Bargraph Display

LM 3914 / 3915 / 3916 versions ICs are used in display circuits to drive either individual LED or Matrix LED. These are mainly used in circuits where precision output display is needed. Its each output becomes low one by one with the increment of 125 milli volts in the input. These ICs are used in Audio displays, Temperature meters, Decibel meters etc.

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Piezoelectricity is the ability of some materials such as crystals and certain ceramics, to generate an electric potential in response to applied mechanical stress or heat. If the piezo crystals are not short-circuited, the applied charge induces a voltage across the material.

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TV Guard

Here is a simple solution to protect TV from voltage surge through cable during lightning. It gives protection, if the induced current is not too high. The circuit uses only two Safety capacitors to limit the voltage entering into the antenna input of the TV. This can be also used in Modem cables.

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Environmental Scanning Electron Microscope –ESEM

The invention of Environmental SEM (ESEM) during 1980s allowed samples to be observed in low-pressure gaseous environments of 1-50 Torr and high relative humidity. This was made possible by the development of a secondary-electron detector capable of operating in the presence of water vapour and by the use of pressure-limiting apertures with differential pumping in the path of the electron beam to separate the vacuum regions around the gun and lenses from the sample chamber.The first commercial ESEMs were produced by the ElectroScan Corporation in USA in 1988

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Photodiode Design

Photodiode is a type of light detector capable of converting light energy into either current or voltage, depending upon the mode of operation. Photodiodes are similar to typical semiconductor diodes except that they may be either exposed or packaged with a window to allow light to reach the sensitive part of the device.

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