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.

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

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