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dmatthew.carter@gmail.com: May 20 03:18PM -0700 I purchased a 3 pack of the model 350 at Costco. Everyone one of them has this issue. 3 months is about right. Put new batteries in all of them and a few months later they all are virtually drained of battery life.   Matt C

Jon Elson <elson@pico-systems.com>: May 20 05:23PM -0500 On Mon, 20 May 2019 15:18:29 -0700, dmatthew.carter wrote:   > has this issue. 3 months is about right. Put new batteries in all of > them and a few months later they all are virtually drained of battery > life. Well, of COURSE! The purpose of selling a flashlight is to sell BATTERIES! If you can design the flashlight to DRAIN the batteries, then you sell more batteries! What a brilliant concept.   Does this thing have an electronic circuit to turn the light on and off? Maybe that circuit has some small current to keep it operating.   Jon

Jeff Liebermann <jeffl@cruzio.com>: May 20 06:56PM -0700 On Mon, 20 May 2019 15:18:29 -0700 (PDT), dmatthew.carter@gmail.com wrote:   >in all of them and a few months later they all are virtually >drained of battery life. >Matt C   That would be a Duracell Durabeam Ultra 350. The current version sold by Costco is the Durabeam Ultra 380, which is the same flashlight package except all 3 flashlights are black. I would guess(tm) that the 350 was last sold in early 2017, so you probably bought "old stock" that was sitting on the shelf for about 2 years. <https://costco97.com/duracell-led-flashlights-3-pack/>   A unique feature of these Duracell line of flashlights (350, 380, 500) is that they use FOUR alkaline cells instead of the usual three. This is an attempt to squeeze more lumens out of the flashlight at the expense of battery life. The driver (current regulator) chip used may have been originally designed to run at 3.0 to 4.0v for one LiIon, and maybe 3.9 to 4.8v for three alkaline cells, but might have problems with 5.2 to 6.4v for four alkaline cells. My guess(tm) is that these lights used the usual AMC7135 current regulator IC which is rated at 350ma from 2.7 to 6.0v. <https://www.electroschematics.com/wp-content/uploads/2016/04/acm7135-datasheet.pdf> In my limited experience tinkering with some of these chips, I found that 6.0v really is the absolute maximum voltage that can be used and that some (not all) chips will blow up at around 7v. Running these on 4 alkaline cells seems a bit close for comfort. Unfortunately, I did not check for leakage current through the driver. It's easy enough to do. Install 4 brand new alkaline cells and measure the current drain when off. If you measure any leakage current, you can guesstimate the standby life of the battery by dividing the capacity of a single cell by this current. For example, if you measured 0.1ma of leakage, all four AAA cells will be depleted in: 750ma-hr / 0.1ma = 7,500 hrs which equals: 7,500hrs / 24 hrs/day = 313 days or about 1 year. Based upon your 3 month experience, and that the package was probably sitting on the shelf for a while, I would guess(tm) you should see about 0.35ma of leakage.   However, all is not lost. There are LiIon inserts made to fit in place of alkaline battery holder. This is commonly done with flashlights that take 3 alkaline cells: <https://www.youtube.com/watch?v=yNo_k_LOWMM> It can also be done with an 18500 LiIon cell, if you can find one. I've done much the same thing except I used a hard rubber chemistry cork instead of a wine bottle cork. However, I haven't seen anything for doing it with 4 alkaline cells. That's probably a waste of time, so I suggest you recycle the flashlight and buy something that runs on a LiIon cell and not on alkaline cells.   -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann <jeffl@cruzio.com>: May 20 07:25PM -0700 On Mon, 20 May 2019 18:56:59 -0700, Jeff Liebermann <jeffl@cruzio.com> wrote:   >lights used the usual AMC7135 current regulator IC which is rated at >350ma from 2.7 to 6.0v. ><https://www.electroschematics.com/wp-content/uploads/2016/04/acm7135-datasheet.pdf>   Duh. Maybe I should have looked at the data sheet before I continued to guess. See graph on Pg3 "QUIESCENT CURRENT vs. SUPPLY VOLTAGE". The graph only goes to 4.1v which is a subtle hint that 6v might be a bad idea. They could have used two or three AMC7135 chips in parallel to obtain the necessary current handling, but then the leakage current would be 2x or 3x as high. Killing the batteries with this leakage current in 3 months is quite possible.   However, much depends on whether the Duracell Durabeam Ultra 350 uses an AMC7135, and whether power is always applied to the AMC7135. I can't tell from here without disassembling the flashlight, reverse engineering the schematic, and making a few measurements.   Deconstructing a flashlight: <https://kandepet.com/deconstructing-a-flashlight/>   -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

