Err, we're talking radio mics here. And pro ones are in a different league to the low end stuff. They have to be rugged - and possible to fix if damaged.
That's a stupid comparison - you'd have to take all those needed with you. Plus the fact that 'space' has easy and constant access to a source of power - the sun. Unheard of in the UK. ;-)
They use PP3s there? Or AAs? AAAs?
Cost almost certainly doesn't matter there.
Any battery used in that will be a backup.
Their requirements are likely different. With radio mics you need a cost/performance/reliability compromise.
I can give a reason. Very high capacity (and cost) primary cells might be ok where you can log the usage. Unfortunately in the film etc world this isn't always possible - one person might be looking after dozens of the things. So fitting brand new ones with a reasonable life is simply more convenient - you change them all at natural break times. That might be once a day - or twice. With some, three times. Most give a life of at least 5 hours.
Thanks for showing you don't have any understanding of this industry.
Think I met you once in the form of a large middle aged lady. I was working on a live TV current affairs program. Went to clip a mic on her and she said 'I don't need that, I have a perfectly good voice'
It's as well to understand the problems in an individual industry before trying to apply fixes from another. TV is full of kids just out of college trying to do just that - and failing miserably. I've seen hundreds come and go...
One of the most important things with some RMs is size - if they have to be concealed on the body. Better batteries allow smaller units. But good RMs are extremely expensive and none will junk good ones just for this.
--
*Change is inevitable, except from a vending machine.
Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
One thing they don't use is Lithium. The equipment we supplied had to be modified to eliminate the 2K*8 lithium battery backed SRAM. The equipment was for use in the crew quarters of the Space Station. We used some 'CapStore' SRAM that is apparently no longer in production.
Generally, they use specially designed Ni-cads in space vehicles. That is where the myth of Ni-cad 'memory' came from.
--
http://improve-usenet.org/index.html
aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.
If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm
There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you\'re crazy.
"Michael A. Terrell" wrote in news:dMmdndGkyPURjdLUnZ2dnUVZ snipped-for-privacy@earthlink.com:
Ok. Explosion risk? (Or perhaps noxious and corrosive fumes in enclosed small volumes, most likely, I guess, if they rupture.) I remember such batteries appearing on surplus output long before most people even heard of lithium batteries, so I guess they were being rejected from somewhere. They were fine though, for me. Still got some even now. Bit of electrode plating requiring a very short burst discharge to wake them, and off they go like the Energizer bunny, but slowly, not designed for high peak loads..
The reason for last night's rant is that I see so much dismissal of other technologies, and when people talk of what amounts to a claim for mission critical performance, they should continue to explore other similar requirements, see what they do. It's changing all the time. Lithium based battery tech is developing so fast that it's not sensible to dismiss it and cling to something that is a (significant, granted) step up from the dry cell. When I look at details on current lithium and Li-ion cells, I see something that is ready now. Some basic calulations show that their cost per unit time usable makes them similar to alkaline, with a quarter waste by volume, maybe better, and a saving on changing times by same factor (not to mention disruption of people who need to wear or carry those things with as little disturbance as possible in the course of a day). Can't ignore stuff like that. People staying with what they know while talking up the value of their own jobs seem in as poor a position to judge new developments as I am to judge their jobs... The only way they'll change that is if they explore more than they dismiss, and I don't see that happening here despite all the facts and figures trotted out.
Damn, there went my resolve not to post in this, but talking to someone who makes sense to me more often than not is harder to resist than those who would retort mainly because I ranted at them. And it's a very quiet night..
A thought I have about RF mics... what about the little 10 KHz induction chargers used in toothbrushes? If they could be stacked in a case that had a single source driving a coil in each cradle, the effort to maintain charges need be no worse than that of collecting devices and putting them in the case, a task no doubt already needed. If it is economic for cheap electric toothbrushes it has to be viable for expensive RF microphones.
Nasa stated that they wanted zero chance of the lithium getting into the living space, or the on board electronics.
Quite often they get packed and trucked to the next job with no time to charge them. How are you going to power a hundred or more chargers in a moving vehicle, and monitor the charges? One TV station I worked at made the mistake of buying a pair of rechargeable wireless microphones. They were great, for about two months. Then the custom battery packs had to be replaced at over $200 each. During that time they would have used less than $50 worth of Alkaline cells. The replacements weren't rechargeable.
--
http://improve-usenet.org/index.html
aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.
If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm
There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you\'re crazy.
"Michael A. Terrell" wrote in news:QtKdndtOo43du9LUnZ2dnUVZ snipped-for-privacy@earthlink.com:
Case/charger fed from vehicle supply? Or a larger battery packed with them? Charge monitor for Li-ion is simple, one in each unit would switch it off when it had enough. If it works for toothbrushes it can work for mics.
2 months sucks, but I know my cheap Chinese Li-ions have coped way better than that on a cheap Chinese charger, so I don't doubt that a bad case in the past isn't a way to judge a future, when even a basic standard current example is good. I think the question is whether the organisation needed to make the change is worth the time saved. Considering the premium some people here put on their time, their jobs, their reputation, it surely is. Alkaline probably makes awesome backup so I'm not suggesting throw them out, but relying on them doesn't make sense to me. Scaling up the small use of Li-ion (which is definitely better for constant modest drain in a small flashlight) to a repeatable application for a hundred similar items doesn't multiply a problem, it divides it.
