? on small battery operated fluorescents

120VAC. See:

Ed

ent

hing

since

so,

uld

and

Do

Unless you have a severe itch to proceed with local parts, I don't see why you'd use that. Also, I hate to see something running off battery power using a linear regulator, unless this project is only about cheapest way with parts you have on hand.

For a replacement to something that lasted 20 years, I think you deserve more. As always, with a simple circuit homebrew product the trickiest part isn't the parts as much as the case, what is reasonable to use instead of being a chunky box when it comes to a flashlight that has to satisfy a significant other.

You have not listed all your design requirements, so there isn't an easy answer. One popular alternative among mountain biking circles is to make the body of the flashlight out of tubular or square/ rectangular aluminum, then the body of the light becomes the heatsink and the driver board, then for handheld use.. plus cells (battery) is contained within. One caveat with this type of design is if the handle is a heatsink, if it runs for a few minutes it starts to get hot at higher current levels. Size becomes one of the design criteria.

When it comes to implementing a driver board and LEDs, the sky is the virtual limit on how you want to shoe-horn these into a finished product if you only keep the cooling vs current requirements per light output in mind. Basically, I suggest you try the modern Cree XR-E LEDs, with a driver board that suits your average voltage for whatever battery you want to use, then as far as the rest of the housing, it's up to your imagination so long as you remember to keep the heatsinking reasonable for the driving current used. More light requires a larger flashlight, though all else being equal, the more LEDs you use, the more investment in buying more per the light output you want, the resultant lower drive current will reduce the size of the heatsink you need since you reduce the heat density per LED. Driving XR-E's at

350MA per seems to be a sweet spot for good efficiency vs cost, but this still requires at least a minimal heatsink.

--
You may have corrected an erroneous assumption he made, and good on you
for that, but so what?

My critique was that you didn\'t answer the question about the tube\'s
_voltage_ requirements, which is what he was looking for.

Certainly, for someone as fluorescent-lamp-savvy as you claim to be,
that data should have been on the tip of your tongue.

--
Geez, I wonder why he didn\'t answer the OP\'s question then?


JF

"John Fields" "Phil Allison"

** That is NOT correct either.

You still have no idea what my post was about.

Cos you will never admit your ridiculous error.

** 100 % BOLLOCKS !!!!!!!!!!!!!!!

There is no possible critique re what was ** NOT ** posted. ---------------------------------------------------------------------

1. It's entirely a matter of choice whether to answer any post at all.
2. It's entirely a matter of choice what issue one choses to address, either arising from or secluded in the wording of any particular post.
3. Congenitally autistic, malignant piles Septic Shit like John Fields get no say on that whatever.

Have a vile death - ASAP.

..... Phil

"John Fields"

** 100 % BOLLOCKS !!!!!!!!!!!!!!!

There is no possible critique re what was ** NOT ** posted. ---------------------------------------------------------------------

1. It's entirely a matter of choice whether to answer any post at all.
2. It's entirely a matter of choice what issue one choses to address, either arising from or secluded in the wording of any particular post.
3. Congenitally autistic, malignant piles Septic Shit like John Fields get no say on that whatever.

Have a really vile death - ASAP.

..... Phil

Aah. Thank you, Ed. Answers that question real easy. Much appreciated.

Dave

"Dave"

** ROTFL

Wot a prize case of the blind leading the blind.

...... Phil

--- Really???

From his post:

"Once purchased a small flashlight with a fluorescent (6") built into the side, and a switch that let you decide which one to turn on. Ran on

4 AA batteries, for several hours."

You replied:

"** That is a 4 watt rated fluoro tube. An inverter to drive it would consume another watt or two. Makes about 6 watts or 1.5 watts per cell - ok ? The published data on Energiser AAs says that their running time at 1 amp is less than 1 hour.

Same goes for C size cells. Only D size cells would hold up for several hours."

Now, to me, that sounds like you were saying that his _assumption_ that the thing would run for several hours on four AA cells was wrong (that would be the "erroneous assumption" I mentioned) and you were correcting him. (That would be the "You may have corrected him" I mentioned).

So how am I wrong?

---

--- Well, it sure wasn't about answering a question that was asked.

But, tell me then, since you seem to think that I'm clueless, what _was_ your post about?

---

--- WTF???????

---

--- No; here it is again:

"My critique was that you didn't answer the question..."

Now how can that possibly be bollocks since you didn't answer his question, and _that's_ what I critiqued?

Methinks your mind may be on overload; careful, you may wind up like this:

--- Agree

---

--- Agree

---

--- Disagree.

From your #2, above, I chose to address the issue of your not answering the OP's question.