tabbypurr@gmail.com: May 21 02:01AM -0700 On Tuesday, 21 May 2019 02:57:08 UTC+1, Jeff Liebermann wrote: > >in all of them and a few months later they all are virtually > >drained of battery life. > >Matt C   ... > for doing it with 4 alkaline cells. That's probably a waste of time, > so I suggest you recycle the flashlight and buy something that runs on > a LiIon cell and not on alkaline cells.   or use NiMH     NT

Look165 <look165@numericable.fr>: May 21 11:36AM +0200 I think NiMH is 1.2V while cells are 1.5V.

Jeff Liebermann <jeffl@cruzio.com>: May 21 09:29AM -0700 >> a LiIon cell and not on alkaline cells.   >or use NiMH >NT   Yep, that will work better than alkaline. 800ma-hr for NiMH instead of 750ma-hr for alkaline. The actual difference will be larger because NiMH tolerates high current loads better than alkaline.   I'm partial to LSD (low self discharge) NiMH cells. About $2.50/cell from China: <https://www.ebay.com/itm/400827732093> or $4.00/cell from USA vendor: <https://www.ebay.com/itm/153458804452> Four cells per flashlight would cost $10 to $16 per flashlight. For that price, I could buy an equivalent LiIon flashlight, and still have some money left over for a crude LiIon charger. Most of these: <http://www.learnbydestroying.com/jeffl/crud/LiIon%20Flashlights.jpg> were $5 to $10/ea plus charger.   I forgot to mumble something about the leakage current. Because the on-off switch is usually in series with the battery, the "off" leakage current should be zero. Yet, the Duracell Durabeam Ultra 350 flashlights seem to be leaking some current. Therefore, my guess(tm) is that the flashlight is wired in a somewhat different manner. Since the purpose of this flashlight is to sell more AAA batteries, I wouldn't put it past Duracell to put something across the switch or use a different wiring configuration to produce some leakage current.     -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

tabbypurr@gmail.com: May 20 10:19AM -0700 On Monday, 20 May 2019 13:40:53 UTC+1, John Robertson wrote:   > would last within X%? Wire wound resistors external connections were > pressure bonded to the resistance wire, not uncommon for that joint to > fail over time...   I presume you mean carbon composition rod. Pure carbon would give too few ohms to have much use in a valve radio.   Some Rs used metal caps instead of wires, and were mounted in a clip-in holder. I guess they needed to be replaced sometimes as different valves sometimes needed different grid leak values.     > over time. Modern Rs are much more reliable when operated under their > rated wattage.   > John :-#)#   as long as it's well under. Rated life for power Rs operated at specced power can be terrible.     NT

Cursitor Doom <curd@notformail.com>: May 20 10:46PM On Mon, 20 May 2019 08:11:31 +0100, Mike Coon wrote:   >> Trying to keep hydrogen in or out is always problematic.   > In practice you get molecules on the two-fer principle which are much > bigger. Helium is bad too because then the atoms come at you singly...   May seem counter-intuitive, but hydrogen is not actually the smallest atom. Heliums come singly alright, which is one of the reasons, along with small size, they're used for this kind of leak testing.       -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition.

