Thanks for your reply. You sound like you know what you are talking about, so I am going to take your advice and pack this thing up.... Some other very helpfull folks have suggested the possibility of rewiring the upper and lower elements in series to allow 220V or simply buying a 2nd and wiring in series, but since my skills dont extend to this type of work, I dont have a choice but to pack her away...sniff.....sniff..... I'm overwhelmed by the support of this newsgroup though, people seem very keen to help. Thanks again.
Sorry - the suggestion to wire 2 ovens in series was a bit of mis-placed humour! If the heater thermostat on one oven opens while the other is cooking, all the heater current through the oven that's on will flow through just the motor on the oven with the open thermostat - the cloud of smoke won't be coming from your pizza!
It's not a transformer, it's a converter which is just a big resistor. In order for it to work, it must disapate the electricity that would have gone into the applicance. A worthless piece of junk.
Geoff,
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Plus, a resistor could only be used if the wattage of the appliance was predetermined so the resistance could be calculated! It clearly isn't a resistor.
I'm really pleased to hear that, James. If it's any consolation, you should be able to find a safe and proper alternative, ie a new 240V oven, for not too much cash- there's bargains to be had in this kind of appliance if you look around.
, it won't like it at all. The heating elements might be OK with it, but the raggedy chopped-up waveform will probably confuse its controller.
So I'm going to recommend not even trying it, unless you can verify that the adapter won't blow up your cooker. (or that the cooker won't mind the waveform).
Take my advice- don't take chances with 240V supplies. It is far easier to get a fatal shock from 220/240V than N American 120V supplies, although ELCBs are very common now.. Using one of these cheap converters is dicing with danger, if a short occurs and damages the converter, full 240V mains voltage will be present in your appliance, and because there's seemingly no earth on this converter, if there's a short to the oven's case you could be killed- it's that simple. Even steam/moisture settling inside the oven could bridge from live to chassis causing a shock hazard.
I can tell you by just looking at the picture that this converter is clearly not intended for use with apparatus like ovens, and it doesn't appear to be intended for use with earthed appliances. Either keep this converter for a CD player or shaver, or send it back! I would even go so far as to say it is not safe to plug into a UK wall outlet. It will require a UK 3-pin to 'shaver' style converter for starters, which are not intended to be used for appliances drawing 5 Amps!
Incidentally, there's also the issue of liability should anything happen, is it worth it?
** Then you have no "understanding" of the issue.
** Shame that a resistive load operating from DOUBLE supply voltage requires the power to be reduced by a factor of FOUR !!
Using just a diode will supply the load with DOUBLE its safe power level.
What you are describing is not a real transformer. It is a unit that is employing a circuit that is using a device called a thyristor. This is a solid state gate controlled dual rectifier. They are using a technique of phase chopping to reduce the effective voltage, rather than stepping it down. It can only be used with simple appliances such as hair dryers, lights, and others that are non reactive loads. I would not use it with anything that uses a power supply, or motor device of any kind. Sometimes these units fail, and cause whatever the load is to be damaged.
If you want something safe and reliable, it is best to get a step down unit that uses a real transformer. These are big, heavy, and sort of expensive in comparison.
--
JANA
_____
"James Kelly" wrote in message
news:UaOdnWamQ_rUr7HZRVnyrg@giganews.com...
Hi,
I\'ve recently moved to London in the UK and brought along my trusty cooker.
It states that it requires 120V @60/1235 watts. After some research on the
net it was apparant that transformers that provide > 1000W are at least the
size of a shoebox and around $70-100. However, I later came across a
transformer sold by jWin which rates upto 1600W and is as small as an
average 100w transformer and costs about $10. You can see it here -
http://tinyurl.com/hra3r I called the shop selling them and they confirmed
the specs.... am I wasting my time? You get what you pay for right? Any help
would be much appreciated.
James
The "DIODE CUTS AC POWER DISSIPATION TO SAME AS HALF ORIGINAL VOLTAGE IN RESISTIVE LOAD" thread rears its ugly head yet again!!!!!!
I'm sorry I ever posted in this thread!!!!!!! In my defense I NEVER used the word diode!!!!! Nor did I ever say "Root Mean Square"!!!! I am innocent, I tell you, INNOCENT!!!!
** At 1600 watts, it is rated for more load current than the OPs pizza cooker at 1250 watts.
** Very unlikely to be any problem.
The chopped sine wave produced by the triac (dimmer) has an * rms * value of
120 volts. However, the "average rectified " value is only 64 volts due to the peaky waveform since 2/3 of the sine wave is missing ( conduction angle = 66 degrees out of 180).
The OP's pizza cooker takes a little over 10 amps rms to operate - so similarly, the "average rectified" current level is just over 5 amps.
The triac inside the "converter" has to pass 5.5 amps *average* current with a voltage drop of circa 1.5 volts - so the heat dissipation is only
Just to confirm,( against the general consensus of the group) are you saying that you think it will work and shouldnt pose any serious danger. (I of course assume liability!). I might be willing to give this a go just to see what happens..( wearing rubber gloves of course)!
hmm.. That sounds like a good idea.. you still have the 50/60 hz issue with the timer but as long as that is dc it won't matter. I think you might not even have any probs with it even if it is an ac timer.
Wiring them in series is very easy, but you will need to have 2 cookers and run them both at the same time for everything to work.
Wait.. you'd have problems if this thing has a thermostat and shuts off on one and not the other. It would draw all the current through the timer and the electric moter and instant smoke...
12,350W? That would draw more than 50A at 240V and produce over 42,000 BTU's, that's enough to heat a small house!
1,235W on the other hand is perfectly reasonable for a cooker.
That said, these converters are not transformers, they're essentially triac light dimmers and will only work for purely resistive loads, such as an electric cooker.
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