In article , Mark Lloyd wrote:
On Thu, 15 Feb 2007 19:07:45 GMT, (Doug Miller)
wrote:

In article , Mark Lloyd
wrote:
On Thu, 15 Feb 2007 02:52:43 GMT, (Doug Miller)
wrote:

In article , Mark Lloyd
wrote:
On Thu, 15 Feb 2007 01:35:28 GMT, (Doug Miller)
wrote:

In article , Mark Lloyd
wrote:
On Wed, 14 Feb 2007 18:29:08 GMT, (Doug Miller)
wrote:

In article , "HK"

wrote:
Thanks everyone. Good information here.

This is a Grade 6 project and I was a little distressed to find that
even
the basic concepts of electricity haven't been taught yet they are
supposed
to build a basic circuit and working model.
For instance, my daughter assumed that to power two 6v lights, she
needed a
12v power supply. Yikes.

So what's the problem? Connect them in series.

Or in parallel if the power supply is big enough. C cells may not be.

If you connect two 6V lamps in parallel to a 12V supply, you're quite
likely
to see the two lamps doing an excellent imitation of fuses -- especially
"if
the power supply is big enough".

I have done that before. They usually do not burn out immediately, but
glow brighter (and whiter) for awhile.

Of course that is not what I was talking about before. Maybe you
missed that what I said was an ALTERNATIVE to using 12V.

?

I was responding to your suggestion, visible above, that "if the power
supply
was big enough" he could connect two 6V lamps in parallel to a 12V supply.


That just might have worked IF I had forgotten what I said, and you
had edited my quote to say that. "12V" does not appear in that quote
at all.

Apparently you *did* forget what you said, or at least you forgot what you
were responding to -- which was the girl's belief that, to light two 6v
lamps, she should connect them to a 12v supply.

*I* said that would work fine if they were connected in series -- which is
true, as each lamp would see 6v.

*You* said "or connect them in parallel if the power supply is big enough".

That won't work for very long.

OK, I left something out (saying to use 6V, or clarifying what "big
enough" means). That's no excuse to stick in something that doesn't
belong.

I didn't stick *anything* in there, and you know it.

I do. That's something that would have helped make it look like I was
saying to use 12V.

You *were* saying to use 12V. Look at the sentences. OP said daughter thought
you needed to use a 12V supply for two 6V lamps. I said not a problem if you
connect them in series. You said "or in parallel."

And that's not correct. Do that, and you'll burn them out.

The discussion to that point had concerned itself only with 12V supplies;
thus, in the absence of any qualifying clauses specifying a different voltage,
subsequent statements must be taken as referring to the 12V supply under
discussion. If you *meant* "or in parallel, using a 6V supply" then you should
have *said* "... using a 6V supply."

I put in the word "OR" at the beginning of the line in question. Did
you forget what "or" means?

I know perfectly well what "or" means -- it means you were suggesting an
alternative. The flow of context makes it very plain that the meaning of your
suggested alternative was to connect them in parallel to a 12V supply, as
opposed to my suggestion to connect them in series.

This was something that would work
INSTEAD of "series and 12V". Why assume I meant something other than
what I said?

I *am* assuming you meant *exactly* what you said. The problem is that you
apparently didn't say what you meant -- if you *meant* 6V, then you needed to
*say* 6V.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.