Card Set Information

2013-04-03 21:24:30

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  1. Define:Battery
    • Source of voltage to push current through a circuit.
    • Consist of two or more cells in which a chemical reaction provides energy to electrons in conductors (electrodes) that are immersed in the chemicals (electrolytes) in cells.
  2. Define:Cell
    • Supplies electrical current.
    • Some call it the battery, but techniquely a battery has more then 1 cell.
  3. Define:Capacitor
    • Componant that accumulates & opposes charges in voltage, storing electrical energy in an electric field.
    • The letter F denotes capacitance, which is measued in farads.
    • Two metal plates or curved surfaces close together that are seperated by an insulator make up a capacitor.
    • Two types of capacitor are polarized capacitors (connected the correct way in circuit) & variable capacitors (often used in radio tuning circuits).
  4. Define:Diode
    • Semiconductor componant that allows current to flow in only one direction.
    • Used to convert AC current to DC.
    • Known as electical version of a valve (early diode).
    • Light-emitting diodes (LEDs) emit light when an electric current passes through them.
  5. Define:Fuse
    • Safety device that blows (melts) if the current flowing through exceeds a specific value.
    • Consist of a strip or coil of metal with a low melting temperature.
  6. Define:Ground
    Common voltage reference level defined by the container of electric circuit (chassis ground) or by the earth.
  7. Define:Inductor
    • Device that opposes changes in the flow of current, storing electrical energy in a magnetic field.
    • The letter L denotes inductance, which is measued in henries
    • Usually consist of a coil of wire, sometimes wrapped around a piece of iron (iron core) or an insulating shell (air core).
  8. Define:Resistor
    • Componant that opposes changes in the flow of current, transformimg electrical energy to heat.
    • The letter R denotes resistence, which is measued in ohms.
  9. Define:Resistor (Nonvariable) Color Code
    • Black:0
    • Brown:1
    • Red:2
    • Orange:3
    • Yellow:4
    • Green:5
    • Blue:6
    • Violet:7
    • Gray:8
    • White:9
  10. Define:Variable Resistor
    • Restrict the flow of electric current.
    • Types of variable resistors include
    • Rheostat:resistor with two contacts, usually used to control current. Example: Light brightness & motor speed.
    • Potentiometor:Resistor with three contacts, used to control voltage.
    • Preset variable resistors:device that operates with a small screwdriver or similar tool. Designed to be set with circuit & made and left without further adjustment.
  11. Define:Switch
    Device that interrupts or allows the flow of current in a curcuit.
  12. Name 6 types of switch & what they are used for?
    • Push switch:allows current to flow only when button is pressed, i/e/:doorbell.
    • Push-to-break switch:circuit is normally closed (device on), & the curcuit is open (device off) only when button id pressed.
    • On/off switch:allows current to flow only if it in a closed(on) position.
    • Two way switch:directs the flow of current to one of two routes, according to its position.
    • Dual on/off switch:often used to switch main electricity because it can isolate both the live & neutral connections.
    • Relay switch:electrically operated switch that may operate multiple switches at one time. Current flows through a coil sets up a megnetic field, which causes the lever(s) to move, effectively changing the relay switchs position.
  13. Define:Transistor
    • Amplify current.
    • Componant that controls the flow of current between the emitter (voltage output (e))& collector (voltage input (c)) by the voltage applied to the base (acts like a gate, voltage flow through the transistor (b)).
  14. Define:Amplifier
    Complex current (not a electronic component), used to magify power, current, or voltage.
  15. Define:Antenna
    Device designed to receive &/or transmit radio signals.
  16. Define:DC Power
    Power supply provides direct current which always flow in one direction.
  17. Define:AC Power
    Power supply provides alternating current which constantly changes direction at a specfic frequency.
  18. Define:Wires
    Used to pass current from one part of the component to another.
  19. Define:Transformer
    • Consist of two coils of wires linked by an iron core.
    • Used to step up (increase) & step down (decrese) AC voltages.
    • No electrical connection exists between the coils.
    • Energy is transferred between the coils by the magnetic field in the core.