European appliances in N.A.

I'm surprised as it's normally the other way around - prices cheaper in the USA. Particularly given today's exchange rates. Are you looking for a particular high cost model?

No. I'm looking for a lower-end model. Unfortunately, all the European manufacturers are not making their induction cooktops available in N.A. There are 2 that do: Diva de Provence, which has 2 models available for $3000 and $4000 and AEG has I think 1 available for $3000. The Diva models are manufactured by Die Deitrich (sp?) who also makes the Brandt line, which I can obtain from New Zealand(!) for $1500 or $2000 depending on the model and including shipping and insurance. I'm pretty sure that Diva is making a profit of at least $1000 on each model, if not double that.

In the U.K., one can routinely find Bosch and Siemens induction cooktops for =A3500 to =A3800, which comes in around $1000 to $1500. The only difficulty is determining if it will work.

As I've stated, I don't know enough about how they work to even begin to determine if the cycle difference will be an issue (they all use cooling fans, but my understanding is that the motors would simply run faster).

Colin

Ouch see what you mean.

... perhaps try this site in CA. Has a 4 zone model for $ 1380 - $1600. See "B180X"

Otherwise I'm not sure if 50Hz models will work on 60Hz. I found this site that suggests the "high frequency" type are quite complex beasts.

Here's an idea though. I think some countries like Switzerland and Japan have a mix of 50/60Hz. If their web sites ask which frequency you have then it's a good bet that it matters.

Thanks for the tip about Switzerland. The chart I was looking at didn't list them as having 2 different frequencies.

I'll try giving that company in CA a call. Their site is a little skimpy on info however.

I don't think the high frequency type are really all that complex. It's just a 3kW amplifier driving a coil (and probably incorporating a signal generator). I'm sure the details of the implementation are a bit more complicated (after all, with a 7kW device at 85% efficiency you're going to need to deal with about 1000W of waste heat, so I suspect most of the complexity goes into getting the efficiency up to that level or higher).

I'd still like to know why the mains frequency should make a difference in this type of application. I'm assuming that all the internals will be running DC up until a generated AC current is amplified to drive the induction coils.

Thanks for the info.

Colin

Yes my first thought was that they might rectify the incoming mains to make DC then chop it up to make 22KHz - but then I wondered about the losses in the rectifier. Probably too high for it to be a simple diode bridge. Would they use a synchronous rectifier or some other method not involving DC at all perhaps?

Any idea what the shipping costs would be on something as heavy as a hob? I ask because I'm thinking of importing some bronze window frames from the USA into the UK!

Colin

I have no idea... what's a synchronous rectifier (I have a guess, and I'm going to do some research on the internet to find out)? The manuf.s claim efficiencies of 75% (except for the sole American manuf. that claims 90%), so I think the power supplies must be fairly efficient. I don't know much about AC outside induction motors, so I can't even begin to imagine how one would go about converting a 50Hz signal into a

It turns out the CA site you sent has a website that's 2+ years old and they can't get those models anymore. There are models available that operate on 50/60Hz but I don't know if that's a universal thing, or specific to Brandt's line. I'm a bit reluctant to fork over $1000+ to experiment (nor I am keen to have what I imagine as a "spectacular and catastrophic" failure in my house, involving shooting arcs of electricity and flying bits of shattered ceramic and molten metal, although I do regard that outcome as an extreme longshot).

I think I need to either trick a manuf. into disclosing if it will work on 60Hz supplies, or get in touch with a repair tech who knows how they work. I'm not hopeful I'll have much success with either.

The shipping weight of a hob is 10-15kg and I've been told that shipping and insurance would run about $150-200. Of course shipping from the U.S. end may have different rates. I'm not sure if they would exceed the dimensions for UPS or FedEx, but both sites have shipping rate calculators online. There's also the option of a partial container on a ship, and those costs are in the hundreds for bedroom furniture from Java to Boston. I'm not sure where you'd go to get those rates.

Colin

An ordinary diode use the voltage polarity to switch itself on and off. A synchronous rectifier uses a FET (or anothe active semiconductor device) instead of a diode. However FETs conduct in both directions so some logic is needed to switch the FET on for only part of the mains cycle. That switching has to be synchronised to the mains hence the name. The advantage of using a FET is that the voltage drop during the on phase can be lower than that of a power diode.

Much like a switch mode power supply in a PC.

I assume induction cook tops work like a step down transformer. The primary winding is the cook top coil and the secondary is the bottom of the pan itself. I'm not sure how they compensate for the variability in the type of pan used (or even if they need to).

Good luck

Thanks I'll take a look.

Colin

CWatters schrieb:

Hello,

it seems to be an error in thtat table, look here for Switzerland:

All countries within the European power net use 50 Hz.

Bye

snipped-for-privacy@nospam.com schrieb:

Hello,

the chart was correct. The tip is wrong. Only Japan has 50 and 60 Hz.

Bye