TLE reviewer on Electronics

TLE REVIEWER

I.

Thermoelectricity A. Seebeck Effect (Thomas Seebeck)  Production of electric current containing different metals kept at different temperatures.  Thermocouples-device for measuring temperatures in which 2 wires of different metals arejoined and opposite temperatures are applied on the junctions and it will produce electricity B. Peltier Effect (Jean C. A. Peltier)  Production or absorption of heat at the junction of two metals when an electric current is passed from one metal to another. C. Thomson Effect (William Thomson)  If a temperature difference exists between any two points of a currentcarrying conductor, heat is either evolved or absorbed depending upon the material D. APPLICATION  The combined cooling/heating ability makes them attractive for many electrical energy generation and cooling application

II.

Thermo Electric Generators (TEG) 

III.

Thermo Electric Modules (TEM)  

III.

Performs the same functions as an engine-powered electric generator -Similarities: Both produce practical electricity. Both reliable. -Difference: TE unit is silent and has no moving parts except a small cooling fan

No moving parts;rugged, reliable, and wuiet heat pumps Insufficient, little power is produced

Battery 

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Device that converts chemical energy into electrical energy o Electrolyte  Ionic conductor  One of the electrodes will react producing electrons, whole others will accept electrons When a battery is connected by wires to a device such as light bulb, the acid paste begins to act on the metal. The carbon rod becomes positively charged. As a result an electric current runs through the paste and into the wires outside the cell or battery. Consist of: o 2 electrodes of different materials o An electrolyte between electrodes

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IV.

Solar Energy 

V.

Chemical Energy o Wet cell  Acidic liquid(diluted sulfuric acid)  Electrodes of Lead dioxide and spongy lead o Dry Cell  Acidic paste  Zinc  Carbon electrodes Battery Types o Rechargeable/Secondary cell o Non-rechargeable/Disposable batteries/Primary cell Solar electricity is created using Photovoltaic (mostly silicon) technology by converting solar energy form sunlight to solar electricity

Mechanical Source 

When a wire is moved in a magnetic field, an electric current is generated in that wire Magnet + Copper wire + motion= Electricity AC generator- without commutator DC generator – with commutator

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I.

Electron Theory 

The continuous flow of a stream of free electrons along a conductor.

A. Continuous flow o o o

Energy is always present Blackout-malfunction in the Power Station, NAPOCOR cuts power supply Brownout-a partial blackout

B. Stream o o o

Body of water; flows in 1 direction Electricity flows from negative to positive Electrons are the only ones that can move because they are lighter and smaller

C. Free Electrons o

Electrons that can be forced out from its orbit by bumping into another free electron