Wednesday, December 02, 2009

US Blu-ray player

I got tired of not being able to play US Blu-ray discs here in the UK, so I bought a Panasonic player from the USA.

Now I'm used to be able to gadgets being able to handle both 120 volts and 220 volts with just the flick of a switch or sometimes not even that. But I'm in doubt about this one.
For one thing, the American plug, on the right, is slightly different from the ones I'm used to, it's a bit squared off. The UK lead on the left will easily plug into the machine, but the question is, should I?
Because as you also see, the back of the machine only says 120V, not also 220 like usual.

So doe it require a converter, and is that a simple thing?




John DL said:
Reminds me of an engineer friend of mine... he used to say "all electronics run on smoke... when the smoke leaks out, then it will not work anymore."

15 comments:

  1. It's impossible to tell, with the information supplied at least, whether or not the unit could directly handle a 220V input. Odds are good that it would, but there is no guarantee.

    Mind you, the nameplate indicates a peak power consumption of only 22 Watts, and that's very little.
    I very much doubt that the manufacturer would have anything to gain by using a dedicated 120V-only power supply, but experience dictates that anything is possible when dealing with safety certification agencies...

    If you want to avoid any risk, any travel transformer would handle this situation easily.

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  2. BTW, the North-American plug in the photograph is indeed of a very common type, two-prong polarized (one blade is wider than the other, hence the bizarre look).

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  3. Thanks, dude, you rock.
    (I suspected something like the travel transformer existed, but had no clue how/where to look.)

    What relevance does the low wattage have here?

    ... "polarized"?

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  4. Polarized - http://en.wikipedia.org/wiki/Polarized_plug#Polarisation

    You should definitely get the step down transformer if the back of the unit doesn't say 220v.

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  5. What relevance does the low wattage have here?

    Without entering into details, the size and weight of a transformer is directly proportional to its power rating, and inversely proportional to the operating frequency.

    A simple, 1,500 Watts transformer @ 50/60Hz generally weighs around 50 pounds, and is quite bulky. That's why you buy a travel hair dryer instead of a travel transformer for your hair dryer! :)

    "polarized"?

    The wide blade will allow you to insert the plug in one orientation only. That's a quirk of our power distribution scheme, I guess.


    captcha: wifinese (perhaps I should have written this on my portable :)

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  6. Oh, and I should have mentioned (more to the point, in fact) that the cost of a universal input power supply varies greatly with the power rating. A 22W universal supply is a joke to design, so to speak, and there are really very little cost savings to be realized by optimizing the design for a single voltage.

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  7. Please be careful with high voltages ...

    From the label I interpret clearly, that the device needs an input of 120 Volts AC, and NOTHING else is allowed! So, you need DEFINITELY a step-down transformer converting your 230 VAC into 120 VAC!

    (If you connect directly you may get a nice but short fireworks - there are better ways to spend your money.)

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  8. I've ordered the transformer. (I think it's the one which turns into a racecar.)

    OK, so blu-ray players finally dropped in price. And see here all the shit this fokker can do!

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  9. It has ethernet, USB, and an SD-card slot!

    (I would actually sooner have expected it to have built-in wireless, but it does not seem to have that, weirdly.)

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  10. No WiFi!. You should have bought this one then.

    http://terrywhite.com/techblog/archives/4062

    Regards...

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  11. Ha, a matey of mine was cleaning up his computer, designed for 230 Volts. When done, he switched his compy on again, just by flicking a switch at the back of the enclosure, not seeing what switch it was: alas, it was the 110/230V adjustment switch. The computer gave a flash and a puff of smoke when he set it from the required 230 to the not so convenient 110 V.
    Ah, so you already ordered that inch/cm converter (haha) - good idea. Just to avoid all the additional cable mess I'd recommend you study the power section of the manual. There MIGHT be some hope to be able to switch over to 230V internaly, although the chances decrease when I take into consideration that the name plates states 110V to be used as the sole power source.
    After all, I'm only a cowboy, and just wanted to share that story of the puffing computer with you all. "Oh shit", was all that my mate managed to say, his fingers, face and heart unharmed (which cannot be expected from any accident involving electricity...)

