The Most Useless Machine EVER!
Somebody has also made a LEGO version useless machine
Archive for September, 2011
Useless Machines
Friday, September 30th, 2011Common DC voltage levels
Thursday, September 29th, 2011DC voltage levels:
0.7V Nominal voltage drop on normal silicon diode or similar semiconductor junction
0.8V Voltages from 0V to 0.8V are considered to be logic 0 on TTL logic IC inputs
1.25V NiCd, NiMH battery cell nominal voltage
1.5V Carbon and alkaeline battery cell nominal voltage
1.6V The voltage you normally get from a fresh alkaeline battery cell
1.8V Quite commonly used very low voltage digital circuit operating voltage (many CPU cores)
2V Lead acid battery nominal cell voltage
2V Voltages from 2V to 5V are considered to be logic 1 in TTL logic IC inputs.
3V Lithium battery nominal voltage
3.3V LVTTL logic circuits operating voltage
3.6V Typical voltage used to power cell phones (either from NiMH or Li-Ion battery pack)
4.5V operating voltage for many small electronics gargets powered from three batteries
5V TTL logic circuits operating voltage
6V operating voltage for many small electronics gargets powered from four batteries
9V Commonly used battery voltage
10V Normal control voltage limit in 0-10V and 1-10V analogue control systems (light dimming and industrial use)
12V Car battery nominal voltage
13.8V the voltage you expect to get from car 12V power when car motor is running (charging battery)
24V Truck battery.
24V Automation systems most common nominal voltage used for logic signals and and current loop powering
24V common standard input voltages in Avionics and Defense applications
28V Maximum battery charging voltage for 24V battery system (for example batteries that power automation systems).
28V common standard input voltages in Avionics and Defense applications
36V Battery voltage used on some electric golf carts, electric scooters, electric bikes, high power cordless tools etc..
42.4V Voltages must be less than or equal to 42.4V peak/60V dc to meet safe limits and to be SELV.
42.4V Hazardous Voltage is a voltage exceeding 42.4V peak or 60V d.c., existing in a circuit which does not meet the requirements for either a Limited Current Circuit or a TNV Circuit.(IEC 60950)
48V Battery backed up -48V voltage is used on telecom systems for powering telephone exhanges and other telco equipment. The normal service voltage range for the -48 Vdc nominal supply at interface “A” shall be -40,5 Vdc to -57,0 Vdc according to ETSI EN 300 132-2
48V Some data centers use 48V DC to power servers (battery backup easy)
48V Phantom power feed for microphones in audio mixers most often uses +48V phantom power voltage
48V some automation systems use +48V power for equipment and I/O (electrical power distribution)
50V Work on energized circuits or apparatus below that voltage requires no “Hazard/Risk Evaluation.” NFPA 7OE
60V Voltages must be less than or equal to 42.4V peak/60V dc to meet safe limits and to be SELV.
60V Hazardous Voltage is a voltage exceeding 42.4V peak or 60V d.c., existing in a circuit which does not meet the requirements for either a Limited Current Circuit or a TNV Circuit.(IEC 60950)
72V standard input voltage in rail applications
75V Low Voltage Directive is effective for voltages in range 50 – 1000 volts a.c. or between 75 and 1500 volts d.c
110V Seen on electrical power distribution control automation as IO voltage and for operating actuators on high voltage power distribution stations.
110V standard input voltage in rail applications
120V Extra-low voltage high limit is 120 V ripple-free d.c.
125V Commonly used insulation resistance testing voltage used for low voltage wiring testing where 250V test voltage is too much.
160V The highest DC voltage covered by the telephone/telecom/ITE industry is 160V (ANSI T1.311)
169V The peak voltage on 120V AC mains power is around 169V, you get around this voltage if you rectify and filter 120V mains power
220V Seen on electrical power distribution control automation as IO voltage and for operating actuators on high voltage power distribution stations.
250V Commonly used insulation resistance testing voltage. Tests on SELV and PELV circuits are carried out at 250 V.
270V common standard input voltages in Avionics and Defense applications
324V The peak voltage on 230V AC mains power is around 324V, you get around this voltage if you rectify and filter 230V mains power
380V DC power voltage for DC feed used on some data centers. Emerge Alliance pushes using this 380V system.
500V Commonly used insulation resistance testing voltage. Insulation tests at normal mains wiring (230V) is commonly tested with 500V test voltage. Minimum insulation resistance expected on mains circuit is 0.5 Mohm. Also test between SELV and PELV circuits and the live conductors of other circuits must be made at 500 V.
