[TCML] Terry filters

[Bill Lemieux]

On Jan 1, 2008, at 7:43 AM, Dave Goodfellow wrote:

> Gary,
>   Thanks for your well thought out reply to my comparison of low  
> pass filters (as used in audio) to transformer protection. Now it is  
> clear to me the basic flaw of using chokes on our NST's.
>
> Best regards, Dave Goodfellow
>
> ----- Original Message ----- From: "Lau, Gary" <Gary.Lau at hp.com>
> To: "'Tesla Coil Mailing List'" <tesla at pupman.com>
> Sent: Monday, December 31, 2007 9:21 PM
> Subject: RE: [TCML] Terry filters
>
>
> Hi Dave,
>
> Your analogy about using just an inductor for a woofer low pass  
> network made me think hard for a moment about my post.  You are  
> exactly right about the requirements for 6/12/18 dB/octave filters.   
> But the woofer situation is very different than NST protection  
> networks and I maintain my position. Allow me to explain.
>
> In the woofer circuit, the load, the speaker, is an 8 Ohm resistor,  
> and forms an integral part of a 1-pole R-L network.  There is some  
> inductance in the woofer, but it's predominantly resistive;  
> otherwise it wouldn't consume power.

What?!?  Hang on a minute.  The woofer is doing _work_!  Your  
statement suggests that a motor wound with superconductor (all  
inductance, no resistance) and delivering 1 HP to a load would consume  
no power!