[Hallicrafters] Re: [Boatanchors]Replacing recttubeswithdiodesquestion

[jeremy-ca]

Interesting devices, thanks, Ive just been reading some data sheets.

I was thinking of an entirely different active circuit that would be used at 
substantially higher energy levels.

Carl
KM1H


----- Original Message ----- 
From: "J Forster" <jfor at quik.com>
To: "jeremy-ca" <km1h at jeremy.mv.com>
Cc: "Rodger" <wq9e at dtnspeed.net>; <Boatanchors at mailman.qth.net>
Sent: Wednesday, February 13, 2008 7:03 PM
Subject: Re: [Hallicrafters] Re: [Boatanchors]Replacing 
recttubeswithdiodesquestion


> jeremy-ca wrote:
>
>> [snip]
>> > The NTC inrush limiters I use have a fairly high cold resistance which
>> > drops quickly as they warm up due to current draw.  The ramp up in 
>> > voltage
>> > can be easily measured.
>>
>> As I stated, they operate at the zero crossing and provide minimal
>> protection. [snip]
>
> NTC (Negative Temperature Coefficient) devices are LINEAR (as long as the
> applied waveform is shorter than the thermal time constant of the device.)
>
> http://en.wikipedia.org/wiki/Thermistor
>
> They act as a series resistor and have nothing to do with zero crossings.
>
> -John
>
>
>