whit3rd <whit3rd@gmail.com>: May 21 12:08AM -0700 On Monday, May 20, 2019 at 3:46:16 PM UTC-7, Cursitor Doom wrote:   > May seem counter-intuitive, but hydrogen is not actually the smallest > atom. Heliums come singly alright, which is one of the reasons, along > with small size, they're used for this kind of leak testing.     Good point; also, the H2 molecule has two 1S-like electrons, which is very similar to a Helium atom, and just about as slippery. H2 atoms are lighter than He, on average.

whit3rd <whit3rd@gmail.com>: May 21 12:09AM -0700 On Monday, May 20, 2019 at 3:46:16 PM UTC-7, Cursitor Doom wrote:   > May seem counter-intuitive, but hydrogen is not actually the smallest > atom. Heliums come singly alright, which is one of the reasons, along > with small size, they're used for this kind of leak testing.     Good point; also, the H2 molecule has two 1S-like electrons, which is very similar to a Helium atom, and just about as slippery. H2 molecules are lighter than He atoms, on average.

John Robertson <spam@flippers.com>: May 21 08:04AM -0400 >> pressure bonded to the resistance wire, not uncommon for that joint to >> fail over time...   > I presume you mean carbon composition rod. Pure carbon would give too few ohms to have much use in a valve radio.   Thanks, I did mean composite.     > Some Rs used metal caps instead of wires, and were mounted in a clip-in holder. I guess they needed to be replaced sometimes as different valves sometimes needed different grid leak values.   Ads in the early radio magazines are handy for that sort of data. And yes, you did keep a drawer of grid resistors handy if you wanted best performance out of your rig.     >> John :-#)#   > as long as it's well under. Rated life for power Rs operated at specced power can be terrible.   > NT   Power derated curve curves can be surprising for almost any component.   Heck Molex pin connectors are rated at 25 insertions if I recall correctly, and they are heavily used in arcade games...   Spec sheets do need to be read after all.   John :-#)#

Ralph Mowery <rmowery28146@earthlink.net>: May 21 10:20AM -0400 In article <1c3fb9af-1eba-4642-92da-dc860731b861@googlegroups.com>, whit3rd@gmail.com says...   > Good point; also, the H2 molecule has two 1S-like electrons, which is > very similar to a Helium atom, and just about as slippery. > H2 atoms are lighter than He, on average.   Hydrogen is also explosive or will burn. That is another reason not to just spray it out for leak detection.   I think that hydrogen may be the smallest atom, but they often join in pairs to make up a larger molicule. Some other atoms that are normally gas do the same thing.

makolber@yahoo.com: May 20 11:47AM -0700 I think the OP was asking a simple question about powering the 12 v clutch using the 6 volt supply from the tractor AND a 6 volt battery in SERIES.   YES, that will work fine.   If you want to get fancy you can hook up a DPDT switch so the 6 V battery is charged by the tractor when the battery is not being used to power the clutch.   mark

Fox's Mercantile <jdangus@att.net>: May 20 04:28PM -0500 > I think the OP was asking a simple question about powering > the 12 v clutch using the 6 volt supply from the tractor > AND a 6 volt battery in SERIES.   That's what I wrongly assumed to begin with. What he wanted to do is switch the 6 v generator in series with the battery to total 12 volts.   In retrospect, this is a problem as one side of the generator is grounded. Kind of hard to float it in series.       -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

etpm@whidbey.com: May 20 02:30PM -0700 >YES, that will work fine.   >If you want to get fancy you can hook up a DPDT switch so the 6 V battery is charged by the tractor when the battery is not being used to power the clutch.   >mark Actually I was thinking of using the tractor generator is series with the existing tractor battey, not an extra battery. Eric

Wolf Bagger <wolfbagger@pm.me>: May 20 11:42AM -0700 On 2019-05-18 14:28, Arlen G. Holder wrote: > <paranoia>   Is corporate mind control the new Government mind control?

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