Breaking News
<<   <   Page 2 / 2
User Rank
Author
re: GravityLight – What a GREAT idea!
1/7/2013 8:26:47 AM
NO RATINGS
Simple and Genious! :)

User Rank
Author
re: GravityLight – What a GREAT idea!
1/6/2013 11:02:00 PM
NO RATINGS
Well, based on the calculator at http://convert-to.com/159/energy-units.html 100 ft-lb = 135.58 J, and by my calculations a 3V LED powered by a 100% efficient generator that draws 20 mA will stay lit for 37.7 minutes. I would estimate for the 3-LED system shown with a 50% efficient power conversion system would give about 6 minutes of light per 5 foot 100 pound lift. That is some big bag to hold 100 lb. The Gravity Light web page talks about a 20-pound weight, and says 18 to 30 minutes of light output per lift. I agree something seems a little off...

User Rank
Author
re: GravityLight – What a GREAT idea!
1/5/2013 2:30:25 AM
NO RATINGS
Has someone done the math on this? a 20 pound bag lifted 5 feet has 100 foot-pounds of potential energy. At an efficiency of 20%, how long will a 20ma LED provide light?

User Rank
Author
re: GravityLight – What a GREAT idea!
1/4/2013 8:29:28 PM
NO RATINGS
There was an article on this at The Register a few weeks ago: http://www.theregister.co.uk/2012/12/12/deciwatt_gravity_light/ One advantage of this device is that, other than the LEDs (I think), it is relatively low tech and could be mostly manufactured or at least assembled locally (an economic advantage, not just a hand-out but partly a hand-up) and quite possibly maintained/repaired locally. I still think that the child-powered (merry-go-round) water well pumps are a little more clever in terms of exploiting an abundant energy source and providing fun.

<<   <   Page 2 / 2

Drones are, in essence, flying autonomous vehicles. Pros & cons surrounding drones today might well foreshadow the debate over the development of self-driving cars. In the context of a strongly regulated aviation industry, "self-flying" drones pose a fresh challenge. How safe is it to fly drones in different environments? Should drones be required for visual line of sight, as are piloted airplanes? Is the technology advancing faster than we can answer the questions it poses? Panelists: Chad Sweet, Director of Engineering, Qualcomm; Yannick Levy, VP Corporate Business Development, Parrot; Jim Williams, ex-FAA drone chief; Michael Drobac, Exec. Director, Small UAV Coalition; Moderator: Junko Yoshida, Chief Int'l Correspondent, EE Times
July 16, 1pm EDT Thursday
Flash Poll

#### Datasheets.com Parts Search

##### 185 million searchable parts (please enter a part number or hit search to begin)
Special Video Section
LED lighting is an important feature in today’s and future ...
5:27
Active balancing of series connected battery stacks exists ...
9:29
After a four-year absence, Infineon returns to Mobile World ...
6:23
A laptop’s 65-watt adapter can be made 6 times smaller and ...
2:01
An industry network should have device and data security at ...
0:50
The LTC2975 is a four-channel PMBus Power System Manager ...
5:06
In this video, a new high speed CMOS output comparator ...
6:11
The LT8640 is a 42V, 5A synchronous step-down regulator ...
5:52
The LTC2000 high-speed DAC has low noise and excellent ...
5:14
How do you protect the load and ensure output continues to ...
6:54
General-purpose DACs have applications in instrumentation, ...
7:34
Linear Technology demonstrates its latest measurement ...
10:29
Demos from Maxim Integrated at Electronica 2014 show ...
4:17
Bosch CEO Stefan Finkbeiner shows off latest combo and ...
5:59
STMicroelectronics demoed this simple gesture control ...
2:15
Keysight shows you what signals lurk in real-time at 510MHz ...
4:17
TE Connectivity's clear-plastic, full-size model car shows ...
3:42
Why culture makes Linear Tech a winner.
6:08
Recently formed Architects of Modern Power consortium ...
6:39
Specially modified Corvette C7 Stingray responds to ex Indy ...
8:52