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Post by leonski on Sept 27, 2022 13:59:14 GMT -5
For AA and some other common sizes? You might consider some of the rechargeable options. They do not last as long in service before needing recharge, BUT also do not leak.
I have a handheld device (GPS from Garmin) which even has a setup option for them......The Eneloop 'brand' is very well made and my walwart says Panasonic.....I bought 4x of the AA and
marked 2 batteries so I could keep them in pairs......
I see TV ads for 'wireless home security cameras'. NO mention made of battery change frequency or the idea of lots of ladder work to keep 'em working. And the expense, of course.
If I ever installed a home security system? WIRED with battery backup in one central location...
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Post by leonski on Sept 28, 2022 15:04:54 GMT -5
One OTHER battery 'thing'.
Tesala cars use (or did, anyway) the 18650 LionCell. This is 3.7 volts and from 2000mah on UP......I don't know what the current real limit is.
They used a MOUNTAIN of these guys and for a commodity battery? Very well done.
But I was thinking that for POWER TOOLS which are incorrectely rated at volts? The 18650 would be a terrific choice. 10X would be 37 volts and
a lot of 'watts' whichis what really matters. They are a lighter battery than NiCad so the entire pack might not be much or any heavier than those.
I see a lot of 20v tools......3 of the 18650 in series.....while 36 volt is available. Higher? I don't know. I'd make a cordless tool with a BELT PACK
power supply and keep the tool lighter while going for maximum capacity. 2 packs SHOULD get you thru an entire day of whatever?
I have an 18650 FLASHLIGHT. One cell. And it is only a 2000mah capacity. But the light is awful bright and lasts for hours. It can be focused, too,
from 'spot' to wider area. A real beast of a flashlight.
Buiilt in dimmer if used would double lifetime. It has a RED light, too....along with an array of LEDS used for wide area illumination....but close.....like in a tent, maybe.
Bring a spare or 2 for a weeks camping?
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Post by garbulky on Sept 28, 2022 16:09:11 GMT -5
One OTHER battery 'thing'. Tesala cars use (or did, anyway) the 18650 LionCell. This is 3.7 volts and from 2000mah on UP......I don't know what the current real limit is. They used a MOUNTAIN of these guys and for a commodity battery? Very well done. But I was thinking that for POWER TOOLS which are incorrectely rated at volts? The 18650 would be a terrific choice. 10X would be 37 volts and a lot of 'watts' whichis what really matters. They are a lighter battery than NiCad so the entire pack might not be much or any heavier than those. I see a lot of 20v tools......3 of the 18650 in series.....while 36 volt is available. Higher? I don't know. I'd make a cordless tool with a BELT PACK power supply and keep the tool lighter while going for maximum capacity. 2 packs SHOULD get you thru an entire day of whatever? I have an 18650 FLASHLIGHT. One cell. And it is only a 2000mah capacity. But the light is awful bright and lasts for hours. It can be focused, too, from 'spot' to wider area. A real beast of a flashlight. Buiilt in dimmer if used would double lifetime. It has a RED light, too....along with an array of LEDS used for wide area illumination....but close.....like in a tent, maybe. Bring a spare or 2 for a weeks camping? Link to flashlight? |
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Post by leonski on Sept 29, 2022 2:37:25 GMT -5
I've found the battery. It is an ODD version of the 18650 in which both terminals are on ONE end. A ring surrounding a disc......
Other end is insulated.
Flashlight is a Gen1 NEBO Slydeking or whatever.....An expensive light. A new battery will go me 10$ and I think the local battery house has one at that price.
Too bad all I can get is 2000mah, not one of the higher capacity in the same size.....
I'll keep this until it simply fails in service. Waterproof, too. Heavy but an amazing amount of light......
