Docsity
Log inSign up
Docsity
Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity

Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips
Guidelines and tips
Sell on Docsity
Sell on Docsity
Log inSign up

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search Store documents

The best documents sold by students who completed their studies

Search through all study resources
Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

Earn points by helping other students or get them with a premium plan

Share documents
download point icon20 Points

For each uploaded document

Answer questions
download point icon5 Points

For each given answer (max 1 per day)

All the ways to get free points
Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

University Rankings

Discover the best universities in your country according to Docsity users

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

From our blog

Exams and Study
Go to the blog

summary of thermal energy, Summaries of Electronics

University of Bohol (UB)Electronics

The process of converting heat energy to mechanical energy and then to electric energy. It also describes the formation of electric potential on the material through PN junctions and the difference between direct and alternating currents and voltages. The document also includes diagrams and waveforms to explain the concepts.

Typology: Summaries

2018/2019

Available from 07/22/2022

spuarman
spuarman 🇵🇭

5 documents

1 / 19

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Thermal Energy
The production of most electric energy begins with the
formation of heat energy. Coal, oil, or natural gas can be burned
to release large quantities of heat. Once heat energy is
available, conversion to mechanical energy is the next step.
Water is heated to produce steam, which is then used to turn
the turbines that drive the electric generators. A direct
conversion from heat energy to electric energy will increase
efficiency and reduce thermal pollution of water resources and
the atmosphere.
pf3
pf4
pf5
pf8
pf9
pfa
pfd
pfe
pff
pf12
pf13

Partial preview of the text

Download summary of thermal energy and more Summaries Electronics in PDF only on Docsity!

Thermal Energy The production of most electric energy begins with the formation of heat energy. Coal, oil, or natural gas can be burned to release large quantities of heat. Once heat energy is available, conversion to mechanical energy is the next step. Water is heated to produce steam, which is then used to turn the turbines that drive the electric generators. A direct conversion from heat energy to electric energy will increase efficiency and reduce thermal pollution of water resources and the atmosphere.

  • Solar Cells
  • Solar cells convert light energy directly into electric energy. They consist of semiconductor material like silicon and are used in large arrays in spacecraft to recharge batteries. Solar cells are also used in home heating.
  • N type layer – the atomic arrangement results on a surplus of electrons which can move freely.
  • P type layer – the atomic arrangement has missing electrons in certain places. There is a hole where nearby electrons can jump in to fill it.
  • If you bring a N layer to a P layer together. Free electrons can move to from N layer to P layer to fill the holes.
  • PN junction form that produces an electric potential on the material.
  • When sunlight falls on that junction the light energy knocks an electron on an atom.

DIRECT AND ALTERNATING CURRENTS AND

VOLTAGES

  • Direct current (dc) is a current that moves through a conductor or circuit in one direction only (Fig. 1 - 9a). The reason for the unidirectional current is that voltage sources such as cells and batteries maintain the same polarity of output voltage (Fig. 1 - 9b). The voltage supplied by these sources is called direct- current voltage, or simply dc voltage. A dc voltage source can change the amount of its output voltage, but if the same polarity is maintained, direct current will flow in one direction only.
  • An alternating-current voltage (ac voltage) source periodically reverses or alternates in polarity (Fig. 1 - 10a). Therefore, the resulting alternating current also periodically reverses direction (Fig. 1 - l0b). In terms of conventional flow, the current flows from the positive terminal of the voltage source, through the circuit, and back to the negative terminal, but when the generator alternates in polarity, the current must reverse its direction. The ac power line used in most homes is a common example. The voltage and current direction go through many reversals each second in these systems.
  • The voltage is flowing in one direction. As the voltage increases the light bulb gets brighter, when it reaches its peak, the current stays the same, but the voltage begins to drop and the bulb gets dimmer. When the voltage reach (zero) 0 volts. The voltage polarity changes causing current to flow in an opposite direction.
  • The change from start to finish is called a cycle.
  • The rate at which the cycle repeats is frequency. It measured using the unit hertz (cycles per second)
  • In Philippines we used 60 hertz. It means the cycle repeats itself 60 times per second.

We use AC power because it can be easily step up or step down using transformers. Stepping up to hundreds of thousand of volts, we can transmit power at a lower current, it reduces power loss in transmission. Why we use DC power? We use Dc power in more complex electrical circuits because transistors or IC (integrated circuits). They need constant power source.