575V DC power voltage for DC feed used on some data centers
600V Voltage used on
750V Voltage used to power trains in Helsinki subway (third rail powering)
1000V Commonly used insulation resistance testing voltage for circuits that operate above 500 V up to 1000 V.
1500V Low Voltage Directive is effective for voltages in range 50 – 1000 volts a.c. or between 75 and 1500 volts d.c
2500V Commonly used insulation resistance testing voltage
3250V Use 2300V rms or 3250V dc test voltage for dielectric-withstand test for double insulation
5000V Commonly used insulation resistance testing voltage when testing high voltage wiring
BBC plans to use 3D and ’super hi-vision’
Wednesday, September 28th, 2011BBC plans to use 3D and ’super hi-vision’ for London Olympics article tells that executive in charge of 2012 coverage has spoken about the proposed experiment: The BBC is considering plans to broadcast the 100 meters final of the London Olympics in 3D, as well as trying out a new super high-definition technology.
Super Hi-vision (Ultrahigh-Definition Wide-Screen System with 4000 Scanning Lines) is the technology developed by NHK Science & Technical Research Laboratories that delivers the images at considerable higher resolution than HDTV. The picture quality is picture quality is said to be 16 times better than HDTV.
It is claimed that this technology is so real that viewers feel as if they were actually at the site of the broadcast and find themselves attempting to touch what’s on the screen (by the way same type of promises was made in the introduction of HDTV if I remember rigt). The large, wide-screen video images with the resolution equivalent to that of printing strike viewers as a fresh surprise. The cutting-edge technology captures the attention of the international community.
Super Hi-Vision feed over IP page gives some details on the data rates on this new video system: Live feed made use of a codec developed by NHK for efficient transmission and broadcast of Ultra High Definition TV signals. The encoder compresses the video signal from approximately 24Gbps down to 180-600Mbps and the audio from 28Mbps to 7-28Mbps. Wikipedia Ultra High Definition Television has also some additional information on different higher resolution than HDTV video systems.
Google Native Client
Tuesday, September 27th, 2011One of the key features of the web is that it’s pretty safe to click on almost any link. Your browser can fetch code from some unknown server on the internet and run it.
In the browser you can use any language you want – as long as it’s JavaScript. JavaScript is an interpreted, dynamically-typed language, and it was specifically designed to protect netizens from malicious and buggy code. Nowadays you can also program with other languages and convert the result to JavaScript with suitable tools (Java, C/C++, etc..). With browser extensions some more languages are possible (Java, Flash actionscript etc..).
Native Client – a Google open source project more than three years in the making – is specifically designed to run native code securely inside web browsers. It tried to put web applications on “the same playing field” as local applications, providing the raw speed needed to compete with traditional software on 3D games, video editing, and more. Google Native Client: The web of the future – or the past? article gives some more details on this technology. Google’s idea is to create a system that tries to give languages like C and C++ – but eventually others as well – the same excellent level of portability and safety that JavaScript provides on the web today.
As it stands today, Native Client is a software “sandbox” meant to securely run native code inside a browser. Native Client can give you a tremendous improvement in performance compared to other options for running code in the browser. The rub is that Native Client isn’t the web – at least not yet. It will soon be an integral part of Google’s browser and its browser-based operating system.
Chrome will only accept Native Client applications distributed through the Chrome Web Store, and Google will only allow Native Client apps into the store if they’re available for both 32-bit x86 and 64-bit x86 (the ARM version of Native Client is not yet ready for prime time).
The problem for wide adoption is that Native Client hasn’t been integrated with other browsers. It hasn’t been standardized. Is this development direction good or bad for the web I am not sure.
Philips winning LED-based 60W replacement bulb
Monday, September 26th, 2011Philips wins $10M L Prize for LED-based 60W replacement bulb article tells that Philips wins $10M L Prize for LED-based 60W replacement bulb. The bulbs had to meet or exceed a set of requirements: greater than 900lm at 10W or less (efficacy of greater than 90W/lm) at a color-corrected temperature (CCT) of 2700-3000K and a color rendering index (CRI) of at least 90.
The winning Philips bulb uses a clever remote phosphor system to gain a spherical distribution of light. For more details on that read the Philips LED bulb tear-down article.
L Prize competition is planned to accelerate America’s shift from inefficient, dated lighting products to innovative, high-performance products. DOE’s first L Prize category launched in 2008 targets the 60-watt bulb because it is one of the most widely used types of light bulbs by consumers, representing roughly half of the domestic incandescent light bulb market (more than 425 million bulbs sold in USA every year).
