The 3 Different Types of Printed Circuit Boards

If you've ever used a computer, pager, cell phone, or any other device requiring electronic components, then underneath all of those layers of metal you will eventually find a printed circuit board. Printed circuit boards (pcbs) have been used for more than 40 years, but today's models are so technologically-improved that they bear only the most basic resemblance to their forebears. Here's a little information about the 3 different types of printed circuit boards.

1. Single-sided board: Adequate for simple games and other non-complex electronics, a single-sided board is compromised of just one substrate with a fairly straight-forward set of components. An extremely thin layer of conducting material is applied to the board and electronic components are soldered to a set of interconnecting circuits. A series of contact fingers along the edges of the board serve to either connect this PCB to another or to a power source.

2. Double-sided board: As its name implies, an increase in application complexity may make it necessary for additional electronic components to be soldered to the other side of the substrate. Now that there are circuits on each side of the board, the components are connected via a series of strategically placed through-holes which allow for an unimpeded electrical connection between the two. The holes must therefore be coated with a conductive material to allow the PCB to work correctly.

3. Multi-layered board: With these printed circuit boards, the substrate is actually compromised of multiple layers of printed circuits. Separated by layers of specialized insulation, these printed circuit sheets are also connected via plated holes and allow for more complex applications.

pcbs have revolutionized our world in so many ways that their influence is mind-boggling. Improvements in manufacture procedure as well as technology are continually evolving; so much so, perhaps, that in another 40 years they just may bear no more than a passing resemblance to today's models.

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Reuse of Unused Mobile Phones

Increasing government regulation coupled with force to reduce the environmental defects from unused is not really a bad thing. Hazardous materials are banned throughout our society. Hazardous waste management is often considered as a complicated process; still the producers and other well developed organization take the responsibility for the recycling. Mobile phone sectors are one of the fastest growing industries in the world. According to a survey the life of a mobile phone is only 18 months with the arrival of a new model in the market. This leads to the junk storage of old phones in their drawer. To minimize the volume of bulk amount of ending up in landfills, recycling of them is mandatory.

Typical disposal of the unused or their accessories result in one of the following alternatives:

- Reuse
- Product upgrade
- Material recovery
- Waste disposal.

Reusing deals with the reselling or reusing the products. Product upgrade is to repair, remanufacture, refurbish and repackage. Material recovery is recycling and reduction in sales volume. Waste disposal includes incineration or land filling the waste products.

Mobile phones have a number of components which have a clear ability to remanufacture them. Integrated circuits, printed circuit boards, gold-coated edge contacts on the circuit boards, microphones, the protective housing around them and keyboards can be recovered and reused. Recycling companies promises that their recycling will be environment friendly with nothing going into the landfills.

Consumers who are willing to get a new model can hand over their old phones to the retailers for recycling instead of keeping them in their drawer. There are a lot of persistent bio-accumulative toxins in the circuit board of the mobile phones. Once when they are thrown in the lands without giving for recycling, they pollute the soil and the underground water. The most important hazardous metal in the circuit board of the mobile phones are the lead. When they are thrown in the land they pollute the drinking water, this causes kidney problem, affect the immune and nervous system too.

Lead is threatening more when compared to other metals in the circuit board. The interesting fact is that, gold in the circuit board can be recovered and used. Recovering them by one's own effort is dangerous. So donate them to the recyclers and be paid. Recycling them not only conserve energy and environment, but also reduce the basic raw materials required to manufacture a new one. They also reduce the air and water pollution too. Focus all your attention in recycling them in a charitable way, such that a community benefit from it. Recycling of mobile phones can become successful when people donate their old phones for recycling. Donate a mobile phone for recycling and become eco-friendly.

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What is EEPROM ?

EEPROM stands for Electrical Erasable Programmable Read Only Memory and also referred to as E²PROM. As the name suggest, an EEPROM can be both erased and programmed with electrical pulses. Since it can be both electrically written into and electrically erased, the EEPROM can be rapidly programmed and erased in circuit for reprogramming without removing them from the circuit board.

EEPROM is also called a non-volatile memory because when power is turned off the stored data in the EEPROM will not be erased or intact. New EEPROM have no data in it and usually have to program with a programmer before it can be use. Information stored in this type of memory can be retained for many years without a steady power supply.

What is the function of EEPROM? EEPROMs are used to store user programmable information such as: -

o VCR programming information

o CD programming information

o Digital satellite receiver control data

o User information on various consumer products

EEPROM in monitor performs two functions:

o When a monitor is switch on it will copies all data or information from the EEPROM to the microprocessor. For example, the EEPROM will let the microprocessor know the frequencies at which the monitor is going to operate.

o The EEPROM is used to store the current settings of the monitor. The settings of the monitor will not be erased even when the monitor is turned off. Anytime a change is made in the monitor settings, the microprocessor updates the setting in the EEPROM. When the monitor is turn on again, the stored settings are used to set up the monitor for operation.

