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Re: Measuring k




From: 	Malcolm Watts[SMTP:MALCOLM-at-directorate.wnp.ac.nz]
Sent: 	Wednesday, September 17, 1997 3:22 PM
To: 	tesla-at-pupman-dot-com
Subject: 	Re: Measuring k

Hi Julian,

> From:   Julian Green[SMTP:julian-at-kbss.bt.co.uk]
> Sent:   Wednesday, September 17, 1997 7:54 AM
> To:     tesla-at-pupman-dot-com
> Subject:    Re: Measuring k
> 
> > 
> > k = 1/(2 x T x Fr)  where T = time taken to ringup (half a complete 
> > beat hump). The formula is an approximation for the lossy case.
> > 
> > Also approximate:  k = (Fhi-Flo)/Fr   where Fhi and Flo are the two 
> > sideband responses you can see when running the primary from a signal 
> > generator and monitoring the two response frequencies on a scope.
> > 
> > Malcolm
> 
> k = 1/(2 x T x Fr) 
> 
> T is time of full beat hump
> Fr is Frequency in Hz
> 
> The 2x is needed to split the full beat hump in half to the point of 
> full ring up voltage, and T x Fr gives the number of cycles.

Disagree. 
 
> By observing the wave form on a scope the number of cycles needed to 
> reach full ring up voltage can be counted so:
> 
>               1
> --------------------------- = k
> NumberOfCyclesForFullRingup

On my large system, k is set at 0.12 or near as. Cycles to ringup = 
3.5 - 4, Fr = 150kHz.

> But what is this? k = (Fhi-Flo)/Fr

See above. If you sweep the sig gen, the coupled system gives two 
responses with a null at Fr. If Fr doesn't produce a null, either 
something is being done wrong or the system is undercoupled re spark 
production.

Malcolm