Write only memory
Friday, September 23rd, 2011Write-only memory has been one of the best practical jokes on the electronics industry field.
Write-only memory (WOM) is the antithesis of read-only memory (ROM). By definition, a WOM is a memory device which can be written but never read. The WOM concept is most often used as a joke or a euphemism for a failed memory device.
An engineer at Signetics, frustrated by the long and useless sequence of approvals for data sheets (during which no actual checking occurred), once made up a spec for a “Write Only Memory” (a “WOM”) and sent it along with a batch of other data sheets to be approved. The WOM data sheet went through the approval chain, just fine, and wound up in Signetics’ new products catalog at 1970’s. Only after customers began asking for price and delivery. Signetics shortly printed up new “corrected” databooks, without any WOMs, and asked for the “erroneous” ones to be returned.
About 1974, Signetics bought a two-page, full-color spread in the April issue of ELECTRONICS Magazine, and published the WOM data sheet, as a (rather expensive) April Fool’s Joke. The data sheet is quite funny reading even today.
Cat 5 Cable Modeling
Thursday, September 22nd, 2011Category 5 (CAT5) cable is a multi-pair (usually 4 pair) cable that consists of twisted pair conductors, used mainly for data transmission. Basic CAT5 cable was designed for characteristics of up to 100 MHz. Newer CAT6 cable is designed form 250 MHz. Nowadays there are applications where those cables is used to carry higher frequencies.
Cat 5 Cable Modeling for DVI/HDMI links tells how to analyze the cable performance. The behaviour of each twisted pair is determined by the complex three-dimensional
electromagnetic field in the region within and surrounding the cable. For communications link performance verification we require a simplified representation of the cable that is computationally viable and can be included within the circuit verification environment. The model also needs to correctly represent important cable parameters such as delay, near and far end crosstalk and cable losses.
Cat 5 Cable Modeling for DVI/HDMI links article gives a simple C++ module was written and added to the CppSim behavioural modelling environment. The article also gives a Hspice ‘W’ model.
The combination of field solver and multi-conductor W model in Hspice can be used to simulate all the key signal degradation characteristics such as frequency dependent loss, delay, near and far end coupling and the effect of discontinuities for different UTP cable geometries.
Arduino Goes ARM
Tuesday, September 20th, 2011The whole world seems to be going in ARM’s direction. ARM has practically taken the mobile phone and tablet markets. The latest version of Windows 8 will also run on ARM processors, Raspberry Pi is a $25 ARM based machine etc..
Slashdot tells that now the open source Arduino platform has a new member — the ARM-based Arduino Due announced at the Maker Faire in New York.
The Due makes use of Atmel’s SAM3U ARM-based processor, which supports 32-bit Cortex-M3 ARM instructions. The SAM3U processor from ATMEL is running at 96MHz with 256Kb of Flash, 50Kb of Sram, 5 SPI buses, 2 I2C interfaces, 5 UARTS, 16 Analog Inputs at 12Bit resolution and much more. This is much more powerful than the current Uno or Mega.
Unfortunately the 3.3V operating voltage and the different I/O ports are going to create some compatibility problems. Arduino boards have been traditionally with 5V I/O, although 3.3V seems to become more and more popular. Adafruit has a tutorial on converting Arduino Unos over to 3.3v, from 5v. It’s becoming popular. The usefulness of 5V is diminishing.
I don’t see this new Due board as a direct replacement for the 8-bit ATmega based Arduinos, but more as a step up up for those looking for more processing power. A port to ARM for the user friendly Arduino toolkit had been long talked, but this is an official ARM-Arduino board with official support in the arduino toolchain.
To connect this board to Internet you will need to have some additional hardware, because Due does not have any built-in network interface. For Arduino use there has been long time Ethernet Shields (different models) and now also official Arduino Wifi Shield.
Noise Reduction Techniques
Monday, September 19th, 2011Noise Reduction Techniques in Electronic Systems book except has some interesting reading on ground loops and inductive noise reduction. This is old but still very valid material from Henry Ott, the EMC, noise, and signal integrity guru.
Read also Ground- A Path For Current Flow article which says: Consider ground as a low impedance path for current to return to the source, instead of as an equipotential, emphasizes the importance of current flows thought a finite, but hopefully small impedance any two ground points that are physically separated will be at different potentials.
Video coat
Friday, September 16th, 2011Friday special: Groovy Video Coat video I found on Internet:
More details on electronics can be found on Groovy Video Coat pictures and this Video Coat Prototype video:
