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antrx technical discussion => antrx noise => Topic started by: SAIUN on May 1, 2008, 08:25PM
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Not sure if this counts as off-topic or not, but I figured those in the know would see it in this section.
I bought something from the US, and it came with a US power adaptor with the usual 2 vertical pins. I did a bit of research, and if I understand right since on the back of the power brick it says
I/P: AC 120V 60Hz 8W
O/P: DC 7.5V 500mA
I'd need a step-down converter because we've got 240V power in Australia, right? So would something like this:
http://cgi.ebay.com.au/30W-AC-power-voltage-converter-transformer-240V-120V_W0QQitemZ220219384379QQihZ012QQcategoryZ96942QQtcZphotoQQcmdZViewItem
work for what I need?
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That should be fine for that mate.
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Thanks for the reply. :) I'm not good with electrical stuff so just wanted a second opinion.
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I know enough to get me through but going from what you have said...
I/P: AC 120V 60Hz 8W
O/P: DC 7.5V 500mA
Only need to worry about the I/P (input) which is 120V 8w and the transformer you have looked at is 30w so thats fine, providing the 30w they state is continuous and not peak.
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Only need to worry about the I/P (input) which is 120V 8w and the transformer you have looked at is 30w so thats fine, providing the 30w they state is continuous and not peak.
It may be peak. It says "Loading: 30W or 30VA maximum". If they only state the peak number, then what number should I look for?
EDIT: I can just get one with a higher rating if I need to i.e. 50W or 70W
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Hrmm not 100% sure...
Maybe shoot them a message and let them know the specs of the device your running and let them point you in the right direction.
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It's not really the best way to go about it, you'd be better off trying to find a transformer that goes directly from 240V down to 7.5V, otherwise it's just messy.
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That would be easy providing whatever its plugging into doesnt have a specific plug needed. So without knowing that its a bit harder to say. Take the device down to jaycar and they should be able to help you out.
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simon seriously..walk into jaycar or dicksmith and buy a universal power adaptor. they have a switch on them which lets you select the volatage, usually from 6 to 12v, and 7.5 will be one of them. They cost $30 and come with a multitude of plugs, you just find the one that fits your device and chuck it on the end.
Take yours with you and they'll be able to help you out.
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Alright, thanks for the advice. I'll pop into DSE today.
EDIT: They had exactly what I was looking for. :)
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did they sell any +karma? 8)
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Well, since you asked so nicely... ::)
:P
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Sorry guys, having more trouble with this. Well, a similar thing.
I've got something that runs on 115V and is rated at 24W. I don't know what sort of current it pulls.
I bought a step-down transformer from 240/250V to 110/120V and it works for the most part. It's a guitar amp, and when I turn the volume up beyond a certain point the power cuts out for a moment, then comes back on. I've asked around and have been told it's almost certainly a fault of the step-down transformer I'm using, which is rated at 50W, but I have no idea how much current it's capable of handling (I didn't know it'd be an issue).
So how do I go about finding a transformer that won't cut out? What specs do I need to know about the device I'll be running and the transformer I want to be running it off?
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Is it 110 Volts AC that you require? If it is, it's possibly also 60Hz. A step down transformer isn't going to be able to supply that as in Australia we have 50Hz. Considering though that an amplifier requires DC power ultimately, there will already be some sort of tranformer inside it. Your best bet may be to pull apart the amp, and check what the output voltage is from it's internal power supply, then remove it, and go get a power supply that will go from 240V/50Hz down to whatever it requires, instead of daisy chaining power supplies.
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It's got an internal power supply that rruns on either 50 or 60Hz and 117V (so I think 110V would be fine). I'd rather not be pulling it apart and soldering things together.
Someone else recommended a transformer rated at 1 to 2 Amperes. Would that be fine?
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Without knowing the current draw of the amp its running its hard to know what you need.
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What kranzy said... but, 2 amps at 220 volts is 460 Watts. Or if its 2 amps on the output it would be 220 watts at 110 volts.
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This is all a bit confusing. It's got 24W written on the back where the power cable goes in.
So at 110v it should only draw 0.2A if my maths is right? Or am I missing something? (Never paid attention when learning about electricity in high school Physics :P)
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Yeah sounds pretty close, but I don't know a lot about amplifiers, that might be its rated output peak power or something, I really dont know, but it would be defiantely drawing more than that.
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I reckon your best bet would be to get it converted to 240v.
I don't think frequency would be a problem.