Path: utzoo!mnetor!uunet!husc6!bloom-beacon!gatech!mcnc!ecsvax!hes
From: hes@ecsvax.UUCP (Henry Schaffer)
Newsgroups: sci.electronics
Subject: Re: Running 120V AC equipment off 240V AC.
Message-ID: <4591@ecsvax.UUCP>
Date: 11 Feb 88 01:28:46 GMT
References: <204@unh.UUCP>
Organization: NC State Univ.
Lines: 29
Keywords: step-down transformer, resistive/inductive loads
Summary: voltage converters aren't always transformer  (the
	 non-transformer ones can't be used with everything)

In article <204@unh.UUCP>, abc@unh.UUCP (Avinash B Chopde) writes:
> 
> A question about stepping down voltage.
> 
> I went into a Radio Shack shop to get a transformer (primary 240V,
                                          ^^^^^^^^^^^
> secondary 120V) so that 120V equipment can be run off 240V AC supply.
> 
> I thought only the wattage should be important in such a transformer,
                                                           ^^^^^^^^^^^
> but the salesman told me that the 1000W unit they have will work only for
> hair-dryers, and cannot be used for motors (food processors, etc) even if
> they are of lesser wattage.
   The problem is that everyone concerned seems to be assuming that a
240->120 volt converter has to be a transformer.  A transformer does work
fine and can run anything, but tends to be big and expensive in the high
current/wattage sizes.  
  For much less money and in a much smaller package you can put a
half-wave rectifier rectifier which will give you the same effect - *for
loads which don't care about the wave-form*.  Note that this generally
includes resistive loads (such as heaters - which is where the high
wattage is important) - but doesn't generally include audio equipment.
Some motors will work, others won't (vagueness intentional :-).
> ...
> =================================
> Avinash Chopde  (abc@unhcs.CSNET)
> =================================

--henry schaffer  n c state univ