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KeithL
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Post by KeithL on Sept 29, 2022 11:10:21 GMT -5
Yeah.... now "everyone is a photographer" (just, sadly, not necessarily a good photographer). Cell phones nowadays have high-megapixel sensors which helps... They also do lots of "pixel math" - what we would normally consider post-processing - but it's done at the "RAW" level. (They do fancy things like shifting and then averaging the pixels on a high-res image to make a lower res image.) Because of this they can deliver pictures that look impressively good - until you look too close or try to post-process them. My middle-of-the-line Samsung Galaxy S20 claims 64 mega-pixels... But the best it can actually deliver is "pretty sharp with bright daylight"... And the pictures get really soft in dim light... (They're legible, and they look good on a phone screen, but pretty sad on a real screen). I don't know about the sensor size - but the biggest of the three lenses looks to be about 1/16" in diameter. I've looked at DxO Photolab - and it looks quite nice (their PureRAW looks interesting too... and I've heard that it does really excellent noise reduction) It's just that, at this point, I've gotten used to the Topaz Labs plugin set... (I tend to be a technology nut... so I sort of collect cool plugins... even though I haven't actually taken many pictures lately.) Another interesting company is Retouch4Me (retouch4.me) . They make plugins that automatically detect and mask very specific flaws - like "blemishes on portraits" and "veins in whites of eyes" and "teeth that aren't white". So, for example, it will automagically detect and mask all the blemishes, but rather than correct them it creates a mask. You can then go into Photoshop and edit the mask to decide which ones to correct and which ones to leave along. (I don't have an excuse to get either of those since I don't take portrait shots.) MP3 is an interesting subject... With some sources it works pretty well... with others not so good... Trivia: The MP3 DECODER is supposed to be standardized... so, with a few exceptions, like top rate supported, "any decoder can play any MP3 file". And a given file should sound very much the same when played on any proper decoder. But the MP3 ENCODER is NOT totally standardized... The output format is standardized so the file it delivers will play on any decoder. But the choices it makes about what to discard to save space is somewhat negotiable. Because of this, an MP3 file made using the same settings, on different encoders, may sound slightly different... And it's actually possible for a particular encoder to be optimized for specific types of content... (There actually used to be a program that would encode your file on several different encoders... then let you pick the version you liked best for each.) It was always my experience that most MP3 files sounded pretty good... But there were a few specific songs that just never came out good at all on any encoder... Nowadays I have plenty of space so I just stick with FLAC... Keith. I just make a General Rule....which may or may not have exceptions. And I must say that everything you mention is 'experimental' and would require a LOT of critical listening to hear what may be minor 'upgrades'. Yes. an entire DIVISION at the Del Mar Fair is devoted to cell lphone photography. Which for vacation 'grabs' is good, but the ruin of real photography. It's all emulsified and few fine differences. I won't beat this to death, but I've made copies and shot same (similar) but at same time images with cell and 'real'. GLASS makes a huge difference and NO cell phone can match 2500$ worth of Nikkor Zoom. I use DxO Photolab and it has a few really powerful helps. If you are at all curious? Download the trial version and than PM me with questions..... As for MP3? I top-out at MP3-160 as a good compromise between memory glut and quality. And use it in the GARAGE system (maybe 100$ worth) or the car. |
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KeithL
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Post by KeithL on Sept 29, 2022 11:42:22 GMT -5
Just remember to include sufficient heat sinks... 78xx are linear regulators... For dropping 12V to 5V at 1 amp that would be 7 watts of heat to get rid of. Not that it helped?? My Cambridge Audio DACMagic+ came with a 24watt (2amp / 12v) wall wart. I thought it was getting flakey and sent off (about 20$ or less) for a Meanwell 12v 3amp = 36 watt. Nice..... And with a 78xx regulator I suppose I could knock it down to 5v or maybe 9v at one amp for other purposes....... I thought I saw someone around here with the Goldenear in their 'equipment' call out.......  ?? |
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KeithL
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Post by KeithL on Sept 29, 2022 11:44:38 GMT -5
Especially with a low current device like a remote control - use the Ultimate Lithiums. They're expensive, but they last a really long time, and don't ever seem to leak. The only way to preemptively prevent battery leakage would be to: 1. Use the same (good grade) of batteries and 2. Change the batteries on a routine interval (in advance of credible failures) If you wait until the device stops working (as I did) you can’t predict whether the leakage has already occurred or not. |
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Post by Boomzilla on Sept 29, 2022 11:56:28 GMT -5
Especially with a low current device like a remote control - use the Ultimate Lithiums. They're expensive, but they last a really long time, and don't ever seem to leak. In general, this might be true. But in these specific lights, I have USED Ultimate Lithiums and they lasted exactly six months - same as the alkaline batteries. No, I'm not mistaken. Good, fresh, new Ultimate Lithiums = 6 months until dead. Costco Alkalines = 6 months until dead. Since I can buy 48 Kirkland alkaline AAA batteries for $18.99, and Ultimate Lithiums would cost $120 at Walmart, I think I'll save the $100 and use it on something else. |
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Post by leonski on Sept 29, 2022 14:29:38 GMT -5
Keith. It is VERY VERY true that all people who take photos are NOT photographers.