Lostgallifreyan wrote in news:Xns9B7C3A3E684A8zoodlewurdle@216.196.109.145:
Small extra bonus to this idea: discharge monitor. Nothing fancy, just enough to let the user know when it's perhaps 90% down. That way you get way longer than alkaline discharge time, and plenty of warning ahead of time instead of a sudden stop. As Li-ion batteries don't like deep discharge, such a monitor will be part of the battery control circuit. It's easy to think of this as part of the cost of the battery, but that's not correct. It's part of the cost of the device, and a small one too.
How are you going to do that in the back of a tractor trailer that's loaded with equipment? You aren't allowed to modify the vehicles, and in most cases, you never see the same rig & driver twice in a row.
You should work a big show sometime with a crew of dozens of people where you only have a couple hours to unload multiple tractor trailers of equipment, set it up and test it in time for the event. Jakdert does large convention shows, not small one man jobs.
What would you do if you got a batch of defective Li-on batteries that started fires? One could put you out of business. A lot of laptop computers have ben destroy by defective cells, and some idiot tossed a burning laptop into the back of the crew cab on his pickup truck. The fire not only destroyed the laptop, it burnt the truck, and injured his young daughter who was strapped in, in the passenger seat.
--
http://improve-usenet.org/index.html
aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.
If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm
There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you\'re crazy.
Then you interrupt a performance to replace the weak battery?
--
http://improve-usenet.org/index.html
aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.
If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm
There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you\'re crazy.
"Michael A. Terrell" wrote in news:QLydnTOAJdC97tLUnZ2dnUVZ snipped-for-privacy@earthlink.com:
You're underestimating the life of a charge. It won't end before a performance, even if that performance lasts all day, unless you set it up without it being charged during some time earlier. There'd be more chance of an alkaline dying on that time scale. Perhaps 4 times.
"Michael A. Terrell" wrote in news:QLydnTCAJdBf79LUnZ2dnUVZ snipped-for-privacy@earthlink.com:
By loading it all in the same box.
Well, the idea I have is this. It might have problems, but it seems doable to me. Lead-acid is heavy, but not that big a part of a large trailerful, and fairly small, and safe (they can travel in the UK with no special handling, in couriers vans and such). So when the box with that and the case of mics is unloaded, the battery is plugged in, the mics moved to where needed, all charged. At the end, the power is unplugged, the mics cased, lid closed, box loaded.
Is this really so unfeasible? Isn't it worth it to save the change time for loads of batteries with smaller charge times? The case/charger design and the mics are a larger investment but on that scale it might pay back fast.
That's a bad one, but I think running Li-ion in a hot laptop is likely different to the low-drain conditions in a mic. I've heard of laptop fires, but not burning mics. Or flashlights.
I had an old wireless mic from a church that was built with a ni-cad rechargable battery pack. It shorted out & caught fire while being used. It burnt a hole in the user's shirt and gave him some bad burns.
--
http://improve-usenet.org/index.html
aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.
If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm
There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you\'re crazy.
"Michael A. Terrell" wrote in news:f-idnedTT_OZEtLUnZ2dnUVZ snipped-for-privacy@earthlink.com:
Ok. But I think they will improve reliability and safety margins. Lithium batery technology is (as far as I can tell) the single most developed tech currently. So how long will it be before it's viable to trust as alkalies are? Rhetorical question. I don't think it will be long at all. And, you said NiCd. :) I think those are worse than Li-ion for risk. Also, I think an RF mic with a charge/discharge monitor for Li-ion might also have a cheap current limit resistance or other protection fitted in immediate series contact with the battery.
There is one detail I am not sure of; that's whether the cost would significantly rise if the battery compartment had a hatch. WOuld be best if it had, so that Li-ion batteries can be changed at need, and when really needed, an alkaline fitted in place. If the same device allows both, uptake might be better.
I have never met anyone who wants that blasted sidebar.
--
http://www.petersparrots.com http://www.insanevideoclips.com
http://www.petersphotos.com
Cindy once remarked to her dentist that she didn\'t know what would be worse -
having a baby, or having a tooth pulled.
The Dentist replied, "Well make up your mind, Cindy - because I need to know
which way to position the chair."
What do you think set the parrots on fire in the first place? It wasn't his all lead & plastic Chinese smoke alarms.
I love the smell of smoked parrot, in the early dawn of the morning!
--
http://improve-usenet.org/index.html
aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.
If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm
There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you\'re crazy.
A few years back I bought a stack of £1.99 smoke alarms from a supposedly reputable chemists chain (the non-special offer price was quite a bit higher). These alarms became insensitive to smoke after only a couple of months - pressing the test button worked but holding a cigarette to the sensor no longer set it off. The landlord subsequently installed commercial duty rechargeable smoke alarms.
The £1.99 alarms turned out to be good value for the batteries they contained, a handy source of battery clips and I may eventually find a use for the very loud piezo sounders.
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.