Lithium
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Registered: 25-2-2012
Location: Australia
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hotplate
hello,
i am looking to buy a magnetic stirrer hotplate, but the only ones i could find ran on 110v, whereas the electricity over here is 240v. to buy a
transformer to fix this problem is at least $100.
does anyone know where i could buy a magnetic stirrer hotplate in Australia, working at 240v, that is not twice to three times as expensive as one
that works on 110v?
Li
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Pyro
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just use a transformer...
all above information is intellectual property of Pyro.  |
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kavu
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Some models might have a wire inside to switch between 240 VAC and 110. Mass produced of electrical appliances sometimes have this functionality
hidden away. It's cheaper to just hook one wire differently in production than to produce a whole new PCB.
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Pyro
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you could just buy one, see if that function is in it, and if not you can use a transformer. they cost about 15 bucks
all above information is intellectual property of Pyro. |
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watson.fawkes
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Quote: Originally posted by Lithium  | | i am looking to buy a magnetic stirrer hotplate, but the only ones i could find ran on 110v, whereas the electricity over here is 240v. to buy a
transformer to fix this problem is at least $100. |
The transformers are expensive because they need to carry
the entire load of the heating element, typically 1.0 kW or 1.5 kW. That's a fair bit of transformer.
The trouble internally is that the resistance of the heating element for 110 V is half of what you need. If that element is made of two sub-elements
wired in parallel, you can rewire them in series to get the right resistance.
If not, there's no easy way to modify it, but there are ways. Assuming that the heating element is a coil of nichrome (or its ilk) wire, you can swap
out just the element. Adequate replacement elements might be found as appliance repair parts, as pottery kiln elements, or from resistance heat
suppliers.
It sounds like your biggest problem is that you don't own one yet. Knowing if its modifiable without having it in your hands is almost certainly not
going to happen.
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adamsium
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I'm in Australia, and while there are certainly hotplates available here, they tend to be comparatively expensive. I've come to the conclusion that
the best thing for me to do is likely to buy a decent used Corning hotplate (probably a PC-420/D) from the US on ebay and just use a step down
transformer, which can be found relatively inexpensively on ebay (~$80 shipped for a 2000 W model; less for a 1000 W model, etc).
A quick ebay search yields products such as this: http://www.ebay.com.au/itm/2000W-STEP-DOWN-TRANSFORMER-STEPD...
I figure such a transformer will be useful for numerous items in the future, anyway. There are many things I'd like that I will probably have to
source from the US, due to either lack of availability here (if buying used equipment), or extortionist pricing. Depending on your plans, you may well
find the same to be true.
I know you said you want to avoid buying a transformer. However, I have done quite a bit of searching and comparing and it seems that if you want a
decent hotplate stirrer, the best option is almost certainly to find a good Corning or similar on ebay, ship it here and use it with a transformer.
The only alternative I am seriously considering is buying one of the high end 'Scilogex' brand hotplates, for around $500 new, locally. My concern
here is that I really don't know anything about that make (beyond the sales literature), whereas Corning has a longstanding and solid industry
reputation as being very reliable and are thus a staple for many. Buying a Corning, plus shipping it here and buying a transformer for it would cost
slightly less (than a new higher end Scilogex) - but not a lot less - than the Scilogex. The nice thing about the Scilogex is that it would be new,
meaning it has a warranty. Its specs also claim some nifty features.
Also, as kavu mentioned, you may well be able to perform a simple modification, if you are so inclined, to enable a 110 VAC device to run on 240 VAC -
no transformer required. You may be able to search for such information prior to making a purchase - you might get lucky and find a how-to guide
somewhere. Otherwise, it would be a lottery; you'd have to purchase the item and, on receipt, open it up and see what can (or can't) be done in terms
of voltage-requirement conversion. Then, if it can be suitably modified and you're able to do so, it's easy. If not, you'll be back to buying a
transformer.
Lastly, I'd also recommend avoiding any temptation to purchase a cheap hotplate / stirrer from China. I actually tried this, against my better
judgement, and have learned my lesson there!
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Lithium
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Registered: 25-2-2012
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thankyou, you have all been very helpful.
i am not very good with electronics and such, so i don't think i will be modifying it.
i think i will do what adamsium said; just found a transformer in melbourne going for $50 and a corning (used) going for $330 (that counts shipping
aswell).
thankyou,
Li
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