1. PELTIER CELL • A Peltier Cell is device which directly convert heat energy into electric energy. Peltier device consist several of thermocouples. The thermocouple have two thermo elements that spreads between the hot side and cold side of the device.

Fig. 1.1

• The efficiency of this device is around 5-8 % (Wikipedia.org).Generally, older devices are made from bimetallic junctions.it was very bulky. But, now a days highly doped semiconductors are used which is made from bismuth telluride (Bi2Te3) and lead telluride (PbTe).

Practically Peltier cell working based on three effects
1) Peltier effect.
2) Thomson effect.
3) Seebeck effect.

1) Peltier Effect:

• If we applied voltage to peltier unit then the heat is transferred from …show more content…
When heat is applied to one of the two conductors or semiconductors, heated electrons flow toward the cooler one. If the pair is connected through an electrical circuit, direct current (DC) flows through that circuit.

Fig.1.4
• The voltages produced by Seebeck effect are small, usually only a few microvolts per kelvin of temperature difference at the junction. If the temperature difference is large enough, some Seebeck-effect devices can produce a few millivolts.

• Numerous such devices can be connected in series to increase the output voltage or in parallel to increase the max. Deliverable current. Large arrays of Seebeck-effect devices can provide useful, small-scale electrical power if a large temperature difference is maintained across the junctions.

• The Seebeck effect is responsible for the behaviour of thermocouples, which are used to approximately measure temperature differences or to actuate electronic switches that can turn large systems on and off. This capability is employed in thermoelectric cooling technology. Commonly used thermocouple metal combinations include constantan/copper, constantan/iron, constantan/chromel and constantan/alumel.
2. BOOST …show more content…
Filters made of capacitors (sometimes in combination with inductors) are normally added to the output of the converter to reduce output voltage ripple. Dimension:
• PCB size: 17.55mm * 25.22mm * was 5.85 mm and (no usb the height)
• En bloc Size: 17.55 * 32.53mm * 8.3mm (with usb height)

Features:
• Input Voltage: 1V ~ 5V.
• Output Voltage: 5V.
• Output Current: 500mA.
• USB Female Versatile.
• High Conversion Efficiency, Up to 96%.
• Ultra-small size, Installed in a Variety of Small Equipment.
• With Working Lights. 3. VOLTAGE REGULATOR (IC 7812)

Fig.3.1
Description
• The LM78XX/LM78XXA series of three-terminal positive regulators are available in the TO-220/D-PAK package and with several fixed output voltages, making them useful in a Wide range of applications. Each type employs internal current limiting, thermal shutdown and safe operating area protection, making it essentially indestructible. If adequate heat sinking is provided, they can deliver over 1A output Current. Although designed primarily as fixed voltage regulators, these devices can be used with external components to obtain adjustable voltages and currents.

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