Amps
[Top] [All Lists]

Re: [Amps] Need Japan Radio Plate Transformer Info

To: <w2cqm@juno.com>, <amps@contesting.com>
Subject: Re: [Amps] Need Japan Radio Plate Transformer Info
From: "Tom W8JI" <w8ji@w8ji.com>
Date: Fri, 1 Sep 2006 04:51:32 -0400
List-post: <mailto:amps@contesting.com>
> for a retrofit!  The plate transformer is stenciled for 
> 200VAC input
> with an output voltage of 2400VAC. I put 240VAC on the 
> inputs and the
> voltage increased to about 2800VAC (no load) with no 
> indication
> (vibration, noise, heat, etc)  that there was a problem 
> with the over-
> voltage. Based on that observation, my feeling is that 
> it's wound for
> 240VAC and the manufacturer simply used it on 200VAC since 
> that's the
> normal voltage (100/200vac)  in Japan.  Does anyone have 
> any
> experience using Japan Radio transformers on higher input 
> voltages?

Ron,

Other than insulation requirements which can generally be 
ignored (since there should be a lot of headroom) here is 
what happens.

You have a transformer designed for 200 V 50 Hz. This means 
flux density with no load was set at a certain safe level 
for that voltage and frequency.

You increased frequency 60/50 = 1.2 times. This lowers flux 
density to 83.3% the original design levels by this change 
in operating frequency.
You increased voltage by 240/200 = 1.2 times. This increases 
flux density by 16.7% back to 100% by this change in 
operating voltage.

You now have very close if not exactly the same flux 
density. The transformer, other than having more voltage, 
sees no difference at all.

73 Tom 


_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps

<Prev in Thread] Current Thread [Next in Thread>