On Fri, 15 Aug 2008 11:33:03 +0100, "N Cook" <diverse8@[EMAIL PROTECTED]
>
wrote:
>Udo Piechottka <UpNews@[EMAIL PROTECTED]
> wrote in message
>news:g83jkc$gok$1@[EMAIL PROTECTED]
>> N Cook schrieb:
>> > Scenario:
>> > a 300 watt toroidal transformer delivering 50-0-50 volts. If there
was a
>> > break in the output paths to load.
>> > So say a current of 2 amps was interrupted, would a high DC voltage
,
>much
>> > higher than mains level, be generated momentarily across the primary
?
>> >
>> >
>>
>> Yes. Due to the leakage inductance of a transformer a suddenly
>> interrupted current could cause a short voltage _spike_ but normally
the
>> spike would be damped by the low impedance of the main voltage net or
be
>> absorbed through the filter network normally found on the primary side.
>>
>>
>>
>> - Udo
>
>
>
>With no filter caps etc in place, straight off the mains, would you care
to
>put a figure on the peak voltage of the spike generated in the primary,
>appearing at the primary , rather than down the supply feed ?
>The secondary interrruption is abrupt due to a faulty broken connection
that
>sometinmes makes sometimes breaks.
>
Not only is the primary still connected to a low impedance source, the
other half of the secondary is still connected to a load. This gives
paths for the field energy to go to. There will be a blip, just not
very large.
|
