With a DVD drive he can make multiple copies of his data, then mail them separately from different origins for redundancy. Much cheaper to do this with 25 cent DVD's than with $30 flash drives. Besides, if he mails home a flash drive and it happens to be irradiated by the USPS, it'll be destroyed (or at least lose data). Can't find any hard information on what mail is irradiated (just Washington DC and NYC?) and whether or not DVD's are affected adversely. Do any other countries irradiate or do strong X-Ray scanning of mail?
Before you say that he should be able to fit thousands of pictures into one 4GB (8GB, 16GB, etc) card so he doesn't need more than one, maybe he has a DSLR and wants to save pictures in RAW format to preserve quality. He may only be able to fit a few hundred pics per card and may fill up more than one card per day.
Plus he probably wants to do some editing and annotating in the field so he can better organize the pics back home, if he's going to lug around a laptop anyway, he may as well include a DVD drive for burning pics cheaply and easily.
It's not so much the AC->DC conversion that's inefficient and making your wall warts warm, it's the cheap linear regulators.
Many modern wall warts use much more efficient switching power supplies - and these would not be any more efficient if you supplied them with DC from the wall instead of 120VAC. The transformer itself is probably the most efficient component in any power supply - it's the filtering and DC regulation that tend to waste power.
Running low voltage DC isn't really going to help you out much since different electronic devices need different voltages due to technical reasons (type of semiconductors used, LCD/VFD/LED displays, peripherals, etc). If you really wanted to eliminate voltage conversions at the wall, you'd have to provide a large range of voltages...for example, 3.0, 4.5, 6.0, 7.5, 9.0, 12.0, 19.5, and 24V would be a good start, but there would still be devices that aren't included.
If you want manufacturers to standardize on one voltage, then that means that every device is going to have to have a built-in dc-dc converter to convert from the standard voltage to the one it wants (or use inefficient linear regulators to step down voltage when the standard voltage is higher than it wants).
Running low voltage DC to power everything means running larger wires through the walls since a 70 watt laptop that needs about half an amp of current at 120VAC to run will need over 5 amps at 12VDC.
So, running DC through the walls isn't going to help efficiency, and may even lower efficiency due to increased line loss because of higher currents at low voltage.
It's clear that you're just trolling, but really - is that the only way you could find to tear apart my post? Seems silly to try to redirect the discussion by accusing me of lying to you when all I did was clearly point out where my originally quoted numbers came from.
Could you at least make a token effort to respond to the points I made?
You may be a troll, but you're not a very good one.
I already did show you which Tivo I was referring to. Or at least told you where to look -- I said "I think you missed the parent thread" so if you go look at the parent to my thread it says:
Great! Where can I get a MythTV box preconfigured for $100? [compusa.com] I will patiently await your link. Thanks ahead of time!
If you read my first post again, I even broke down the math to make it clear that I was using $100 as the baseline price for the Tivo, then added the service fees to that to come up with a total. Not sure how I could have made it more clear other than reposting the parent, but that shouldn't be neccesary since slashdot already groups threads together. Try using the Nested view when reading articles and threads become more clear.
And while I appreciate your link to a USED unit (which costs almost as much as the brand new $100 unit + 2 years of service), I assumed it was clear that I was talking about new hardware. If you want to open the "scrounge up used hardware" can of worms, then we'll get a dozen postings that claim "I built a MythTV box out of hardware I found in my basement for free!!"
Oh, and I don't own a Tivo, I own a ReplayTV (from back when they still had automatic commercial skip) and diligently pay my $10/mo. After it finally dies, I'll look into building a MythTV box.
TiVo Basic service is a complimentary version of the TiVo service available only on DVD integrated models from Toshiba and Pioneer. TiVo Basic service is not available on standalone TiVo DVRs.
I couldn't find any for sale after a quick search, I think list price on these units was between $450 and $1200.
Besides, Tivo basic has some annoying limitations -- only 3 days of program guide, no title search, no "season pass" where you can tell it to play all instances or your program regardless of time or channel.
To be fair, your Tivo costs $100 + $179 = $279 if you keep it for a year. If you keep it for 2 years, then it's at least $100 + $299 = $399. Prices are higher if you pay monthly.
