Cap or caps on ac inlet ?

[pinkmouse]

Originally posted by runebivrin
Are you suggesting that every component in a comupter power supply - which switches the rectified mains voltage - are somehow "mains rated"? Every single resistor?

If it has mains voltage across it, then yes, or it wouldn't get it's CE ,(or UL in the States), rating.

As for your Christmas lights, if you went out to a reputable dealer today, I bet you wouldn't find anything but low volt versions...

[runebivrin]

Originally posted by pinkmouse

If it has mains voltage across it, then yes, or it wouldn't get it's CE ,(or UL in the States), rating.

Well, that's really the point, isn't it. The cap in the DC filter we're discussing doesn't have mains voltage across it. The LC Audio version will suffer at most 4.3 volts. My schematic only goes to 0.7 volts, so a 25 volt cap will be quite safe.

Originally posted by pinkmouse

As for your Christmas lights, if you went out to a reputable dealer today, I bet you wouldn't find anything but low volt versions...

Not so, not in Sweden at least. Almost every houshold has at least one electric candle holder with 7*34 volt 3 watt incandescent lights that plug directly into the wall socket. Thousands are sold every year. Christmas trees will have light chains with 18 14 volt bulbs (or was it the other way around - hm, christmas stuff neatly packed now). Sure, you can get stuff with LEDs, but that isn't nearly as cosy.

Rune

[pinkmouse]

I see no CE mark on that circuit pcb...

[inteificio]

Jumping back to christmas lights there.

It is a common (and too frequently fatal) mistake to assume christmas lights are low voltage.

One of the bulbs was shattered in my setup this christmas. without unplugging it i ripped out the bulb (with now exposed metal contacts) and plugged in the new one.

A few seconds later two neurones connected and i realised my lights did not have a transformer!



Then again i have rewired a broken electrical lamp before.
Halfway through i felt a funny tingle in my hand. suddendly my megahungover brain realised the light was in the mains and turned on.

The "tingle" was electrisity passing through my hands!

Long story short electricity kills...though not when you are hungover.

[runebivrin]

Originally posted by pinkmouse
I see no CE mark on that circuit pcb...

Agreed - you don't. I'm not quite certain, but I think the laws concerning electrical safety in Europe are different that what one might suppose - and what used to be. From what I gather you're pretty much allowed to manufacture and sell anything. If it causes injury or material damage and it's not CE certified you're in deep trouble. CE certification is something anyone can slap onto their product, but if in fact the product doesn't meet certification standards you're in even bigger trouble. If it is CE certified, meets the standards but somehow causes injury or damage anyway that's too bad, but accidents will happen.

In short: You as a manufacturer vouch for its adherence to CE standards, but it's wise to have it tested by a certified lab. It's up to consumers to look for the CE mark.

Back in the good, old days, before Sweden joined the EU, it was mandatory to have any mains powered electrical device tested and certified by SEMKO (the Swedish Electrical Material Checkup Organization). It could the be stamped with a ringed S, which was compulsory for devices sold to consumers. SEMKO still does a lot of the CE certification tests. Expensive but rigorous, and the S mark is still well recognized as a sign of electrical safety in Sweden.

Rune

[runebivrin]

Originally posted by Peter Scowcroft
Jumping back to christmas lights there.

It is a common (and too frequently fatal) mistake to assume christmas lights are low voltage.

One of the bulbs was shattered in my setup this christmas. without unplugging it i ripped out the bulb (with now exposed metal contacts) and plugged in the new one.

A few seconds later two neurones connected and i realised my lights did not have a transformer!



Then again i have rewired a broken electrical lamp before.
Halfway through i felt a funny tingle in my hand. suddendly my megahungover brain realised the light was in the mains and turned on.

The "tingle" was electrisity passing through my hands!

Long story short electricity kills...though not when you are hungover.

Back in my younger days I worked a few years servicing consumer electronics. We had a contract to do service on the school gear in our town, which meant that every summer we tended to countless Tandberg reel-to-reel tape recorders. My "favourite" foul-up was to plug the thing in, test it superficially and then unscrew the chassis to look at the innards. At which point I routinely took a firm grip with my right hand across the mains switch. ZAP! We had full isolation transformers, and nothing really bad ever happened, but every time I swore it was the last time. I still get zapped once or twice a year, but I keep one hande in the pocket, so it just gives me the jitters.

Live and learn? Or maybe learn and live!

Rune

[pinkmouse]

Yes, that's very much how I understand the rules as well.

As for the christmas lights, a couple of years ago I had to get 1000 sets for an event. Mains voltage would have been perfect as we could have just spliced them into big ring mains. However, even dealing with the importers direct, I could only get LV in the UK, which was a real pain as it involved about twice as much work running sockets everywhere...

[TANDBERGEREN]

Originally Posted by ROVSING

no more like this...

Those caps should be of quite mech size to allow power in excess of a few watts to pass through them. Have in mind the effects they will have to match the inductive forrces within the apparatous. Value needed is a couple of thousand microfarads at least.

I see another here seems to believe they are some DC-blocking effect that is wanted here, and to protect the caps with a diode across them? POF, there goes the DC-protection.

I have never seen any household equipment with caps connected as this.