You, of course, are at liberty to criticise my choice but, by your own words, have no say on whether or not I may post.

---

--- Spoken like someone behind a vile life.

JF

--- What's next, "Have a really, really vile death - ASAP"?

And then, reductio ad absurdum,

"Have a really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, vile death - ASAP"?

Or will you shout it out in all caps as it seems is your wont, you emotionally crippled moron.

JF

--- Why not post the right answer then, instead of just making things worse?

Ed's a big boy and can stand to be corrected, unlike someone I know...

F'rinstance, how about the filament voltage and current, and the striking and running voltages?

A fluorescent lamp guru like you ought to have that data at your fingertips, yes?

JF

Unless you have a severe itch to proceed with local parts, I don't see why you'd use that. Also, I hate to see something running off battery power using a linear regulator, unless this project is only about cheapest way with parts you have on hand.

For a replacement to something that lasted 20 years, I think you deserve more. As always, with a simple circuit homebrew product the trickiest part isn't the parts as much as the case, what is reasonable to use instead of being a chunky box when it comes to a flashlight that has to satisfy a significant other.

You have not listed all your design requirements, so there isn't an easy answer. One popular alternative among mountain biking circles is to make the body of the flashlight out of tubular or square/ rectangular aluminum, then the body of the light becomes the heatsink and the driver board, then for handheld use.. plus cells (battery) is contained within. One caveat with this type of design is if the handle is a heatsink, if it runs for a few minutes it starts to get hot at higher current levels. Size becomes one of the design criteria.

When it comes to implementing a driver board and LEDs, the sky is the virtual limit on how you want to shoe-horn these into a finished product if you only keep the cooling vs current requirements per light output in mind. Basically, I suggest you try the modern Cree XR-E LEDs, with a driver board that suits your average voltage for whatever battery you want to use, then as far as the rest of the housing, it's up to your imagination so long as you remember to keep the heatsinking reasonable for the driving current used. More light requires a larger flashlight, though all else being equal, the more LEDs you use, the more investment in buying more per the light output you want, the resultant lower drive current will reduce the size of the heatsink you need since you reduce the heat density per LED. Driving XR-E's at

350MA per seems to be a sweet spot for good efficiency vs cost, but this still requires at least a minimal heatsink.

--
sigh  Am just beginning to realize the complexity of what I originally 
imagined to be a simple and quick throw-together.  No easy answers.  Would 
like to make use of some type of flashlight bulb (krypton?) that would 
tolerate the 18V my battery pack offers when fresh, and would continue to 
function in some fashion as it dropped down below 12V.  Would also like to 
run an 8-watt fluorescent off of the same battery pack as long as possible 
(Possibly this one?
http://www.newark.com/cec-industries/f8t5-cw/fluorescent-lamp/dp/85K9048?_requestid=96321).

Would *like* to make use of the same battery pack I am currently using 
simply because it fits the hand well and represents the *approximate* 
desired finished size (+/- 8" x 1.25" x 1.25").  Would like to run the 
fluorescent down one side of this battery back.  I imagine sealing the 
electronics in the insulative,  industrial sealant/craft adhesive E-6000, 
leaving whatever heatsink is necessary outermost on the end away from the 
flashlight bulb/reflector.  Would like to use a three-position rocker switch 
to select between the two lighting functions.

What, in your opinion, would be the best way to achieve the 120VAC required 
by the aforementioned fluorescent bulb for as long as possible?  Stick with 
a 12VDC regulator, and run the output through a switching power supply for 
X10 output?

You mentioned Cree XR-E  LEDs.  The Q5 does look promising.  Is this the 
5-watt LED that I hear about at  my electronics candystore?  And what, 
actually, is involved in designing a driver board?  Would these compare at 
all with a Krypton bulb?  Or is that simply a trade-off one weighs, 
brightness for current drain?

All I can think of right now.  Really appreciate your patience, and help. 
Sorry for the long-drawn out post...

Dave

Use white LEDs. Much easier. She won't know the difference.

John

In fact, I appreciate it. :-) If the datasheet is wrong, then others could benefit, too. And if Phil can provide missing data, so much the better.

Ed

True, even trying to recreate a $2 plastic 2D flashlight takes a lot of time relative to what you end up with. The more partially if not wholly finished parts you dig up, the less time and expertise it will require. You might want to look at the various bits and pieces at one of the sites I mentioned previously, see if they give you any ideas.

Depends on what "in some fashion" means, a bulb optimal for 18V won't be nearly as bright at 12V, and while I'm sure somebody makes 18V bulbs they're quite a bit rarer than 12V, limiting your choices and/or raising cost, plus a good result over this operational voltage range would require a regulated supply. I would think about using an LED for this too, with optics or a reflector, or both, for the tighter beam you're probably seeking.

