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I have question about R L Mathematics
On 1/28/2014 2:12 PM, John S wrote:
Hi, Mike - On 1/28/2014 1:14 PM, amdx wrote: On 1/28/2014 1:03 PM, amdx wrote: I have beads* on a coax and want to know the R and the L. I have measured the R at 3.85MHz, It is 3,350 ohms. I will assume that Z is 3350 ohms at 3.85MHz. I have also measured the phase shift, voltage leading by 17ns. The period of 3.85Mhz is 260ns. I want to calculate the impedance of the reactance. The impedance of the reactance (alone) IS the reactance (itself). Can anyone solve this for me? I will try. I would like to see the math, because I want to measure again at 7.5MHz. My first step was to find the phase angle, 23.5*. Do we agree there? We do (based on your numbers)... Z = 3350 @ 23.5 degrees. R = Z * COS(23.5) and X = Z * SIN(23.5) Therefore, R = 3072 ohms and X = 1336 ohms As a sanity check, Z = sqrt(R^2 + X^2) = 3350 Good! HTH, John S Thank you John. Mikek |
#2
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I have question about R L Mathematics
On 1/28/2014 3:18 PM, amdx wrote:
On 1/28/2014 2:12 PM, John S wrote: Hi, Mike - On 1/28/2014 1:14 PM, amdx wrote: On 1/28/2014 1:03 PM, amdx wrote: I have beads* on a coax and want to know the R and the L. I have measured the R at 3.85MHz, It is 3,350 ohms. I will assume that Z is 3350 ohms at 3.85MHz. I have also measured the phase shift, voltage leading by 17ns. The period of 3.85Mhz is 260ns. I want to calculate the impedance of the reactance. The impedance of the reactance (alone) IS the reactance (itself). Can anyone solve this for me? I will try. I would like to see the math, because I want to measure again at 7.5MHz. My first step was to find the phase angle, 23.5*. Do we agree there? We do (based on your numbers)... Z = 3350 @ 23.5 degrees. R = Z * COS(23.5) and X = Z * SIN(23.5) Therefore, R = 3072 ohms and X = 1336 ohms As a sanity check, Z = sqrt(R^2 + X^2) = 3350 Good! HTH, John S Thank you John. Mikek It makes me feel good that I could assist. So, I thank you as well. Cheers, John S |
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