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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.
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Define:Cell
- Supplies electrical current.
- Some call it the battery, but techniquely a battery has more then 1 cell.
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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).
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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.
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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.
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Define:Ground
Common voltage reference level defined by the container of electric circuit (chassis ground) or by the earth.
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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).
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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.
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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
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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.
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Define:Switch
Device that interrupts or allows the flow of current in a curcuit.
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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.
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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)).
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Define:Amplifier
Complex current (not a electronic component), used to magify power, current, or voltage.
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Define:Antenna
Device designed to receive &/or transmit radio signals.
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Define:DC Power
Power supply provides direct current which always flow in one direction.
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Define:AC Power
Power supply provides alternating current which constantly changes direction at a specfic frequency.
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Define:Wires
Used to pass current from one part of the component to another.
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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.
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