Author Topic: 110v to 220v transformer.... I have an honest question.  (Read 605 times)

Offline Hi-Phibian

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Re: 110v to 220v transformer.... I have an honest question.
« Reply #15 on: February 14, 2018, 03:02:54 PM »
We have equipment, like Oppo for eg, that can be bought in the USA and be brought here and you select the voltage on the back for RSA use to 230V. That switch option must mean an internal onboard stepdown/stepup transformer built in. They would surely not provide that if it affected sound quality?


Nope.  It just means the transformer has a dual primary and the winding are put in parallel for 110 and series for 220. 
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Re: 110v to 220v transformer.... I have an honest question.
« Reply #16 on: February 14, 2018, 03:52:31 PM »
It simply means that the transformer is designed for 50Hz AC mains and has two tappings, 0 - 110V(/120v) AC each. These are placed in series for a 220-240v country, or in parallel by means of the voltage selector switch for the USA and toher 110v countries. Other tappings are also generally available, but the actual transformer is a one-piece affair.

USA transformers are designed for 60Hz 110v nominal supplies and could get warm when run in a 50Hz environment.


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Re: 110v to 220v transformer.... I have an honest question.
« Reply #17 on: February 14, 2018, 04:59:14 PM »
Thanks.

Have learnt something here !!  :2thumbs:

Online bbe22

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Re: 110v to 220v transformer.... I have an honest question.
« Reply #18 on: February 14, 2018, 09:18:58 PM »
USA transformers are designed for 60Hz 110v nominal supplies and could get warm when run in a 50Hz environment
I wondered too, (from first hand experience) why ? and google provided........

Yes, a 50 Hz transformer can run on 60 Hz with no ill effects. The transformer design does not impose any practical upper limit on how much the supply frequency can exceed the rated frequency, but a supply frequency lower than the rated frequency has the same effect as an overvoltage.

Therefore running a transformer at a frequency lower than its design rating can cause damage to the transformer. 60Hz transformers are smaller and less expensive than 50/60HZ transformers. We do not recommend specifying a lower rated frequency than needed since a 60Hz transformer has 20% higher rated power than a 50Hz transformer of the same size and weight. The design construction of a 50Hz transformer is usually larger than that of the 60Hz.

and

A 60 Hz transformer will work at 50 Hz provided the excitation voltage is lowered by the same proportion otherwise the iron core can be overexcited and driven into saturation producing excess heat and pronounced waveform distortion of the secondary voltage and primary current.   So if the frequency is reduced from 60 to 50 Hz (0.833 per-unit), and the excitation voltage remains constant, then the magnetic flux in the core will increase by 20 %


So , my take on it ..........as long as the unit  is over specced to cover the potential shortfall at 50Hz  its ok .........and can be used  connecting it as FD suggested if the primary tappings allows