Please create an account to participate in the Slashdot moderation system

 


Forgot your password?
Close
typodupeerror
×

Comment Re:Should have stayed old school (Score 2) 174

by Eric Smith (#58603558) Attached to: LED Light Can Damage Eyes, Health Authority Warns

LEDs most certainly can be "partially on", by regulating the current through them rather than operating at a fixed current (and thus fixed voltage). There are ICs that do that, e.g. the On Semiconductor CAT4016, though that is used for indicator LEDs rather than high-power illumination.

LEDs don't even have a specific "fully on" current. They are specified by their manufacturers with a maximum continuous current, but that isn't "fully on". The specifications also give a maximum pulsed current at some particular duty cycle, but that isn't really "fully on" either, because the maximum achievable current may be higher with a lower duty cycle. It's not clear that "fully on" actually has any specific meaning for an LED.

It's less expensive and more efficient to pulse-width modulate LEDs than to adjust the current, so pulse width modulation is definitely the most common way of varying LED intensity.

Comment Google announces new Micro USB-C connector (Score 1) 127

by Eric Smith (#57227866) Attached to: Google's $50 Titan Security Keys Are Now Available in the US

That's the most impressive part of the announcement, if you ask me. Their store page says that they have a "USB-C to USB-A adapter", which is nothing special, but also a "Micro USB-C to USB-A connecting cable".

I'm eager to hear when this new "Micro USB-C" connector will start appearing on Android phones and tablets.

Comment Don't blame the FCC (Score 1) 147

by Eric Smith (#53388461) Attached to: 'DroneGun' Can Take Down Aircraft From Over 1.2 Miles Away

If you think radio jamming should be legal, your issue isn't with the FCC, it's with US law, specifically 47 U.S.C. 333. Complain to Congress.

Despite that these and other jammers would have some beneficial uses, in my opinion it's a very good thing that radio jamming is illegal (with some exceptions for law enforcement and national security). Legalizing radio jamming in any form would cause far more problems than it would solve.

Comment Not all Li batteries are prone to thermal runaway (Score 1) 99

by Eric Smith (#53089881) Attached to: More Lithium Battery Product Recalls Predicted

Lithium iron phosphate (LiFePO4) batteries are considerably more stable than lithium polymer and are not prone to thermal runaway.

They have somewhat lower energy density than lithium polymer, which is probably why they're not very common for phones, tablets, and laptops. They were used in the OLPC.

They are also somewhat common in RC cars and planes, in part due to their voltage (3.2V, so four series cells make 12.8V), and in part due to their higher possible discharge current.

Submission + - Visual ARM1 - Celebrating ARM's 25th Anniversary (visual6502.org)

Submitted by trebonian
trebonian writes: Today is the 25th anniversary of ARM Ltd., UK. To celebrate and honor their amazing work, we present the Visual ARM1, created in collaboration with some of ARM's founding engineers.

Designed by Sophie Wilson and Steve Furber before there was an ARM Ltd., the Acorn RISC Machine was the first of a line of processors that power our cell phones and tablets today. Unlike our projects based on microscope images, the Visual ARM was created from a resurrected .cif chip layout file, used under our license agreement with ARM. We also photographed one of the few ARM1 chips at very high resolution, and our photograph is featured at the Centre for Computing History in Cambridge.

Credit goes to ARM founding engineers John Biggs for inspiring the project, discovering the tape, and recovering a usable .cif file, Lee Smith for spotting the variable record format used to encode the file (an artifact of the VMS on Acorn's VAX that at first appeared to be widespread corruption of the file), to Cambridge University Computing Services for reading the Exabyte tape, and to ARM founder Dave Howard for help unraveling the VLSI CIF dialect. Our chip simulation and visualization was developed by Barry Silverman, Brian Silverman, Ed Spittles, and Greg James.
Cellphones

Ask Slashdot: Best Data Provider When Traveling In the US? 142

Posted by timothy from the ok-what's-the-best-answer-in-august-2015 dept.
An anonymous reader writes: I am visiting USA 3-4 times a year and I need a data service. I also need to keep my cell phone number, so swapping the SIM card in my phone is not an option. I have bought those 19.95$ phones in Best-Buy to get a local number, but those were voice only. So I have been thinking about getting a MiFi hotspot.