What are the symptoms if the MONITOR or TV's EEPROM data is corrupted or damaged?

o No high voltage (no display).

o Horizontal or vertical frequencies run.

o Cannot save (store) current setting.

o Certain control functions like sound, brightness and contrast control does not functioning.

o On Screen Display (OSD) does not function or the OSD have a corrupted display.

o High voltage shut down (EEPROM set the horizontal frequency way too low or twice the line frequency perhaps leading to failure of the horizontal output transistor (HOT)).

What is an EEPROM programmer or copier?

EEPROM seldom fail, they just lose or have their memory (data) corrupted may be due to high voltage and static discharge from a monitor. Once reprogrammed they are as good as new. As mentioned earlier, new EEPROMs are blank and need information or data to be loaded in order for it to functions. The job of copying the data into an EEPROM is done by a programmer or a copier. Programmers comes in all shapes and sizes. You can copy these devices for repair replacement only. You cannot copy them for resale without a letter of approved from the vendor who produced them. There is quite a number of companies selling EEPROM programmer:

Typical EEPROM part no:

24C02, 24C04, 24C08 etc

24C325, 24C645AT17C65, AT17C128 etc

93C06, 93C46, 93C56, 93C66 etc

25010, 25020, 25040 etc

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Board Cameras - An Introduction

Board cameras are tiny cameras with the lens mounted on a circuit board. They come in very small sizes which make them ideal as security cameras or hidden cameras. They can be used as static surveillance cameras or as mobile hidden cameras for public recording. In fact, some of these cameras make use of pinhole lenses, which are very small in diameter. Pinholes are especially useful because only the rest of the camera need not be exposed in order to record - only the pinhole needs to be exposed.

Pinholes typically come in two categories: flat pinholes and conical pinholes. Flat pinhole lenses are used for materials such as film covering or fabric. Conical pinhole lenses need smaller holes and are usually used for static installations such as in ceilings or high posts. Pinholes are generally useful as any other kind of hidden camera but it comes with a trade-off: the resolutions it offers are slightly lower than that of standard board camera lenses which have a much larger diameter than that of pinholes.

Board cameras make use of two camera system technologies: CCD or charged couple display; and CMOS or Complementary-metal-oxide-semiconductor. CCD changes the light that enters into the lens into electricity which is then transformed digitally into information that is essentially picture data. CMOS also operates in the same way as CCD but has a few advantages over CCD - CMOS has a wider range of functions, can be made in smaller sizes and have an overall lower power draw. However, CMOS also has a disadvantage in that it can't match the image quality of CCD sensors.

Board cameras are typically plug-and-play which means that they can be directly connected to a TV, VCR or even personal computers. They use AC adapters to operate. However, some of these cameras also operate wirelessly, making use of batteries. Wireless board cameras have different transmitter and receiver configurations which can be utilized depending on the applications they will be used for.

Board cameras have very few moving parts, which mean that the applications they can be used for is already very limited. Also, they have a short focal length which produces a wide angle of view.

Overall, board cameras are ideal choices for static camera system applications such as surveillance cameras at stationary points like checkpoints or at building entrances. Their wide angle view also helps their case as static surveillance cameras. They are also good for discreet surveillance - their small size makes them extremely easy to conceal and they can also operate wirelessly, which is a major advantage. They can also be used for a broader range of applications such as for school projects, or can be used in conjunction with other pieces of hardware. These cameras also have their advantages over other types of hidden cameras such as their very small size, low power requirements, relatively cheap cost, and relatively easy installation and operation. However, they also have their own distinct disadvantages such as lower resolution and mediocre image quality. There are many choices for hidden cameras and board cameras are undoubtedly one of the best.

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How to Repair a Water or Liquid Damaged PCB

Printed Circuit Boards (pcbs) that are subjected to a high current short-circuit due to their contact with conductive liquids like water can be repaired. Water damage also causes salt crystallization and corrosion due to the continued exposure to water vapor. This crystallization of salts results in short circuits when the PCB is reactivated. The first thing that you should do is remove voltage sources such as batteries and mechanical/electro-mechanical components like relays, switches and potentiometers from the water-damaged circuit board. However, short circuits that cause components to blow up result in extensive damage. These parts need to be removed and reinstalled.

To remove congealed salts and other contaminants you need to immerse the PCB in an ultrasonic cleaner using an appropriate cleaning solution for several hours. Using industry-standard chemical solutions and cleaning agents in an immersion bath is the best way to remove all the contaminants. The cleaning process for water damaged circuits needs high frequency cleaning using high-powered ultrasound to eliminate all traces of water and crystallized residue from the board. Computer circuit boards and electronic devices contain metal and fiberglass. Water and other liquids result in corrosion when the power supply is not cut off. After rinsing and inspecting the board, it can be cleaned manually using a brush to ensure that everything looks good.

There are a few important things to keep in mind if you ever happen to spill water, tea or coffee on your cell phone or laptop keypad. Disconnecting the device is the first thing to do as devices may either explode or you might get an electric shock if you leave it connected to the power supply. You must remove the battery to stop the corrosion process.