But I've heard it's ALSO true that more than 1/2 of ALL photos ever taken (starting in the mid-1800s?) have been take WITH a cell phone.
I have been asked.....more than once......'what camera do you recommend?' I ask some questions back about intended use (pro sports? Kids? weddings? Studio?) and level of background.
At one point years ago I'd recommend you start with FILM. This when good used gear was still available. I'd also recommend taking a college course in Composition.....usually taught thru the Art Department.
Such a course MIGHT be called 2-D design or some such. Film? Obsolete, right? Well.....yes and no. If you want to learn, it is good to SLOW DOWN THE PACE. If you have 24 or 36 exposures......you will
easily be able to parse thru them and determine what is good......maybe with a little help from a mentor. But going thru 300 shots from a wedding? I would routinely take 600 shots. That's ONE a minute for
about 10 hours. And end up with a 100 to 150 shot album AND some very enlargeables.
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Post by leonski on Sept 29, 2022 17:51:42 GMT -5
Especially with a low current device like a remote control - use the Ultimate Lithiums. They're expensive, but they last a really long time, and don't ever seem to leak. In general, this might be true. But in these specific lights, I have USED Ultimate Lithiums and they lasted exactly six months - same as the alkaline batteries. No, I'm not mistaken. Good, fresh, new Ultimate Lithiums = 6 months until dead. Costco Alkalines = 6 months until dead. Since I can buy 48 Kirkland alkaline AAA batteries for $18.99, and Ultimate Lithiums would cost $120 at Walmart, I think I'll save the $100 and use it on something else. IF you use AA or other 'regular' sizes.....this excludes stuff like the 1/2AA and other fractional sizes.....which for some reason still exist.......I'd go to rechargeable. I have my Eneloop which will long-term SAVE money. Even if you up your change interval.......from say.....6 months to 4 or 5? By the time you're done, you'll have saved a bunch. It costs pennies to recharge 'em..... Eneloop PRO is a high-self discharge type and useful IF you need the extra capacity and USE the device frequently. www.costco.com/duracell-ion-speed-4000-rechargeable-battery-kit-with-4-x-aa-batteries-and-4-x-aaa-batteries.product.100671936.htmlBe aware that NiMh CAN have a high self-discharge which makes 'em less than suitable for low drain use. They will self-discharge faster than the device uses them. Buy LOW SELF DISCHARGE or maybe rechargeable lithium...... The problem with Lithium is a personal one with me. I can't keep all the different chemistries straight. |
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KeithL
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Post by KeithL on Sept 30, 2022 8:40:38 GMT -5
Pretty much each type of rechargeable battery has advantages and disadvantages... NiCds have a very high self-discharge rate. The older ones would literally drain completely in as little as a few days if not used. They also tend to be quite heavy and bulky relative to their power rating. (They've become difficult to get because cadmium is now considered to be a very toxic substance to manufacture with and dispose of.) But, unlike other more modern types of rechargeables, you can literally trickle charge NiCds INDEFINITELY without damaging them. So, in something like an emergency exit sign, you simply allow them to charge all the time, at a specified low rate, and they will always remain fully charged. (This is called "trickle charging".) NiCds also work very well at very low and very high temperatures. And many of them can deliver large amounts of current when asked to do so. But they do usually eventually die from age or repeated charge/ discharge cycles. Incidentally you should NEVER put other types of batteries in an older device designed specifically for NiCd cells. The simple chargers used for NiCds only DO NOT shut off and so WILL damage any