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  12. >>The computer gave a flash and a puff of smoke when he set it from the required 230 to the not so convenient 110 V.

    Reminds me of an engineer friend of mine... he used to say "all electronics run on smoke... when the smoke leaks out, then it will not work anymore." Ha Ha !

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  13. I never really thought about the squared end of the lead, the end that fits into the player. In the UK we had those very polarized 3 pin square plugs, and the end for the boom box was reversible. I mean, you have a transformer, and a bridge rectifier, who cares which way the AC is.

    I guess it makes sense if you have a polarized plug going into the wall, then the other end should be to.

    I had an Acorn A5000 (computer) from the UK, for the longest time we used a 110 -> 220 transformer to power it, it said ~240V on it. Years later I had it open, and I took time to look at the power supply, it was a universal!

    I've heard tell, though I don't believe, that some 60Hz kit isn't happy running at 50Hz long term. If the power supply has some 110V, 60Hz optimization, then, well...

    Come on you're building it in China and shipping to global destinations, the only two differences you want are that one byte of configuration data which sets the default region coding/menu language, and the unique face plate/silk screen.

    As for at work, the first test of new hardware is the "smoke test", that is, does it survive having power applied. I've seen some dramatic failures here. One guy I know let them smoke out of a brand new police car after installing the radio!

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  14. George Georgiev3 Dec 2009, 17:10:00

    You will probably not need any warranty service for this unit anyway, so... The engineer / hacker inside me would take the cover off, and study the inners to see whether or not 240V would be appropriate for it. If you do that, post a picture of power supply (it's probably a small PCB where power cable leads to).

    As for input polarisation, I don't think it matters in any way.

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  15. As for input polarisation, I don't think it matters in any way.

    The polarization has nothing to do with the polarity of the circuit, as in DC circuits, but it has everything to do with safety.

    Your home (assuming you live in North America, other locations have equivalents) is connected to a 240 VAC two-phase mains supply, with two hot circuits and a neutral return. The two hot circuits are 120 VAC each and operate 180 degrees out of phase with one another. One half of the electrical panel is fed with one phase and the other half with the other phase. This provides your home with two 120 VAC single phase circuits and the ability to power 240 VAC appliances.

    Each household circuit uses three wires: hot, neutral, and ground. The ground wire is physically tied to earth somewhere in your home, often to a buried copper rod or to the water supply main. The neutral wire in the circuit connects back to the mains neutral and is tied to ground inside the electrical panel. The hot circuit connects to one of the two 120 VAC circuits. The plugs and outlets are polarized to ensure that the wiring pattern is consistent throughout the home. Some electrical devices do not require polarization and these may come with an unpolarized two-pin plug.

    This is done to protect the user from electrical shocks caused by short and open circuits. If the hot lead touches the neutral or ground, the circuit breaker will trip. If the wiring in your house is done properly, you can touch the ground and neutral wires without receiving a shock.

    Circuit breakers, fuses, and power switches are always placed in the hot circuit. This ensures that the power to an electrical device can be disconnected. For example, if the power switch for a lamp is mistakenly placed in the neutral circuit, you will be able to turn the lamp off and on, but the lamp will always be 'live'. You don't want to put your finger in a live socket and complete the circuit to ground, do you?

    Another example: a damaged appliance cord touching the sheet metal case. This will cause the circuit breaker to trip, if the house and appliance are wired properly. If it is not, or if the plug is not polarized, the case could become live and present a serious shock hazard.

    A three-pin 120 VAC plug has a wide blade, a narrow blade, and a round pin. The wide blade is neutral, the narrow blade is hot, and the pin is ground. In-wall wiring is colour-coded with white for neutral, black for hot, and bare for ground. Power leads usually use a green wire for ground, as all three wires are insulated.

    All homes built in the past 40 years or so have three-wire circuits. You can check the wiring at each electrical outlet using a plug-in circuit tester that costs about $10. You should always check the wiring in any home you plan to buy to ensure the house is wired properly. It is not uncommon to find outlets wired improperly in older homes, with the hot and neutral leads swapped or a disconnected ground.

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