On Oct 26, 9:45*am, T i m wrote:
On Sat, 25 Oct 2008 21:54:18 -0700 (PDT), wrote:
On Oct 25, 11:33*am, T i m wrote:
On Wed, 22 Oct 2008 05:38:01 -0700 (PDT), wrote:

I was thinking 3 x 4.5V = 13.5V, not far off the float voltage of a
12V battery and as the solar panel isn't going to be dumping 5A in
there it may not pick up much above say 14V. I was thinking these
lights may well deal with that as-is and if not a series diode or two
might just take the edge off it?

way too high a string voltage,

Why?

and you've not taken account of the
wide range of lead acid voltage.

I thought I had?

Bu this has been explained already.

It has, and?

T i m

Will be interesting to see how you plan to run a 13.5v load off a
10-14v battery then.

Ok, well I'll start helping you by asking you some questions.

Re the 3 x 1.5V primary cells and the lamp in general. Will:

1) they start off at exactly 1.5V each?
2) they remain at exactly 1.5V for their entire life?
3) the lamp explode when they run down?

1. some do, some not.
2. no
3. no
4. you're still missing the point


Maybe you're going to build a switched mode boost
regulator, but given your basic questions I doubt it.

Now now, don't start turning into one of those nasty bitter people who
feel they are gods and must be listened to, or want to belittle anyone
who asks a silly question or doesn't 'get' a reply or point. *It's a
*discussion* group about all things d-i-y (and other g) and if you
can't or don't want to help, just don't.

and dont make stuff up. I'm trying to explain to you that theres a
problem. If you disagree, thats fine with me.


In any case, that boost
regulator doesn't sound like it would be as energy efficient, cheap
or simple as my solution so why on earth would I?

It would be more efficient and, more importantly, it'd work.


Cheers, *T i m *

p.s. I nearly bought a pack of 3 such lights in B&Q yesterday (3 for 6
... *quid and they looked good quality) but after selecting them I
later put them back as the 3 checkouts that were open had 50 people in
each queue. :-(

Decent ultrabrights are 20p plus per led, so youre not going to get
owt but tat at those prices for fixtures as well.


NT