2*pi*f) Hence, using cos(x)=cos(x) and sin(x)=sin(x): Rparallel=mag(Z)/cos(phi(Z)) Cparallel=sin(phi(Z))/(mag(Z)*2*pi*f) With mag(Z)=6 ohm, phi(Z)=30 degrees: Rparallel~=6.92820323 ohm Cparallel unknown because the frequency is not specified. Examples: f=1 Hz > Cparallel~=13262.91192 uF f=1 kHz > Cparallel~=13.26291192 uF 

Thread Tools  Search this Thread 


Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
2 phase DDS signal generator to run 2 phase AC sync motors  Giordano  Analogue Source  35  16th January 2015 05:25 PM 
6550 plate resistance in triode mode? Calculate?  Koektrommel  Tubes / Valves  4  5th August 2013 12:43 AM 
How to calculate mechanical resistance added by enclosure.  SoulMagnet  Subwoofers  0  10th January 2012 06:25 AM 
Acoustic phase, electric phase,....phase  ermes  MultiWay  6  27th November 2010 06:17 PM 
calculate thermal resistance of alumimium heatsink  bigpanda  Everything Else  1  17th September 2008 09:14 AM 
New To Site?  Need Help? 