This document discusses different types of electricity including direct current (DC), alternating current (AC), and how they are generated. It then covers how electric energy is measured in joules and calculated based on voltage, current, and time. Electrical power is defined as the capacity to transform energy over time and is measured in watts. Power and energy are also related through the calculation of energy equaling power multiplied by time. The document concludes by mentioning some common electronic components like resistors, capacitors, and diodes.

1. More about electricity an electronics Unit 6 continuation

2. ALTERNATING AND DIRECT CURRENT: AC DC

3. DIRECT CURRENT It’s the type of current, we get from batteries. IT’ S ALWAYS THE SAME

4. ALTERNATING CURRENT IMAGINE A BATTERY CHANGE BETWEEN THE POSITIVE TERMINAL AND THE NEGATIVE. ALTERNATING CURRENT is the type of current we get from a plug or the main supply. WE DON’T GET ALWAYS THE SAME VALUE, BECAUSE ELECTRONS CHANGE THE SENSE OF THEIR DIRECTION. THEY CHANGE IT 50 TIMES A SECOND.

5. WHY WE USE ALTERNATING CURRENT? Because this kind of electricity is easier to transport than the direct one

6. ELECTRIC ENERGY

7. What was voltage? The energy that gives a battery to the electrons to keep then moving through the wire.

8. This energy is given to a bulb, a resistor, a buzz, ... In these components is transformed into another way of energy.

9. How can we measure this energy? The energy that is consumed by an electrical appliance is calculated knowing the current(I) that pass through it, the voltage (V) that supports and the time working (t): E = V · I · t Unit: Jule, J

10. Something about electrical appliances Motors transform the electricity in movement Bulbs transform the electricity in light Resistors transform the energy in heat, so they are used in heaters

11. ELECTRIC POWER

12. The capacity of an electrical appliance to transform energy in a period of time. UNIT: Watt, W It can be calculate by : P = V ·I

13. How can be related energy and power? Once we know the power of a receiver, it’s easy to calculate the electric energy consumed by it: E = P · t

14. El kilowatio hora y la factura de la luz If you express power in Kw and time in hours, you will get a new unit to energy, kwh. These is the unit that measure the consume of energy at home.

15. ELECTRONIC COMPONENTS

16. RESISTORS

17. Variable resistors o potentiometers It’s a kind of resistor with a value that can be adjusted between a cero and a maximum value given by the manufacturer

18. Resistor that depends of a physical property Light Dependent Resistors, LDR, the more light it receives, the less resistor it has. Thermistors: NTC (Negative Temperature Coefficient), the resistor decreases when the temperature increases PTC (Positive Temperature Coefficient), the resistor increases when the temperature increases

20. CAPACITORS

21. DIODES