snowden@sequoia.cray.com (Jim Snowden) (06/04/91)
I'm going to try running a CD-ROM player (US 110V) in the UK and someone told me I could use a transformer to convert the voltage, but not to use a triac. Could someone tell me what a triac is and why it wouldn't be suitable? (I think I have one of these triac convertors from Radio Shack but I don't want to use it if it would break the CD-ROM player!). Thanks for any help, Jim Snowden, snowden@sequoia.cray.com
stevem@specialix.co.uk (Steven Murray) (06/04/91)
snowden@sequoia.cray.com (Jim Snowden) writes: >I'm going to try running a CD-ROM player (US 110V) in the UK and someone told >me I could use a transformer to convert the voltage, but not to use a triac. >Could someone tell me what a triac is and why it wouldn't be suitable? >(I think I have one of these triac convertors from Radio Shack but I >don't want to use it if it would break the CD-ROM player!). >Thanks for any help, >Jim Snowden, snowden@sequoia.cray.com There are two ways to convert 240v to 115v - with a transformer, and with a sort of a 'switcher' unit that just lets part of the sine wave through - it chops up the waveform - so that something like a lightbulb gets as much power as if it is running off 115 vac when really it is running off hacked up 240 vac. That the point - this works fine with things like light bulbs, but anything electronic will be rectifying the voltage, and thus will see the full 240v still .... BANG! :-) Don't use 'triacs' as he says! Regards Steven Murray -- Steven Murray uunet!slxsys!stevem stevem@specialix.co.uk I must write out one thousand times "I will not leave myself logged in" main{int a;for (a=0;a<1000;a++)printf("I must not leave myself logged in");}
rando@skipper.dfrf.nasa.gov (Randy Brumbaugh) (06/04/91)
In article <035305.13208@timbuk.cray.com> snowden@sequoia.cray.com (Jim Snowden) writes: >I'm going to try running a CD-ROM player (US 110V) in the UK and someone told >me I could use a transformer to convert the voltage, but not to use a triac. > >Could someone tell me what a triac is and why it wouldn't be suitable? Well, . . . A triac is a solid state device which looks something like a transistor, and works like 2 silicon controlled rectifiers, wired in opposite directions for swithing AC, etc. But, . . . The triac has no application I know of in voltage conversion. Maybe in switching power supplies or something. However, there is a voltage conversion device called a Variac. This is a variable transformer -- I think Variac is a brand name. It looks like a round (usually grey) can with a control knob on top -- to adjust the voltage. These are used for things like dimming lights. Usually the output can be adjusted from something like 20% - 120% of the input voltage. They come in various sizes, depending on the application. I think this may be the device you were warned against using. Yet, . . . I can't think of any reason this wouldn't work for voltage conversion for a CD player. (Disclaimer: just because I can't think of a reason doesn't mean there isn't one). Can anybody else think of a reason a Variac should not be used for converting voltages? Randy Brumbaugh rando@skipper.dfrf.nasa.gov
barrie@extro.ucc.su.OZ.AU (Barrie Egerton) (06/10/91)
Don't use a triac device (see previous postings).
A Variac is a single coil variable "transformer" and NOT isolated from the
main s supply - I suggest that you don't use one of those either.
WAIT until you get to England and go to any of the hobbiest electronic shops
in Edgware Road (take the Underground {subway} to "Edgware Road" station and
walk north (away from Marble Arch) or get a taxi to "Paddington Green Police
Station" - just around the corner). Henry's Radio should be able to supply a
step-down transformer but there are lots of other shops worth a visit. You
can buy anything electronic in that area. Nearest cross-street is Church
Street.
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Barrie Egerton, School of Medical Radiation Technology, University of Sydney,
P.O. Box 170, Lidcombe, N.S.W. 2141, Australia. Tel/FAX: +61-2-646-6514/4853.
--------------------------------------------------------------------------------snowden@sequoia.cray.com (Jim Snowden) (06/10/91)
Thanks for all the good advice on triacs and using 110V equipment in the UK (240V). In the end, I just bought a 110/240V autotransformer and the CD-ROM unit works fine. --Jim Snowden