I doubt you can build an equivalent MythTV box for $279, but perhaps for $399? A quick google search couldn't find any for sale -- does anyone sell preconfigured MythTV boxes?
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With a DVD drive he can make multiple copies of his data, then mail them separately from different origins for redundancy. Much cheaper to do this with 25 cent DVD's than with $30 flash drives. Besides, if he mails home a flash drive and it happens to be irradiated by the USPS, it'll be destroyed (or at least lose data). Can't find any hard information on what mail is irradiated (just Washington DC and NYC?) and whether or not DVD's are affected adversely. Do any other countries irradiate or do strong X-Ray scanning of mail?
Before you say that he should be able to fit thousands of pictures into one 4GB (8GB, 16GB, etc) card so he doesn't need more than one, maybe he has a DSLR and wants to save pictures in RAW format to preserve quality. He may only be able to fit a few hundred pics per card and may fill up more than one card per day.
Plus he probably wants to do some editing and annotating in the field so he can better organize the pics back home, if he's going to lug around a laptop anyway, he may as well include a DVD drive for burning pics cheaply and easily.
It's not so much the AC->DC conversion that's inefficient and making your wall warts warm, it's the cheap linear regulators.
Many modern wall warts use much more efficient switching power supplies - and these would not be any more efficient if you supplied them with DC from the wall instead of 120VAC. The transformer itself is probably the most efficient component in any power supply - it's the filtering and DC regulation that tend to waste power.
Running low voltage DC isn't really going to help you out much since different electronic devices need different voltages due to technical reasons (type of semiconductors used, LCD/VFD/LED displays, peripherals, etc). If you really wanted to eliminate voltage conversions at the wall, you'd have to provide a large range of voltages...for example, 3.0, 4.5, 6.0, 7.5, 9.0, 12.0, 19.5, and 24V would be a good start, but there would still be devices that aren't included.
If you want manufacturers to standardize on one voltage, then that means that every device is going to have to have a built-in dc-dc converter to convert from the standard voltage to the one it wants (or use inefficient linear regulators to step down voltage when the standard voltage is higher than it wants).
Running low voltage DC to power everything means running larger wires through the walls since a 70 watt laptop that needs about half an amp of current at 120VAC to run will need over 5 amps at 12VDC.
So, running DC through the walls isn't going to help efficiency, and may even lower efficiency due to increased line loss because of higher currents at low voltage.
It's clear that you're just trolling, but really - is that the only way you could find to tear apart my post? Seems silly to try to redirect the discussion by accusing me of lying to you when all I did was clearly point out where my originally quoted numbers came from.
Could you at least make a token effort to respond to the points I made?
You may be a troll, but you're not a very good one.
If you read my first post again, I even broke down the math to make it clear that I was using $100 as the baseline price for the Tivo, then added the service fees to that to come up with a total. Not sure how I could have made it more clear other than reposting the parent, but that shouldn't be neccesary since slashdot already groups threads together. Try using the Nested view when reading articles and threads become more clear.
And while I appreciate your link to a USED unit (which costs almost as much as the brand new $100 unit + 2 years of service), I assumed it was clear that I was talking about new hardware. If you want to open the "scrounge up used hardware" can of worms, then we'll get a dozen postings that claim "I built a MythTV box out of hardware I found in my basement for free!!"
Oh, and I don't own a Tivo, I own a ReplayTV (from back when they still had automatic commercial skip) and diligently pay my $10/mo. After it finally dies, I'll look into building a MythTV box.
http://customersupport.tivo.com/LaunchContent.aspx ?CID=EFB60828-EE03-4971-958B-E8EA9FDFC592
TiVo Basic service is a complimentary version of the TiVo service available only on DVD integrated models from Toshiba and Pioneer. TiVo Basic service is not available on standalone TiVo DVRs.I couldn't find any for sale after a quick search, I think list price on these units was between $450 and $1200.
Besides, Tivo basic has some annoying limitations -- only 3 days of program guide, no title search, no "season pass" where you can tell it to play all instances or your program regardless of time or channel.
Subscription rates are here: http://dynamic.tivo.com/2.0.plans.step.2.asp?box=s eries280hrDTDVR
I doubt you can build an equivalent MythTV box for $279, but perhaps for $399? A quick google search couldn't find any for sale -- does anyone sell preconfigured MythTV boxes?