VU meter


The VU Meter ( Volume Unit Meter) is the simple analogue moving coil meter used in audio equipments to measure the intensity of sound in Volume Units (VU).The level of measurement is in dB and time in seconds. The design of the VU meter is based on the way by which human ear perceives sound in volume.VU meters are well suited to indicate continuous audio signals than the fast transient audio signals.

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STRING LED


String LEDs are now very popular as decorative lights which are available in different colors at very  low cost. It gives very brilliant colour display sequencing in four channels. The blinking pattern is controlled by a programmed chip and the switching is achieved by a high volt SCR .String LEDs show automatic Multi pattern changing display. Its working is really amazing and breaking all the conventional circuit designs. It shows that how a chasing and blinking light pattern can be created using a very simple method. Thanks to China technology  for giving such a simple and low cost decoration. Let’s open the tiny circuit box and see what is inside.

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Safety in PDF


The PDF is designed to keep up with today’s fast-paced and highly demanding work world. Portable Document Format files are safe in online activities because these are “Read Only” files that cannot be altered without leaving the Electronic foot print .This makes the PDF safe since it satisfies the legal requirements to stand up in a court of law.PDF file system was introduced by the Adobe systems in 1993 to make a safe file transfer in electronic media.PDF is equipped with Compression Algorithms which is used for compressing the graphics or images in the files. Algorithm makes the PDF file smaller and portable. TIFF, JPEG, GIF files etc used in web can be easily altered without leaving the electronic footprint, but it is difficult to manipulate PDF and the owner can make complaints if a manipulation is noticed.

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Mosquito Swatter


Definitely, mosquitoes are annoying and it can spread diseases also. The best way to destroy mosquito is electronic killing using Swatter. It eliminates the use of toxic chemicals. The mosquito coils and liquids do not kill mosquito but they repel them only. Mosquitoes will return back when the chemical disappears from the atmosphere. The swatter is commonly called as Mosquito bat and is meant for killing the mosquito and not for repelling. Since each mosquito lays thousands of eggs, destroying a mosquito equals  destroying thousands of mosquitoes.

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PIR Sensor


Infrared is the invisible radiation lies between the Visible and Microwave portions of the electromagnetic spectrum. The term Infra means below the ability to detect visually and the term Red means colour of the light with low energy level. The Near infrared is close to the red portion of visible light and the Far infrared is close to the microwave region. Far infrared is thermal and we feel it as heat by the temperature sensors in our skin. Short and Near infrared rays cannot be detected since these are invisible as well as cool. Active infrared rays are produced from semiconductor sources but natural objects like animals including human beings emit infrared rays from the body heat. Humans at normal body temperature emits Infrared rays at the wavelength of 10 microns.PIR Sensors are used in surveillance systems to detect moving persons in protected areas.



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