[ARC5] Bucking transformer configurations.

[Brian Clarke]

Well hello Robert,

How nice to have your 0.02c worth.

Any electrically-oriented person can read the Subject field. It says 
'Bucking transformer configurations'. It says nothing about old radios. And 
if you hadn't noticed anything in this stream about older transformers, then 
you just haven't been paying attention, boy.

And who are you to pontificate about what is the 'normal way'?

Please just focus on the generic content and let Forster do the personal 
urinating on people from his lofty 5000-degree perspective.

----- Original Message ----- 
From: <WA5CAB at cs.com>
To: <arc5 at mailman.qth.net>
Sent: Tuesday, December 11, 2012 2:48 PM
Subject: Re: [ARC5] Bucking transformer configurations.


> In the first place, I don't recall anyone talking about using vintage
> buck/boost transformers.  I agree with John.  There is no valid excuse not 
> to
> connect the equipment in the normal way.
>
> Also, no one wrote anything (or nothing useful) about any appliances.  The
> subject was vintage radios designed for either 110/60 or 220/50 mains.  If
> you want to complain about the low quality of your washer or cooktop, go 
> find
> the appliance list.
>
> In a message dated 12/10/2012 20:25:32 PM Central Standard Time,
> jfor at quikus.com writes:
>> I know perfectly well that you were proposing to raise the low side of
>> the
>> equipment 'only' 10 VAC or so above neutral.
>>
>> My opinion remains unchanged. It's just plain nuts. The possibility of a
>> transformer insulation failing at 115 VAC is improbable in the extreme. 
>> It
>> your transformer is that marginal, it is junk.
>>
>> YMOV,
>>
>> -John
>>
>> ===================
>>
>>
>> >What I suggested was that the downstream appliance would have its 
>> >neutral
>> >off ground, not the incoming mains. The incoming mains neutral and 
>> >ground
>> >would be at essentially the same potential except for IR-induced drops 
>> >in
>> >the neutral side of the permanent wiring.
>> >
>> >Perhaps the English we speak south of the equator is different from that
>> >north. Neil understood exactly what I meant.
>> >
>> >If you do the maths, you will see that the chassis will be no more than
>> 10
>> >Vac adrift from ground. This is insufficient to stress even cheap
>> >accountant-designed transformer insulation. But if you have been cooking
>> >old 110 V transformers at 130 V, the insulation is likely to be less 
>> >than
>> >wonderful.
>> >
>> >Another possibility that might explain John's unreferenced opinion, is
>> >that much American stuff that has survived the rigours of shipping south
>> >has one of its two-wire mains input leads connected to the chassis. This
>> >is a habit that leads to electrification of the operator when using
>> >non-phased two-pin mains plugs. Most modern appliances (designed in
>> >Australia, Europe and New Zealand) ensure there is at least 3 kV
>> isolation
>> >between both incoming mains leads and the chassis of the appliance. But
>> if
>> >you let accountants design your stuff, really, what can you expect.
>> >
>> >73 de Brian, VK2GCE.
>> >
>> >
>> >
>> >>Kenneth G. Gordon <kgordon2006 at frontier.com> wrote:
>> >>
>> >>On 10 Dec 2012 at 14:50, J. Forster wrote:
>> >>
>> >>>I understand, but repeat: IMO, bring the neutral off ground is
>> >>>always a bad idea.
>> >>>
>> >>>If any 115 V transformer is going to break down at 115 V anywhere it
>> >>>is junk.
>> >>
>> >>I will repeat, since I didn't send my earlier reply to this to the 
>> >>list:
>> >>
>> >>I agree absolutely with John concerning the neutral: if it isn't tied
>> >>directly to
>> >>ground, I ain't doing it.
>> >>
>> >>Secondly, I have never, ever had any transformer I have ever used as a
>> >>bucking transformer fail.
>> >>
>> >>And I always use the "non-autotransformer" connection.
>> >>
>> >>Ken W7EKB
>> >>__________________________________________________________
>
> Robert & Susan Downs - Houston
> wa5cab dot com (Web Store)
> MVPA 9480
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