TAOSINC which is a division of Texas Instruments has their own line of devices which specialize in light sensing or light to voltage conversion.

TCS230 - 4-Channel Light to Frequency
TSLB257 - Blue light to voltage converter
TSLG257 - Green light to voltage converter
TSLR257 - Red light to voltage converter

A qoute from the TAOSINC RGB LTV sensor page:

“The integrated color LTV sensors combine a photodiode, color filter, and transimpedance amplifier on a single die. The output is then fed to an ADC for digital processing. TAOS’ solution requires fewer components, saves board space and reduces assembly cost over a discrete photodiode approach. TAOS’ solution also simplifies design and board layout because sensitive analog circuitry is integrated on-chip, which also improves the noise immunity. The Color LTV devices are ideal for applications such as colorimetry, printing process control, display color correction, and selectively ambient light detection or rejection. ”

Some electronics companies offer free sample products for evaluation and testing. The free sample products may range from wires, switches, LEDs, logic gates, analog ICs  and microcontrollers. If you know some of these companies, then you may have noticed that most of them are not shipping to Philippines. Why are they not sending free samples to Philippines?. Actually, some of them did send free samples to Philippines but only for a limited time. Most of these companies would ban countries which resell free sample products or abuse the free samples program by ordering too many products in such a short period of time. Fairchild Semiconductors used to send tons of LEDs, seven segment displays and  phototransistors to Philippines. Fairchild semiconductors noticed that there were too many orders coming from Philippines in a very short time and some Juan Dela Cruz is using too many addresses so that he can order more free samples and resell it to his fellow students. To add insult to injury, there are reported cases of electronics store asking for free samples and selling free sample products on their stores as brand new Class-A items. Free samples are not guaranteed to work as the commercial version and do not have guarantees that they would work as specified. If you ever find a company that do send free samples to Philippines, my advice to you is to keep it as a secret or share it only to your friends whom you know that is not abusive and would respect the rules of the free sampling program.

Good luck to all ECEs that are going to take the board exam.

Check this out from Cooljag USA
http://www.cooljagusa.com/miniflash.html

A PC fan that can display messages as its propeller
rotates. You can program the fan with your own custom message with up to 128 characters.  It is available in the following configurations:

80 X 80 X 25 mm 1700RPM 23 CFM
90 X 90X 25 mm 1400 RPM 28 CFM
120 X 120 X 25 mm 1100 RPM 49 CFM

On the thread http://www.electronicslab.ph/forum/index.php?topic=976.0 entitled “How many amps can the telephone line supply?”. It was demonstrated by our member “Born2BeWired” that we can actually use the phone line as a power source for LEDs. The telephone company has an independent power source which in most cases more reliable than our power company. This is specially true when we are talking about electric cooperatives operating in the province. Just in case we have brownouts, we could take advantage of the electric current supplied by the phone company and use it to power our white LEDs.

Here are the pictures and schematics:

Yes it works and it is called phototherapy. Acne is caused by the inflammation of the oil gland as a result of blocked pores and bacterial infection. The bacteria responsible for acne can be killed by exposing the skin to blue light coming from an LED with a wavlength of 405nm-420nm. To hasten the healing of an infected oil gland, the skin is exposed to red light with a wavelength of 655nm-665nm ( Red ). The combination of blue and red light exposure helps in the reduction of pimple size and redness. Phototherapy study is published under the British Journal of Dermatology 142 (5), 973–978 and on the Mount Sinai School of Medicine under David Goldberg.

Light emitting diodes as we know serve as light sources or photon generators. Photons are generated on the depletion region where electrons and holes recombine. The PN junction of LEDs also generate electrons and holes when exposed to light. As demonstrated on this experiment, a green LED is connected to a red LED in parallel connection. The green LED is exposed to the beam of a green laser pointer and generates a small current that is enough to turn on the red LED. This experiment demonstrate that LEDs can also function as a solar cell though less efficient compared to commercial ones.

The following members would receive 1 “Renesas Starter Kit Plus” microcontroller evaluation board.

1. Member with the highest number of post: “Paranz”

2. Member who started the longest technical thread: “glutnix_neo”

3. Best poster award: “zer0w1ng”

4. Active member referral: “No Winner”

If you are a beginner in PIC programming the best thing for you would be to start programming PIC in BASIC language. Why use BASIC ? Because the syntax is easier to remember and understand. A very good resource site for studying pic programming in the BASIC Language is the site of MIKROE:
http://www.mikroe.com/en/books/picbasicbook/00.htm ( “Programming PIC Microcontrollers in BASIC” ).

The free online book about MIKROBASIC is arranged from the elements of the BASIC language up to controlling LCD displays.

The new fuss today is all about these expensive UV flashlights costing around 30$ to 100$, even the 5mm UV LED discretes are still expensive which cost around 300-600 pesos here in the Philippines. The common application of this gadget is to act as an excitation source for fluorescent or luminous materials. UV flashlights are used in currency validation to identify genuine or counterfeit paper money, mineral and substance identification, excitation source for glow-in-the-dark objects, forensic investigation and fluid leak detection. Extra care must be taken when using LED flashlights because UV is harmful to the human eye.