A rheostat in the primary of the filament/heater transformer is a
convenient way to adjust filament/heater V.
>While the ferro-resonant transformer seems like a good idea
>at first--there are some issues. The main thing is that they
>work at a single line frequency. So you can't use only one
>transformer for 50 and 60 Hz. And they show reverse
>regulation with variable frequency line voltage from generators.
>Plus they are relatively bulky and expensive.
>
>A more viable solution -- is active regulation with a Triac
>and an RMS detector.
>
>But this means that the vast majority of hams would have to
>pay for something they don't need just to aid the few that
>have out of spec AC line regulation.
>
>Life is a balance between what is realizable and what is
>affordable. Get used to it. ;-)
>
>John W0UN
>
>
>
>>Thinking about the issue of keeping the filaments cooking at +/- 5%
>>of nominal rating for longest life...
>>
>>Seems to me that a saturable core type transformer would fit that bill
>>perfectly... certainly would regulate the voltage. You know, similar
>>to those 120v AC supplies that do the same trick.
>>
>>In fact, I think I have some that are 6.3v saturable core trannys from
>>something or other... obviously you'd need some that were wound *for*
>>the desired voltage.
>>
>>Anyone got any thoughts on this?
>>
>> _-_-bear
>>
>>--
>> _-_-bearlabs
>>
>> http://www.bearlabsUSA.com
>> - Silver Lightning Interconnects & Custom Mods -
>>
>>
>>_______________________________________________
>>Amps mailing list
>>Amps@contesting.com
>>http://lists.contesting.com/mailman/listinfo/amps
>
>
>_______________________________________________
>Amps mailing list
>Amps@contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
>
- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
www.vcnet.com/measures.
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