Disassembling the device on your own to some extent is fine as long as you do not use excess force and cause further damage to the components. Depending on the extent of damage some components on the board may need to get replaced too. Using a small brush like a toothbrush is a good way to eliminate the maximum amount of liquid carefully. You cannot rely on the natural process of evaporation to dry your phone and laptop. Using a can of compressed air or a desiccant is a good option. Silica gel is an excellent agent that removes all the moisture in no time.

High pressure showers and massagers get rid of the liquid on the PCB. The board should be cleaned immediately. Leaving the liquid to dry before rinsing it with a suitable solution is not a good idea. The best thing would be to use kitchen paper to dry the wet spots with minimal pressure. A warm radiator can also be used for 12 hours to dry the PCB. Though many people resort to the use of a hand dryer to speed up the drying process, this causes irreparable damage to the PCB as the pressure of the dryer forces moisture deep into the board and into the smaller components. Solvents like chemical gasoline, pure alcohol, 90% isopropyl alcohol, distilled and deionized water are useful.

Once the PCB is thoroughly dried you can now attempt to get the device working again. Replace any of the damaged components, connect everything back together, and power up the device. In all probability your timely action will have saved your device from becoming another useless electronic brick.

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The Flashy New Wii Afterglow Remotes

So you've had your Wii game system for a while now and you are frankly getting tired of the plain jane look of the all white console and the all white Wii accessories that Nintendo makes. Sure, there are a few colored Wii accessories available made by third party manufacturers like CTA Digital and Intec, and even Nintendo came out with the pink and blue wiimotes in February, but by and large most all accessories for the Wii have been white and boring.

That is, until now. The latest offering from PDP is a set of colored, lighted, even glowing in the dark Wii remote controllers and nunchuks. These are called the Afterglow remotes. More specifically, the remotes and the nunchuck are made from clear polycarbonate plastic with a colored circuit board inside. Added to this are either red, blue, or green led lights that match the color of the circuit board and make the whole device "glow." It is all very cool and futuristic looking. Plus, you can see your wii remote or nunchuk in the dark!

On the Wii Afterglow Remote, several of the buttons have been moved and altered a bit as well. The one and two buttons are now tiered to give a slightly retro controller feel to the remote. Also, the plus and minus buttons are located above the A button. While I find the new location of the plus and minus button to be advantageous because of the way I hold the Wii remote anyway, I can see how others might find it inconvenient. But, I think most users will like the enhanced feel of the 1 and 2 buttons.

The Afterglow Remote has several lighting modes including off, on and the "acceleration" mode. I like the acceleration mode though I suspect that this will wear down the batteries faster. I don't know, I'm just guessing. And each of the remotes comes with color matched wrist strap so you don't throw your new prize Wii accessory through the window when you are playing Wii tennis.

Overall, the Afterglow remote controllers are a welcome new accessory to the already burgeoning assortment of accessories that are available for the Wii console. They are great looking, they perform as well as the standard Wii remotes in the games I play, and they will certainly turn all of your friends' heads the next time they come over for some Wii gaming.

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A method for recovering data from a hard drive death

Here's the situation. A laptop computer comes to us with a dead hard drive. Unfortunately, the user needs some files from the hard dead. After much research on the Internet and a couple of quotes from data recovery, we decided to try to retrieve information about ourselves.

Fortunately for us, the disc does not work at all. I say fortunately, because the usual problem is that the printed circuit on the bottom of the disk went bad. This does not mean that something does not work, butreplacing the circuit is the easiest thing to try.

The first thing needed is another hard drive. This may sound easy, but it is not. You need a hard drive anyway, and I mean identical with the same model number, part number, firmware, everything. In our case we had a Hitachi Travelstar hard drive that had three numbers match. The large number have been the model number, part number, and the number of MLC. I think the number MLC has something to do with the firmwarereview, but do not quote me on that. After speaking with Hitachi has referred me to a company called CueTech. They specialize in finding "hard to find, or obsolete computer parts. The burden wanted between $ 200 and $ 400 for the player, I thought it reasonable for the work required to find one. Instead of using I decided to look for myself and after two days, had not yet found another player for sale that meets my needs. We then started searching the house for laptops and similarwho had a blank disc. We are now in operation.

Now that we've had our training, we need to protect ourselves, because you wanted their car back in running order. So before you start any work we made a ghost image of their hard drive. After waiting 20 minutes or more to safeguard the end we started the operation. First, we removed the hard disk of work system and placed on a static pad with the circuit in place. We then used a Torx T-5lead to remove the screws that secure the circuit on the hard disk. The reader may need a different size or type of screwdriver. We then repeated the operation on the wrong disk. We put the circuit from the floppy drive and put the right people in the handset. Here we go! Once we have a new, we worked then configure the system to do a quick disk image. After waiting 20 minutes we had a bad image of the hard drive and our datawas recovered.

To complete the process, we had to put the circuit back to the good original hard disk and make sure it works properly. Once that is complete and the laptop returned to its owner, we installed a new hard drive in the system that had the original problem. The last step was to restore the disk image to the new hard disk, make sure it worked, and give the laptop to the owner.

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