Thursday, December 16, 2010

Ozone Generator Characteristics

Ozone gas is now-a-days used for treatment of drinking water, disinfection, and air-purification. What one re- quires is a small and handy unit to be plugged into mains to get ozonated air at suitable pressure flowing out from a tube It can then be let into environment or bubbled through water or any other polluted liquid. But the gadget must be completely safe to work with.

Ozone generators invariably make use of a discharge tube to which a high electric field is applied so as to break down the oxygen present in the air. This phenomenon occurs at or near a field strength of 25 kV/cm, and the resulting discharge that takes place is known as corona. The corona has a light bluish glow. It is in this corona field that oxygen becomes ozone (O3).

Ozone has tendency to revert back to its original form in about 10-20 minutes, in the atmosphere. Therefore, it is necessary in any ozone application to generate ozone as and when requied for use since it cannot be kept stored the way chlorine is stored (in cylinders). Chlorine is used in our cities to disinfect drinking water supply. It is highly carcinogenic because when it comes into contact with remnants of pesticides in our foodstuff (vegetables), it generathalomethanes, which are carcinogenic. That is why, ozone is used today in preference to chlorine.  Complete disinfection of water, in any impure form, is realised with an ozone content of 4 mg/litre.

Sunday, December 12, 2010

Advantages Of ZigBee

Though development of Zibee standards is still under progress, there are lot many applications for ZigBee due to their some good advantages. Zigbee is mostly used in Home automation systems and control.

Here's some advantages of ZigBee

  1. Chip-vendor independence
  2. Rapid innovation
  3. Extremely Low cost
  4. Open standards enable markets
  5. Easy to deploy
  6. Excellent performance in environments with low signal-to-noise ratio
  7. Appropriate range of operation (30 - 100 meters)
  8. Appropriate and reliable data transfer, bit rate : 250kbps at 2.4 GHz
  9. Very low power consumption
  10. Secure data transfer
  11. Zigbee protocol needs less than 64 kb of ROM and 2-32 kb of RAM
  12. Zigbee can bee implemented with any type of microcontroller

Saturday, December 11, 2010

gpsim - Open source simulator for Microchip PIC

gpsim is an open source simulator for Microchip's PIC microcontrolers. It supports all the three families of PICs. 12-bit, 14-bit, and 16-bit cores. The gnupic gpsim is distributed under the GNU General Public License. This software let you test the code for a microcontroller without using the real microcontroller by saving time and cost.

Distributor : Being free and open source, this software can be downloaded freely from the website of the software.

Home page : gpsim.sourceforge.net

Friday, November 26, 2010

Reading Datasheets Of Electronic Devices

Most of the present-day electronics designers and application engineers do not find it necessary to look beyond the first page of the datasheets of the electronic components or devices while selecting one for their application. They consider the knowledge of a few major specifications of the device sufficient for the design exercise that they wish to undertake. Though it may be adequate in some cases, the design where the components are chosen without giving due consideration to the information contained in the datasheet may not be the optimal one.

The datasheet of a device reveals its true character and hence its suitability for a given application. In addition to listing down the device parameters, it gives the electrical and environmental conditions at which these parameters have been measured and also contains information on variation of important parameters as a function of other relevant electrical and environmental parameters. It is vital information particularly when you are designing a circuit or a module that has to qualify stringent environment standards. A comprehensive datasheet almost invariably includes application circuits recommended by the manufacturer.

Nokia RTTL Frequencies (Hz)

Here's the Ring Tone Transfer Language (RTTL) for Nokia mobile phone for Octave 4 to Octave 7. RTTTL is a simple text-based format that you can use to create ring tones.to play music, all you need to do is to get the RTTTL ring tone of the particular music, then read its note and generate the frequency for the calculated duration.

No.
Octave=4 Octave=5 Octave=6 Octave=7
1 A 220.000 440.000 880.000  1,760.000
2 A# 233.082  466.164 932.328 1,864.655
3 B 246.942 493.883 987.767 1,975.533
4 C 261.626 523.251 1,046.502 2,093.005
5 C# 277.183 554.365 1,108.731 2,217.461
6 D 293.665 587.330 1,174.659 2,349.318
7 D# 311.127 622.254 1,244.508 2,489.016
8 E 329.628 659.255 1,318.510  2,637.020
9 F 349.228 698.456 1,396.913 2,793.826
10 F# 369.994 739.989 1,479.978 2,959.955
11 G 391.995 783.991 1,567.982  3,135.963
12 G# 415.305 830.609 1,661.219 3,322.438

Flexible Circuits - Advantages and Applications

Flexible electronics is a technology for assembling electronic circuits by mounting electronic devices on flexible high performance plastic substrates, such as polyimide. This post is about flexible electronics circuits advantages of flexible boards, and its emerging applications.

Thursday, November 25, 2010

Disadvantages Of HDTV

In the previous post, we discussed about HDTV and its advantages. But there are some issues - disadvantages with HDTV.

