[Amps] MW Oven Transformer question

[Tony King - W4ZT]

Will,

Do you think that the welded laminations will not be a problem and 
increase losses? Beyond that, what you're saying is good news.

73, Tony W4ZT

Will Matney wrote:
> Gerald,
> 
> My guess by seriesing two will drop the flux density in each to around 10 kilogauss as each will have 1/2 the line voltage across it. That's well below the bottom of the knee and in the linear region. It will raise the power capability X2 also, but I can't say how much without knowing the core dimensions. Two this way though will run as good or better than a lot of off the shelf linear transformers because of the low flux density. This means the efficiency is really high, probably 95% for a rough guess.
> 
> Best,
> 
> Will
> 
> 
> *********** REPLY SEPARATOR  ***********
> 
> On 3/21/06 at 2:22 PM TexasRF at aol.com wrote:
> 
>> Thanks Will and John; I now have an understanding of the heating issues 
>> with 
>> the MOT. It appears that these transformers are really a poor choice for  
>> continuous operation such as a filament power source. Two transformers
>> with the  
>> primary and secondary windings series connected will work and for  testing
>> the 
>> traveling wave tubes is the quick method to be used.
>>
>> Many thanks for your help in my continuing education!
>>
>> 73,
>> Gerald K5GW
>>
>>
>>
>> In a message dated 3/21/2006 11:10:15 A.M. Central Standard Time,  
>> craxd1 at verizon.net writes:
>>
>> If you  want to add turns to the primary (if there's enough room, and
>> should 
>> be with  the secondary removed), you can do a simple test to see how many 
>> turns to add.  First, use the formulas I published last week about
>> figuring the 
>> core size and  number of turns to find the correct number of turns for the
>> core 
>> size you  have. Next, connect the primary to 120 Vac and wind a 10 turn
>> coil 
>> secondary.  Take that secondary voltage and divide it by the 10 turns.
>> That 
>> will be the  turns per volt. Last, wind the extra turns you've found you
>> need by 
>> the  formulas and the known turns per volt. One good thing on this
>> transformer 
>> in  question, the primary is on the inside. If on the outside, you'd be 
>> screwed on  removing the secondary.
>>
>> Best,
>>
>> Will
>>
>> *********** REPLY  SEPARATOR  ***********
>>
>> On 3/21/06 at 11:42 AM John Popelish  wrote:
>>
>>> TexasRF at aol.com wrote:
>>>
>>>> Not what I hoped  to hear but I appreciate the good info! 
>>> If you have a supply  of this kind of landfill, you might put two 
>>> similar units side by  side, wire the primaries in series (effectively 
>>> halving the volts per  turn, so eliminating the saturation problems). 
>>> Then you can knock the  shunts out and wind a similar secondary on each 
>>> (doubling the number  of turns to compensate for the half primary 
>>> voltage) and wire those  two secondaries in parallel.  This gives you a 
>>> reasonably  efficient transformer (that won't overheat without a fan) 
>>> with about a  kVA rating.