Remember the good ole days when all you had to do is snap, print and wave around film as if you were fanning yourself? Well, with the increase of digital camera products and the dying demand for such a camera…the once popular Polaroid discontinued it’s line of film packs over a year ago. In its effort to provide “instantaneous” prints, Polaroid has introduced the PoGo. Prints are 5×7 cm on a specialized paper. The PoGo is currently on the market….let’s see if it’s popularity follows the path of its very successful predecessor.
Archive for August, 2009
Radio Frequency (RF) communication protocols have been growing in both media popularity and real-world applications for many years. Most consumers have probably heard of or are even familiar with terms like GSM, TDMA, CDMA, UMTS, IEEE802.11/WiFi, IEEE802.15.4/ZigBee, WiMax, MiWi and a host of others. These are all terms or acronyms for different industry-standard RF communications protocols that have enjoyed commercial success. One of the main reasons RF communications is attractive to consumers is that no wires are required to connect from on system to another. For example, when cell phones first started offering hands-free headsets, they were connected to the phone via a connector and a wire from the earpiece/microphone. Now most new mobile phones include Bluetooth wireless connectivity built-in. One can buy a Bluetooth-enabled wireless headset and it automatically synchronizes with the phone, enabling one to talk on their mobile phone wirelessly while the phone is in a pocket or purse. This wireless connectivity is very convenient.
Another technology used for wireless communication is infrared or light waves. An example of a very simple application using infrared technology is a TV remote control. In the remote control there is an infrared (IR) Light Emitting Diode (LED) that shoots IR light pulses towards the TV. On the TV, there are IR photodiodes that receive the light pulses and convert them into digital signals that tell the TV to change the channel, increase/decrease the volume, or any other command necessary to adjust the TV without getting up from one seat.
One industry-standard wireless communications protocol that uses infrared light as it communication medium is IrDA. This protocol was implemented in laptop PCs, mobile phones, smart phones and PDAs long before RF protocols like WiFi or Bluetooth were the norm. IrDA is also implemented in scanners, printers, keyboards, mice, cameras, scanners, vending machines, payment systems, etc. There are some useful advantages to selecting IrDA as a wireless connectivity solution and some of the key ones are shown below.
• IrDA is inexpensive to implement. Free IrDA stacks are available from numerous MCU suppliers and IrDA transceivers are << 1.00usd in volume.
• No regulatory restrictions for use of the infrared frequencies used by IrDA
• No Radio Frequency spectrum power output restrictions or fees
• IrDA has fast data transfer rates (currently up to 16Mbps and soon much higher)
• IrDA is Secure. Light waves are focused and directional which makes snooping difficult. Line of sight is required from transmitter to receiver to connect. In addition, infrared light cannot go through walls or objects.
While industry-standard RF wireless protocols have become standard on many large volume consumer applications today, the fact remains that IrDA is secure low-cost, convenient cable replacement technology that is an excellent choice for many applications. This is especially true for applications that are sensitive to cost, regulatory restrictions and/or fees, or security of data transfer.
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Sony has announced a new type of lithium ion rechargeable battery that greatly improves power and life performance (better stability for fewer exploding laptops of course).
The Olivine-type lithium iron phosphate used is a perfect cathode material due to its robust crystal structure and stable performance, even at high temperatures. These batteries have a high power density of 1800W/kg, and extended life span of approximately 2,000 charge-discharge cycles.
It is claimed that these new batteries will provide 80% capacity retention after those 2,000 charge-discharge cycles is also able to charge in a half hour. Power tools is an ideal use,where then it will gradually infiltrate its way to consumer electronic electronic devices.
More here
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If you have interest in the previous post on overvoltage protection (OVP) let us suggest the recently introduced family of battery chargers, the MCP73113, MCP73114 and MCP73213 Lithium-Ion (Li-Ion); and MCP73123, MCP73223 Lithium Iron Phosphate (LiFePO4) 1.1A Chargers, all have built-in Overvoltage Protection. The devices have a maximum input voltage of 18V and come with various OVP set points—5.8V and 6.5V for the single-cell MCP73114 and MCP73113/23 chargers; or 13V for the dual-cell MCP73213 and MCP73123 chargers.
To provide more flexibility, the MCP73113, MCP73114 and MCP73213 devices provide a variety of charging-voltage options for Li-Ion batteries—4.1 to 4.4V for the single-cell and 8.2 to 8.8V for the dual-cell devices. The MCP73123 and MCP73223 devices target LiFePO4 batteries, and offer charging-voltage options of 3.6 and 7.2V, respectively.
With the option for various charging voltages, it is possible to target different batteries depending on their requirements. The LiFePO4 option provides designers the flexibility to try out one of the up-and-coming battery technologies with built-in smoke release resilience and higher current capabilities.
For more on these chargers, head on over here
We have all heard the horror stories of laptop batteries blowing up or favorite tunes players burning a hole through someone’s jeans. The reasons for the magic smoke escapes vary from poor battery cell construction to overheating and poor charging mechanisms, yet all agree: magic smoke should stay inside our electronics. While it is up to battery manufacturers to cage the magic smoke inside the batteries, plenty can be done outside the battery to prevent smoke escapes from other parts of the electronic device.
Case in point: Overvoltage Protection (OVP) on a battery charger circuit. OVP allows the battery charger to shut down in case the input voltage goes too high and prevents the circuit from overheating. And, as we know, overheating is smokes’ most notorious escape accomplice. The value added by battery chargers with this feature is fast making it a standard so in your next design make sure OVP is on the feature list.
The open-loop response of an operational amplifier provides insight into it’s performance. Two important specifications in Open-loop , i.e. no feedback, are:
1. DC Gain – the gain at DC. ( The higher, the more accurate the amplifier is )
2. First-Pole Frequency, fp1 ( the frequency where the open-loop begins to fall)
A direct result of fp1 and the DC Gain is the Unity-Gain Frequency, fu. This is the frequency where the open-loop gain falls to 1 V/V. The greater the fu, the faster your op amp can respond to input signals. This leads us to Microchip Technology’s most recent and fastest op amp to date.
Yes, there exists faster op amps in the industry, but it is still a significant step for Microchip , who are showing that they have the know how to design as well as any of the analog companies out there. Along with auto-zeroed and auto-calibration (mCal) op amps, they have just recently announced a family of amplifiers featuring 60 MHz of gain bandwidth product and high output current drive of 90 mA. These amplifiers are optimized for high speed, low noise and distortion, single-supply operation with rail-to-rail output and an input that includes the negative rail. This family is offered in single (MCP661), single with Chip Select (MCP663), dual (MCP662) and dual with two Chip Select pins (MCP665).
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