I have been looking at pre-paid plans from Verizon(only 700 LTE band for their pre-paid hotspot), AT&T, T-Mobile etc. perhaps to put in a MiFi hotspot or buy a hotspot from a provider, but have no idea which one to use, their reputation, real life coverage etc. It is clear that all data plans in the USA are really expensive, I get 100GB monthly traffic with my Scandinavian provider for the same price as 6-8 GB monthly in the US, which I guess could be a problem with our Apple phones as they do not recognize a metered WiFi hotspot. But that is another issue. I travel all over but most of the time outside the big cities -- and my experience from roaming with my own phone and the cheap local phone so far tells me that coverage fluctuates wildly depending on the operator.
Oracle

Oracle: Google Has "Destroyed" the Market For Java 457

Posted by samzenpus from the bad-name dept.
itwbennett writes: Oracle made a request late last month to broaden its case against Android. Now, claiming that 'Android has now irreversibly destroyed Java's fundamental value proposition as a potential mobile device operating system,' Oracle on Wednesday filed a supplemental complaint in San Francisco district court that encompasses the six Android versions that have come out since Oracle originally filed its case back in 2010: Gingerbread, Honeycomb, Ice Cream Sandwich, Jelly Bean, Kit Kat and Lollipop.
Biotech

New Letters Added To the Genetic Alphabet 74

Posted by timothy from the q-and-z-and-x dept.
An anonymous reader writes with this excerpt from Quanta Magazine: [A]fter decades of work, [organic chemist Steven] Benner's team has synthesized artificially enhanced DNA that functions much like ordinary DNA, if not better. In two papers published in the Journal of the American Chemical Society last month, the researchers have shown that two synthetic nucleotides called P and Z fit seamlessly into DNA's helical structure, maintaining the natural shape of DNA. Moreover, DNA sequences incorporating these letters can evolve just like traditional DNA, a first for an expanded genetic alphabet. In fact, the article continues, these new nucleotides can actually outperform their natural counterparts: "When challenged to evolve a segment that selectively binds to cancer cells, DNA sequences using P and Z did better than those without."
Democrats

Obama Asks Congress To Renew 'Patriot Act' Snooping 389

Posted by Soulskill from the it-makes-you-safer-because-reasons dept.
mi writes: President Obama has asked the Senate to renew key Patriot Act provisions before their expiration on May 31. This includes surveillance powers that let the government collect Americans' phone records. Obama said, "It's necessary to keep the American people safe and secure." The call came despite recent revelations that the FBI is unable to name a single terror case in which the snooping provisions were of much help. "Obama noted that the controversial bulk phone collections program, which was exposed by National Security Agency contractor Edward Snowden, is reformed in the House bill, which does away with it over six months and instead gives phone companies the responsibility of maintaining phone records that the government can search." Obama criticized the Senate for not acting on that legislation, saying they have necessitated a renewal of the Patriot Act provisions.
Power

First Nuclear Power Plant Planned In Jordan 148

Posted by samzenpus from the power-up dept.
jones_supa writes Jordan has signed an agreement with Russia's state-owned nuclear power giant Rosatom, that sets the legal basis for building the kingdom's first nuclear power plant with a total capacity of 2,000 MW. The agreement is worth $10 billion and it envisages the construction of a two-unit power plant at Amra in the north of the kingdom by 2022. The deal provides for a feasibility study, site evaluation process and an environmental impact assessment. Currently Jordan imports nearly 98% of its energy from oil products and crude and is struggling to meet electricity demand, which is growing by more than 7% annually due to a rising population and industrial expansion. The kingdom hopes that eventually nuclear power could provide almost 40% of its total electricity generating capacity.
Government