Previously it was 4 x AA, presumably something like the following might've worked (though it's spotlight probably uses a lower powered, less bright LED than the LEDs I was previously writing about),

but now 18V? Was this an RC toy or drill battery? It seems a big jump in voltage compared to the small handheld flashlights I thought we were talking about. If you want 18V the solution is easier, get a ready-made flashlight that comes as close as possible to your needs from a hardware store, something made for cordless drills. When they have a fluorescent tube in them they tend not to have the incandescent spotlight too, or vice-versa, but if you're wanting an 18V light I doubt the end use will be the same as what I was envisioning previously.

e

nt-lamp/dp/85K9...).

I could be wrong, but am starting to think this flashlight will end up taking at least a dozen hours and maybe $75 or more. Seems like a great length to go to, to reinvent the wheel when there are so many flashlights out in the market.

0,

witch

ed

with

r

In my opinion you have several project targets that make it unreasonably laborious and expensive to end up with a flashlight. It'll end up costing multiple times as much as a finished product, be no more reliable (except maybe the switch if you use a good quality one), and will use a battery pack that already has wear on it when a finished new product may come with a brand new pack.

To DIY, I would not use a buck regulator (letalone linear, it'd be far too lossy/large a heatsink) to go down to 12VD then back up to 120V, instead you'd want a rare 18VDC to ~ 120VAC booster. Well I wrote rarer but here's the irony: The best place to find one of those is to buy a finished cordless drill pack compatible 18V flashlight then take the driver board out of it, but it seems a bit backwards when it's a whole finished flashlight already.

GEKGM.htm (or just buy the whole kit with battery and charger, then you're 100% set).

s the

Up to 3W, driven lower they have higher efficiency. IF you just wanted to throw this together cheap, you could just put 4 of these in series on your 18V pack, then calculate out a suitable current limiting resistor for the series. I prefer proper LED drivers but they start costing a lot more if in an odd voltage like 18V, or maybe even higher peak voltage if that is spec'd as an 18V rechargable pack?

Same as any other circuit? Pick a driver IC (which for this load wouldn't need external switching transistors, would have it integrated), study the datasheet, refer to the examples and calculate out the support parts' specs you need to get from point a to b. Generally you'd be looking at an IC that has an internal reference voltage that is compared against a small drop across a minimal value resistor, to regulate the current through the load (LEDs). So you'd typically have up to a half dozen small heat resistant capacitors, fewer resistors, an inductor, plus the board/wires/connectors/etc.

LEDs will be multiple times brighter at any current drain you select, so long as you don't pick a terribly lossy way to drive them like a linear regulator or dropping too much with a series resistor, and don't overdrive them very excessively, instead adding more LEDs instead of more current per LED. A single 3W LED driven at that (3W), will be brighter than the typical krypton flashlight bulb, but there are so many sizes, shapes, ratings for a bulb it really depends on exactly what you're comparing to, and for the intended use you'll have to pick the best optics or reflector.

p.

I would pick one of two paths trying to meet all goals as much as possible. Either buy a finished product that comes closest to your needs, or mount about 4 Cree XR-E on a piece of 1" square aluminum tubing (about 3/32" or thicker walled) and give them 500 to 750mA in series off your 18V pack. See how that looks, and if the tubing stays cool enough for the application. LEDs are fun to play around with, at worst if you don't think they're suitable there's bound to be something else you can put them in, like a different flashlight, undercabinet lighting, automotive use, or something similar.

"John Fields"

** It was not an " assumption" - f****it.

He made a **claim** that appears to be impossible.

So that claim needed to be addressed.

** 100 % BOLLOCKS !!!!!!!!!!!!!!!

Cos there is no possible critique re what was ** NOT ** posted.

The matter I raised needed to be cleared up before going further.

The OP has posted no response.

Cos his claim was bullshit.

-------------------------------

1. It's entirely a matter of choice whether to answer any post at all.
2. It's entirely a matter of choice what issue one choses to address, either arising from or secluded in the wording of any particular post.
3. Congenitally autistic, malignant piles Septic Shit like John Fields get no say on that whatever.

Have a vile death - ASAP.

..... Phil

"John Fields Has Gone INSANE "

** Do not deal with is INSANE person.

Fields is one congenitally autistic, malignant pile of Septic Shit.

Hope he has a vile death - ASAP.

..... Phil

"John Fields Has Gone INSANE "

** Do not deal with is INSANE person.

Fields is one congenitally autistic, malignant pile of Septic Shit.

Hope he has a vile death - ASAP.

..... Phil

--
And the reason he made the claim was because he _assumed_ it was
correct.