Hi poobah,
I am distinctly uncomfortable with this topic. As long as nobody recommends building this - okay. My message is that it's inherently unsafe.
I think you and I agree on that point. Darwin is alive and ready to demonstrate silly ideas to any willing audience.
-Chris
I am distinctly uncomfortable with this topic. As long as nobody recommends building this - okay. My message is that it's inherently unsafe.
I think you and I agree on that point. Darwin is alive and ready to demonstrate silly ideas to any willing audience.
-Chris
I would be concerned if I thought amateurs were building such things. If there are commercial products being built this way, I think amateurs trying to do it is inevitable.
But I agree that we do not really know that much yet.
<<
.... What we need are schematics of such devices that are actually approved and on the North American market. Not intended for professional use. So let's just relax until someone pops up with a full schematic.
>>
But I agree that we do not really know that much yet.
<<
.... What we need are schematics of such devices that are actually approved and on the North American market. Not intended for professional use. So let's just relax until someone pops up with a full schematic.
>>
Not exactly forbidden, just carefully monitored and properly cautioned. What I think Chris is saying (and Chris, correct me if I'm wrong) is that any time someone posts about "off-Line" switchers and other electronics that operate directly off the line they had better know what they are talking about, or that thread will be closed, because of safety reasons.
Noiw, this doesn't mean that ANY products operating directly off the line are no good for N. A., because if that were the case, 10+ million AT & ATX boxes would never have been produced for the Computer market, and we'd still be using real boat anchors.
BTW, Chris, I, too, like the "B" bodies. The early 70's B's with the BB 400's, 455's , etc.... It really is cool watching the stars turn into lines when I take off from a light........... 😀
Steve
Noiw, this doesn't mean that ANY products operating directly off the line are no good for N. A., because if that were the case, 10+ million AT & ATX boxes would never have been produced for the Computer market, and we'd still be using real boat anchors.
BTW, Chris, I, too, like the "B" bodies. The early 70's B's with the BB 400's, 455's , etc.... It really is cool watching the stars turn into lines when I take off from a light........... 😀
Steve
http://www.definitivetech.com/loudspeakers/powertower/powertower.html
I found this company listed in a new magazine. It was their advertisements that I took notice of about 4 years ago. It was their largest tower speakers.
This has a 14" side firing subwoofer. The enclosure size is very small. I have attached a picture similar to what I saw in the magazines.
The cross over for the sub is around 50 or 60hz.
So, they might be operating below the enclosed resonance.
This might be why they want so much power.
Some of these units now go down to 11hz. Some have as much as 1800 watts of sub amp power.
In the adds 4 years ago, they showed the circuit board placement. It looked like there was no transformer isolation. Not 60hz, not high frequency SMPS.
The sub woofer grill cover does not seem to come off.
The design does seem similar to Bob Carver's because of the extreme magnet driver, the high xd, the small box, and the high amp power built in.
Truth is, I don't know if there is transformer isolation. So I am just going to let this sit until someone posts something more definitive.
I found this company listed in a new magazine. It was their advertisements that I took notice of about 4 years ago. It was their largest tower speakers.
This has a 14" side firing subwoofer. The enclosure size is very small. I have attached a picture similar to what I saw in the magazines.
The cross over for the sub is around 50 or 60hz.
So, they might be operating below the enclosed resonance.
This might be why they want so much power.
Some of these units now go down to 11hz. Some have as much as 1800 watts of sub amp power.
In the adds 4 years ago, they showed the circuit board placement. It looked like there was no transformer isolation. Not 60hz, not high frequency SMPS.
The sub woofer grill cover does not seem to come off.
The design does seem similar to Bob Carver's because of the extreme magnet driver, the high xd, the small box, and the high amp power built in.
Truth is, I don't know if there is transformer isolation. So I am just going to let this sit until someone posts something more definitive.
Attachments
I don't. If someone overhere undertakes an attempt to modify such a circuit to run off our mains voltage we soon will have a funeral to attend.
I HATE funerals
Klaas
I am closing this thread. The requirements for safe mains operation are not reflected in schematics and are well beyond the abilities of even skilled amateurs.- Status
- Not open for further replies.