  • To be able to receive HD content, you need to have an HD-ready TV set or TV set with built-in HDTV tuner, which is comparatively expensive. Also, traditional SD programmes originally filmed in the standard 4:3 ratio, when seen on an HDTV monitor, will have empty margins to the left and right of the image because 16:9 wide-screen aspect ratio is the standard for digital HDTV. You can choose to fill this unused display area by stretching the SD shows horizontally to fill the screen, but this will only distort the image.
  • Normally, the HDTV transmission is provided through satellite and the same may not be available on free basis. In such a case, you may be required to subscribe to HDTV with the service provider.

  • HDMI, or component video cables, must be used to support high-definition signals. HDMI is an all-digital connection that allows both HD audio and video to pass through a single cable. If you use older video cabling standards like com-posite or S-Video for connections from a cable box or satellite dish, you will get only an SDTV-quality picture.

  • Another drawback of HDTV is that most of the operators do not fully follow HDTV specifications. So the HD picture quality is usually not as good as promised. Operators tend to use slower bitrates or lower resolution to accommodate more channels within the limited bandwidth, which reduces the video quality.

  • While on an analogue TV, the interference causes the picture to slowly deteriorate from bad to worse,
    interference in HDTV broadcast will freeze, skip, or display ‘garbage’ information.

What all is required for HDTV reception?

You may ask “Do I need a special TV to be able to see HDTV?” The answer is that only high-definition televisions can display HD content in the HD resolution. Enhanced-definition televisions can display HD content in a 480p resolution, which is DVD quality. All other televisions that are analogue of standard digital will not be able to display HD content in an HD resolution because they lack the technology to do so.

Sources of HDTV Signals

Therefore HDTV has the highest level resolution offered within the digital TV category. We can also infer that HD is digital, but not all digital TV is HD. HDTV has a 16:9 aspect ratio, which is the same as that of a movie
theater screen. This post describes the sources of High defenition TV signals. 

Tuesday, November 23, 2010

Working of Touch Screen Mobiles

  • What is the working principle behind touchscreen mobiles?
  • How do they differ from ordinary mobiles?
  • What are their drawbacks?

This post is intended to answer these kind of questions that usually arises in user minds.Mobile phones may use two types of input devices. In regular mobile phones, a keypad type of device is used, which is mounted separately from the screen of the cellphone. Whereas in touchscreen cellphones, a touch screen is a cellphone display screen that also acts as an input device. The touchscreens are sensitive to pressure; a user interacts with the mobile applications by touching pictures or words on the screen.

Difference Between Capacitor and Condenser

 There are always misunderstanding in the case of capacitors and condensers as many people considered these are same. But there are some differences between capacitor and condenser.

From electrical engineering point of view, condensers and capacitors are the same. However, you may often come across condensers also being referred to as devices used to condense vapour into liquid, a range of laboratory glassware used to remove heat from fluids, heat exchangers installed in steam-electric power stations to condense turbine exhaust steam into water, air coils used in HVAC refrigeration systems, a group of lenses mounted below the stage of an optical microscope to concentrate light, and condenser microphones that convert sound waves into an electrical signal.

Low Cost 32-bit Microcontroller Manufacturers List

32-bit microcontroller unit operates at very high operating frequency with low power requirement and low cost, thus catering to the needs of today's embedded devices. Heres the list of companies offering low cost MCUs in the market.
  1. Atmel
  2. Actel
  3. Freescale semiconductors
  4. Infineon
  5. Microchip Technology
  6. NXP Semiconductors
  7. Nuvoton Technology
  8. Renesas Electronics Corporation
  9. STMicroelectronics
  10. Texas Instruments

Advantage Of 32-bit Microcontrollers

This post shares the advantages of a 32 bit microcontroller unit (MCU) over 8bit and 16bit.

A design engineer from R&D department says that "Couple of years ago, we replaced our 8-bit design of the smart card terminal and fingerprint detection with 32-bit design. Our move was supported by the reduced price of 32-bit MCU. The major advantage we saw was reduction in the overall cost of the system due to decrease in component counts. 8-bit design almost used 18-20 peripheral chips, whereas 32-bit used only five to six chips. 32-bit microcontroller offers advantage of integrated peripherals like I/O lines, TCP/IP and USB along with high performance".

Monday, November 22, 2010

Where to by Electronic Components Online In India

This post describes where to by electronic components online in india safely. I found a safe list online to buy almost all components like capacitors, resistirs, IC's, microcontrollers, Microprocessors, Programming KIts, Soldering Irons etc.

Buying components online is not a fair choice if you had the components in your local store near you.However the componets that not available at local shops may get easily from an online shop. In india there are many online components distributers like www.kitsnspares.com which gives you a wide range of electronic Do It Yourself kits to support your creative ventures. Yes, kitsnspares.com is in in my top list of electronic components sellers online.



 
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