other type of rechargeable battery - or may even cause them to explode.) NimH batteries are very light relative to the amount of power they store. However, they must be charged carefully, by an "intelligent" charger, because they will be damaged if overcharged. They also have efficiency issues at relatively low or high temperatures. In the old days, if you did outdoor photography, you literally had to keep your spare NimH batteries in your pocket to keep them warm. At the sort of temperatures they might see in a car glove box they can lose MOST of their storage capacity and become VERY slow to recharge as well. I used quite a few of these in the past and I also found them to be quite unreliable. (They would quite often "just suddenly die" or go from "full charge" to "no charge".) Liion batteries are generally far better... They can also deliver a lot of current and some are rated to be able to charge very quickly. However they come in a variety of different formulations - some of which act very differently. And SOME formulation types have a well documented tendency to burst into flames if overcharged or charged incorrectly. (Most laptop battery packs include protection against this - but the single cells used in flashlights and phones generally do not). Pretty well ALL newer types of batteries after NiCds require some sort of "intelligent charger" that detects when they are fully charged and shuts off. This can also be an issue because some chargers that aren't especially well designed can be "tricked" if the power flickers and end up overcharging the batteries. (WIth NiCds and Lead ACid batteries the voltage rises when they are fully charged... with some other types full charge is indicated by a tiny drop in voltage.) In general, this might be true. But in these specific lights, I have USED Ultimate Lithiums and they lasted exactly six months - same as the alkaline batteries. No, I'm not mistaken. Good, fresh, new Ultimate Lithiums = 6 months until dead. Costco Alkalines = 6 months until dead. Since I can buy 48 Kirkland alkaline AAA batteries for $18.99, and Ultimate Lithiums would cost $120 at Walmart, I think I'll save the $100 and use it on something else. IF you use AA or other 'regular' sizes.....this excludes stuff like the 1/2AA and other fractional sizes.....which for some reason still exist.......I'd go to rechargeable. I have my Eneloop which will long-term SAVE money. Even if you up your change interval.......from say.....6 months to 4 or 5? By the time you're done, you'll have saved a bunch. It costs pennies to recharge 'em..... Eneloop PRO is a high-self discharge type and useful IF you need the extra capacity and USE the device frequently. www.costco.com/duracell-ion-speed-4000-rechargeable-battery-kit-with-4-x-aa-batteries-and-4-x-aaa-batteries.product.100671936.htmlBe aware that NiMh CAN have a high self-discharge which makes 'em less than suitable for low drain use. They will self-discharge faster than the device uses them. Buy LOW SELF DISCHARGE or maybe rechargeable lithium...... The problem with Lithium is a personal one with me. I can't keep all the different chemistries straight. |
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Post by Boomzilla on Sept 30, 2022 10:55:03 GMT -5
So if I understand the above, KeithL, there is no such thing as a "universal charger." You have to match the chargers to type of batteries you're charging (and by battery type - not just by battery size). I may be mistaken, but I've read that rechargeable batteries also do best if they're used in the specific charge/discharge range preferred by their technology. Some batteries do best if fully discharged prior to recharging - others do best if maintained between a certain range of charge. I notice that the batteries in my hybrid car, for example, are maintained by the car's charging system in a very narrow charge range. |
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Post by leonski on Sept 30, 2022 14:50:49 GMT -5
Right......NO universal charger.
