New UL rules

We buy wall warts that have all the UL/CSA/VDE stickers, and run 5 to

Yup, us too, except that we've standardized on 24V because that way the boxes are harder to blow up. ;)

I'm mainly thinking about that APD power supply. It has three separate current limit circuits, so it can't go above 5 mA unless they're all broken, but it goes up to 250V.

Cheers

Phil Hobbs

Right. If you design for 5 or 12, somebody will plug in the wrong wart. Few people have 48 volt warts lying around.

Do you plan to get it UL listed? That's a gigantic hassle.

LLNL considers 9 joules to be the threshold of lethality. Your thing sounds harmless.

My new 1200 volt pulse generator is slick. You can touch anything on the board and you can't feel a tingle. Short pulses.

So a 1V, 3mAh battery will need certification?

We need a symbol, a tongue with a slash through it, and the warning DO NOT LICK in 19 languages.

Sno-o-o-o-ort >:-} Good one! ...Jim Thompson

How are we going to tell if 9V batteries are still good if we can't tongue them?

John ;-#)#

I don't know, but I've got similar voltages. I think we mostly try to stay within the letter of the law, but don't get any certification. (Or if you are small enough can you self certify? Sounds like an oxymoron) We've been selling our diode laser for years. ~120V DC going to a piezo stack. When we started shipping to Europe we added 'security' screws to one end of the DB9 connector so that some idiot wouldn't take it off and stick his finger in there. Hmm I should probably think about adding current limit to the line.... it's got a series resistor but a depletion Fet thing might be better.

George h.

Haw! I love it!

Have you noticed a metallic aftertaste? I think it's nickel ions.

You can self-certify for CE, but not UL.

OK, I think someone (in the EU) wanted a CE mark, and so that's what we did. In the more distant paste there was a German professor who wanted to make sure our Rb lamps passed emission standards. I went with a guy and we ran the tests.. not certified, but just measured stuff, found that there was a bit of radiated gunk above 1 GHz... we made the light hole a little smaller, (actually not a big deal) and then the Prof. didn't even buy one!

George H.

BITD a relative of mine tested a 67.5-V B battery that way. Only once. ;)

Cheers

Phil Hobbs

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Only once. ;)

John ;-#)#

Without seeing the exact UL wording I very much doubt it is an issue about electric shock,

Even for ELV circuits, large currents can do a lot of damage, I would not us rings or metallic watch bands e,g, when working with a ELV forklift battery, Specifying the energy available instead of current available also solves the issues of big (super)capacitors.

At least in EU, there are some situations in which ELV (PELV/SELV) can be "dangerous voltage".

With pretty clammy hands, I grabbed two alligator clips in opposite hands and cranked up the DC voltage. It got pretty bad about 90 volts. I noticed the same metallic taste afterwards.

Some British guys that I worked with in Oxford kindly explained to this dumb yank that CE means Can't Enforce.

Go to Oxford some day. It's a magical place.

When I was 17, I took a year off university and worked in a camera shop, among other things. (I'd goofed off pretty badly in my first year, so I decided to come back to it when I could take it seriously.)

With some of my pay, and an employee discount, I set up a darkroom in my parents' furnace room. It was hot air heat, which stirs up a lot of dust--_not_ what you want in a darkroom. So I attached a hose and nozzle to the drain spigot of the hot water tank, and before using the enlarger I misted down the table, concrete walls, and floor. Worked great. Then one time I reached up to turn on the suspended light bulb in the middle of the ceiling, and couldn't let go. I had to let my knees bend to the floor to pull my hand free. A good thing the wire didn't come down. Needless to say, a very beefy ground wire was attached to the fixture very shortly after.

Cheers

Phil Hobbs

People might confuse it with this tribute band.

Tongue is for 1.5 and 3V batteries. use upper lip for 9V,