To Avoid NSA Interception, Cisco Will Ship To Decoy Addresses 296

Posted by timothy from the name-is-smith-john-smith dept.
An anonymous reader writes with this news snipped from The Register: Cisco will ship boxes to vacant addresses in a bid to foil the NSA, security chief John Stewart says. The dead drop shipments help to foil a Snowden-revealed operation whereby the NSA would intercept networking kit and install backdoors before boxen reached customers. The interception campaign was revealed last May. Speaking at a Cisco Live press panel in Melbourne today, Stewart says the Borg will ship to fake identities for its most sensitive customers, in the hope that the NSA's interceptions are targeted. 'We ship [boxes] to an address that has nothing to do with the customer, and then you have no idea who, ultimately, it is going to,' Stewart says.
Music

$7.4 Million Blurred Lines Verdict Likely To Alter Music Business 386

Posted by samzenpus from the my-notes-I-take-them dept.
HughPickens.com writes The Washington Post reports that the $7.4 million verdict that Pharrell Williams and Robin Thicke copied Marvin Gaye's music to create their hit song "Blurred Lines" could ripple across the music industry, potentially changing how artists work and opening the door to new copyright claims. Howard King, lead attorney for Thicke and Williams, said in closing arguments that a verdict for the Gaye family would have a chilling effect on musicians trying to evoke an era or create an homage to the sound of earlier artists. Williams contended during the trial that he was only trying to mimic the "feel" of Gaye's late 1970s music but insisted he did not use elements of his idol's work. "Today's successful verdict, with the odds more than stacked against the Marvin Gaye estate, could redefine what copyright infringement means for recording artists," says Glen Rothstein, an intellectual property attorney. King says record labels are going to become more reluctant to release music that's similar to other works — an assertion disputed by Richard Busch, the lead attorney for the Gaye family. "While Mr. Williams' lawyer suggested in his closing argument that the world would come to an end, and music would cease to exist if they were found liable, I still see the sun shining," says Busch. "The music industry will go on."

Music copyright trials are rare, but allegations that a song copies another artist's work are common. Singers Sam Smith and Tom Petty recently reached an agreement that conferred songwriting credit to Petty on Smith's song, "Stay With Me," which resembled Petty's hit "I Won't Back Down." Other music copyright cases include Former Beatle George Harrison's 1970 solo song "My Sweet Lord" which had a melody heavy with echoes of "He's So Fine," the 1962 hit from The Chiffons. The copyright owner sued Harrison. A judge said that while the tunes were nearly identical, Harrison was guilty only of "subconscious plagiarism." Harrison would eventually pay out $587,000. Probably the most bizarre case of musical infringement was when John Fogerty was accused of stealing from John Fogerty. The Creedence Clearwater Revival frontman was sued for his 1985 solo song "The Old Man Down the Road" because his former label thought it sounded too much like the 1970 Fogerty-penned "Run Through the Jungle," a song it owned the rights to.

Submission + - FCC votes along party lines to regulate entire Internet

Submitted by jbdigriz
jbdigriz writes: In a stunning power grab, the FCC has extended Title II, not just to the loosely and flexibly defined "broadband" market, but to the Internet as a whole, wired and wireless, including even interconnects, making ISPs common carriers of telecom services, with the possible exception of dial-up providers (dunno, haven't seen the order yet). The commission voted also to override state law in NC and TN to remove restrictions on community broadband. Ars Technica has more info here. Lawyers, start filing. I'm sure the upshot will not be enshrinement of incumbents, of course. Or "openness" as defined by Fairness Committees of "Stake Holders." Right, suckers.

Slashdot Top Deals

Congratulations! You are the one-millionth user to log into our system. If there's anything special we can do for you, anything at all, don't hesitate to ask!

Close