Ink Cartridges: Online, The Coolest Shopping Place

Online shopping sure has many different surprises for you. It is also certain that only online shop site are the ones that could give you the most unique offers you would not find in local stores. There are actually different reasons why local stores would only limit their offerings to people. First, the market is […]

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Grid Dip Meter

Only a handful of components are needed to build an instrument which is indispensable in any RF workshop: the grid dip meter or ‘dipper’. The main function of this clever piece of test equipment is to determine the resonance frequency of unknown tuned circuits within a certain range (typically, 1.5 to 80 MHz). Apart from […]

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Energy Storing Devices

Unfortunately, the sun may not shine just when you need electrical energy. The reverse is also true: energy may not always be required when the sun supplies plenty of it! In addition to the solar cell array, a stand-alone system requires another important component: an electrical energy storage device. The first device that comes to […]

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From Solar Cells to Solar Panels

A single crystalline solar cell supplies a no-load voltage of about 0.6 V, independent of its size. A cell made from amorphous silicon produces a slightly higher voltage of about 0.8 V. Under normal circumstances, i.e., assuming a normal cell size of 10×19 cm, the power output is relatively low at 1.2 to 1.4 Watt. […]

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Simple VU Meter

Most of us have over the years become familiar with the nervously moving pointers or LED bars of the VU (visual unit) meter on the front panel of a cassette tape recorder or mixing panel that indicate the level of the a.f. signal. A simple VU meter circuit can be purchased at various places – […]

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Houseplant Buzzer – When the Soil Gets Too Dry

Unless they are triffids (tall, prolific, carnivorous and venomous fictional plant species), outdoor plants are totally dependent for their welfare (water, sun and chemicals) on Mother Nature. Houseplants are not that lucky: they depend on man, who is often forgetful when it comes to watering or feeding them. To help such negligent owners/caretakers, at least […]

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Product Development

What Makes a Good Product Fundamentally, in our capitalist society, a good product is defined as being worth equal-to or more-than its selling price. It’s important to realize that ‘worth’ is a completely subjective measure. Consumers are satisfied as long as they feel their money was well spent. If not, they won’t buy from you […]

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