I have one for car batteries......Lead / Acid of various types
One for my NiMh stuff. My old Canon charger had a DISCHARGE cycle to drain battery prior to recharge. And it had 2 pigtails so it would
sequentially charge / discharge a PAIR of batteries. Perfect at a wedding. Which the night before I'd fix so I had 3 good batteries.......
Camera was HIGH draw and the 10xcell AA pack would last maybe a couple hundred exposures. I could use 2 or 3 packs for a wedding.
And? Canon got 100$ EACH for 'em.......So I ended up going aftermarket at a substantial savings.
And another for the stuff for my model airplane....a Lithium formulation.
Tesla (the Musk folks) ahve gone thru several iterations of chemistry.
just Look UP LION chemistry. Several viable formulas, which may or may not have the same voltage.....Most frequently seen is the 3.7 volt types. Or multiples thereof.
MOST NiMh are high self discharge. THAT is the real Achielles Heel of that type Some LSD types are out there, but NOT for older applicaitons....like my old Canon EOS-1d MK11
That's why Keith notes it'd go 'flat' nearly without notice. My aftermarket batteries were sensitive to contact health. In cold weather? INTERNAL resistance of these cells might
generate enough heat to keep 'em working. Let it sit? Well, let's just say that outdoor types with this battery should keep it IN THE SLEEPING BAG at night!
I weighed my ONLY example of an 18650. 3.7 volts and 2000mah capacity. This is 7.4 watt/hours or about 75 watt hours per POUND. There are higher capacity versions available, though
so you might get a much higher value......If the ratings are not 'cooked'......These cells weigh around 45 grams each.
So? A 40lb LIon battery might have about 40lb x 75wh per pound or 3000wh......While a conventional lead /Acid type might also go 40lb but be maybe 100 amps @12.5volts.....or 1250wh......
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Post by Boomzilla on Oct 2, 2022 13:23:46 GMT -5
Comments from my audio amigo, Russell: On the Appreciation of Digital Music My conversion from analog to digital music began in 1990. I have moved from experimentation with CD players to the ripping of CDs and then SACDs. The ripped content has been stored on various types of hard drives, Secure Digital (SD) cards, and USB thumb drives. Experimentation has given me information on which options sound the best in my system. I receive greater musical enjoyment from digital music collecting than in dealing with vinyl record noise problems. Having a ripped digital collection also eliminates the possibility of transport issues and laser wear on CD players. I prefer having music that I own outright. If I were paying fees to TIDAL , Qobuz, or other streaming services, I’d be concerned not only about file quality but also about prices that are going up every year. By owning the music I listen to, I can control the quality and annual pricing is not an issue. I find that iPad control is a must for seeing and finding my music. Living with this level of convenience, I couldn’t go back to playing discs on a CD player using a remote control. Even sitting behind a computer screen with a mouse isn’t an acceptable substitute. The touch-screen convenience of the iPad is addictive. And finally, I find high value in owning properly designed, time-aligned, and phase-coherent speakers. These design features are more important to digital playback because their benefits are far more audible. Speaker investment will provide greater dividends than money spent on steamers, DACs, and cables. In fact, I’d recommend that you put your money where it counts the most – on your room and on your speakers. |
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Post by leonski on Oct 3, 2022 1:17:37 GMT -5
I TEND to agree to a large extent with Russell.....But my connection to Digital started about a month or so after the FIRST CD players went on sale in this part of the world
I still have my Magnevox FD-1000 which is a rebranded Philips player of the first generation. 14 bit and ALL. Call it about 1983. I still have my First 3 CD purchases, including
The Blues Breakers. Eric Clapton and John Mayall.....
maggies are somewhat time-aligned by design. Being planar, a wide range (frequency) impulse comes out of all drivers simultaniously. Toe can make up for the slight crossover time delay.....
But my disagreement? I believe in Source First.....but that's just me...
