Author Topic: Beefy, linear power supplies  (Read 13074 times)

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Offline gregariz

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Re: Beefy, linear power supplies
« Reply #25 on: March 24, 2012, 07:49:42 am »
Your real problem is that Amplifiers are a consumer item.

If you stick to plug packs (wall warts) you are free of electrical licensing as you know, so I think you are on the right track there. I bought a rather large 55 watt 18VAC 2.2Amp plug pack recently for a radio application that cost me less than $20 at Jameco. However it is a US only voltage. So I suspect they must be out there.

Maybe something like

http://www.jaycar.com.au/productView.asp?ID=MP3045&form=CAT2&SUBCATID=1000#12

If you stick to designing test equipment, R&D equipment, unfinished products, boards and kits you are generally also exempt of EMC/FCC requirements. ie all of the kits, boards and modules you see people selling all over the net without any regulatory hurdles. If it were me, and I wanted to do a consumer item, as I said above I would probably do it in Asia.

I'm digging into some long lost memory here but I thought that one way around plugging into the mains was to use an isolation transformer. Something like the following

http://www.flanagan.com.au/isolation.htm

Technically then you are not plugging into the mains. I wouldn't run the idea past the electrical board because their standard answer is no but my guess is that you wouldn't find anyone who could tell you that was legal or not - but at least if they did find out and crack a fat about it you could demonstrate that you had a good dig to do the right thing. Again, its easier to ask for forgiveness.

« Last Edit: March 24, 2012, 08:07:04 am by gregariz »
 

Offline mikeselectricstuff

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Re: Beefy, linear power supplies
« Reply #26 on: March 24, 2012, 11:57:23 am »
Quote
You could offer it for sale as a kit, however the rules have changed in europe so that many kits now also require EMC certification through a test lab as well. Kits are still exempt from EMC in the US and Aus (AFAIK at last look).
No normal (i.e. not medical or other specialist areas) in Europe requires EMC certification by a test lab - manufacturers can self-certify that a product meets the requirements
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Offline nukie

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Re: Beefy, linear power supplies
« Reply #27 on: March 24, 2012, 02:29:51 pm »
David Aurora - if you become a politician one day I will definitely root on ya.
 

Offline harnon

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Re: Beefy, linear power supplies
« Reply #28 on: March 24, 2012, 02:43:18 pm »
Quote
You could offer it for sale as a kit, however the rules have changed in europe so that many kits now also require EMC certification through a test lab as well. Kits are still exempt from EMC in the US and Aus (AFAIK at last look).
No normal (i.e. not medical or other specialist areas) in Europe requires EMC certification by a test lab - manufacturers can self-certify that a product meets the requirements
From my reading of the CE certification directives its one of those lovely legal situations where you aren't required to go to a lab but if you self-certify and then get audited, if you can't provide documentation to say you are compliant (e.g. lab test results) you'll get shafted.
 

Offline mikeselectricstuff

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Re: Beefy, linear power supplies
« Reply #29 on: March 24, 2012, 03:51:30 pm »
Quote
You could offer it for sale as a kit, however the rules have changed in europe so that many kits now also require EMC certification through a test lab as well. Kits are still exempt from EMC in the US and Aus (AFAIK at last look).
No normal (i.e. not medical or other specialist areas) in Europe requires EMC certification by a test lab - manufacturers can self-certify that a product meets the requirements
From my reading of the CE certification directives its one of those lovely legal situations where you aren't required to go to a lab but if you self-certify and then get audited, if you can't provide documentation to say you are compliant (e.g. lab test results) you'll get shafted.
In theory, but in practice the system is complaint driven, so you won't get ranomly checked (except possibly in Germany), and even then ISTR you have something like a couple of weeks to come up with documentation.
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Offline gregariz

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Re: Beefy, linear power supplies
« Reply #30 on: March 24, 2012, 07:16:23 pm »
In theory, but in practice the system is complaint driven, so you won't get ranomly checked (except possibly in Germany), and even then ISTR you have something like a couple of weeks to come up with documentation.

Yes you are right, if I were a small business in europe the only way forward would be to try my best to produce some kind of self certification document. In the US the only people we really see getting actively pursued by the FCC are people selling intentional radiators (ie wireless devices). There's usually a regular list of ebay sellers on the FCC's database who have been fined or warned. As a general rule I doubt they care about much else unless they get a complaint.
 

Offline gregariz

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Re: Beefy, linear power supplies
« Reply #31 on: March 26, 2012, 07:59:54 pm »
I was just looking through my doc folder and I found this. Maybe it gives another perspective from that of a test lab. They would probably give you better advice than the electrical authorities

Edit: I thought about this for some reason and something seems funny in the whole thing to me. Most of the arguments about this topic that have occured over the years have to do with whether electrical engineers should be able to do fixed wiring, ie change a socket in their house. (The result has always been no) I've never heard of the electrical authority shutting down an electronics manufacturing enterprise because they used a power transformer in a piece of consumer electronics. The reason that I would typically use a plug pack is not because of the electrical regulations not allowing me to wire it but because it relieves me of having to get product certification testing at a test lab which is very expensive. Australian manufacturers do use minimally trained people to do electrical wiring and assembly as long as they work to an instruction prepared by an engineer/competant persons. Queensland has always been a bit funny but they've gone to the extreme of restricting the changing of plugs and cords (IIRC) which all the other states allow the public to do.

see the following exemptions for nsw (QLD is the same apart from the plugs and cords (Ithink?));

http://www.legislation.nsw.gov.au/fragview/inforce/subordleg+674+2011+ch.4-pt.4.7-div.1-sec.146+0+N?tocnav=y
« Last Edit: March 26, 2012, 10:22:21 pm by gregariz »
 

Offline e100

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Re: Beefy, linear power supplies
« Reply #32 on: April 09, 2012, 01:54:33 am »
Re-sell bench power supplies instead of plug packs, remove the voltage/current control knobs to stop people changing the settings and connect the suitably insulated low voltage outputs to your custom electronics.
Market the thing as a two distinct products that are sold as a pair, one part 'certified mains safe', the other extra low voltage electronics.
 

Offline mobbarley

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Re: Beefy, linear power supplies
« Reply #33 on: April 09, 2012, 12:28:50 pm »
how about series / parallel strings of plug packs.....  ;D
 


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