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Post by Boomzilla on Oct 3, 2022 14:49:47 GMT -5
Unless I’m mistaken, Magnepans use a second-order crossover (12 dB / octave) between their woofer and tweeter panels. To avoid having a frequency dip at the crossover frequency, the woofer & tweeter panels are wired 180-degrees out of phase. Although Maggie’s are no less, they are NOT phase-coherent.
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Post by leonski on Oct 3, 2022 15:45:12 GMT -5
Not quite right....but pretty good.
My panels are the 1.6 model.
The crossover is generally considered to be at 600hz. That is what'd I'd judge to be the -3db or maybe -6db point.......
Woofer? Low pass 12db /octave consists of a 16ga iron core inductor and some capacitors.....somewher below 600hz.(your 2nd order)
Tweeter? High Pass of 6db / octave of only capacitors. (plain 1st order) set somewhat just above 600hz.....
That arrangement pretty much 'sums flat' thru the passband.....
So? Woofer / tweeter are 90 degrees 'out'.....which is made up for by slight toe-in of final setup. This time aligns woof / tweet.......After all, 90degrees is only a few Milliseconds
Given your definition, than NO speaker is phase coherent. I've seen some where the voice coils are aligned which is said to produce a coherent launch....?? Magnepan with a single plane of diaphragm should do much the same.
Cap and coil crossovers are a nightmare when it comes to this discussion. DCM Time Window? Others?
ONLY way around that I know is Maybe an FIR filter which has no phase shift thru the passband....and would be a worthwhile experiment for the magnepan DIY guy....
Other models in the line use other crossovers. Some panels are 3-way, others are so-called 2 1/2 'way'.......And some even use a series crossover which removes the abilty of passive biamp.
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Post by Boomzilla on Oct 3, 2022 16:42:22 GMT -5
MANY speakers have been designed and sold that are FULLY phase-coherent and time-aligned. Among them:
Dahlquist DQ-10a
Thiel 1.5, 1.6, 1.7
Thiel 2.3, 2.4, 2.5
Thiel 3.5, 3.6, 3.7
Thiel 5, 5i
Thiel 6
Thiel 7
Vandersteen (multiple models)
+ many others
These speakers stagger their driver mountings to create a simultaneous wave launch, AND they use first-order crossovers (6dB / octave) with all drivers IN PHASE with each other. Such designs place greater demands on the drivers (all of which must reproduce frequencies beyond their normal bandpass).
Some designers claim that phase doesn't matter and that time alignment of drivers doesn't matter. But the greater the resolution that a system has, the more you find out that this MAY be wrong... Of course, sitting at a significant distance from the speakers blurs the sound sufficiently with room reflections that you might not notice phase coherence and time alignment. But to hear what your speakers are REALLY doing, listen to them in a near-field setting. In such a setting, you WILL notice that a phase-coherent (time-aligned) speaker will sound FAR more realistic than ANY speaker that lacks these design attributes.
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Post by leonski on Oct 3, 2022 17:01:05 GMT -5
yes....I've seen the DQ10 a long time ago.
Lining up voice coil can produce a 'stepped baffle' which is its own problem in need of a solution......
But looking down from the top....alll the voice coils are in a row.....
Good idea with 6db / in phase speakers. maggie does the same thing by putting one driver to the side of the other and using toe to basically adjust the distance
between drivers so the 'arrival' is simultaneous. for these purposes the phase shift between crossovers can be 'timed'......
That' is not a perfect technique, of course
I wonder how well a single driver / full range speaekr soes in this regard.??
I've seen some Thiel crossovers which were in the region of Square Feet.......Huge and many components.....
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Post by Boomzilla on Oct 3, 2022 18:05:27 GMT -5
I wonder how well a single driver / full range speaekr soes in this regard.?? I've seen some Thiel crossovers which were in the region of Square Feet.......Huge and many components..... By definition, a single driver speaker is almost always phase-coherent. There are some exceptions such as "bending driver" speakers whose cones deliberately flex... The Thiel crossovers, despite their many components (which are, for the most part, just notch filters) ARE first-order AND phase-coherent. |
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