Electrical and Electronic Devices

TRANSFORMER

is a device that is used to change the magnitude of electric current and potential into higher and lower values.

TRANSFORMER

TRANSFORMER

applies the principle of mutual induction. It will operate only with a changing electric current (AC).

MUTUAL INDUCTION

Transformer applies the principle of ________

CHANGING ELECTRIC CURRENT (AC)

Transformer will operate only with a __________.

TRANSFORMER

Usually composed of wires wrapped around in an iron core and consists of primary and secondary coils

DIRECTLY PROPORTIONAL

The change in the voltage is _______ to the ratio of the number of turns (windings) in the secondary coil (Ns) to the number of turns in the primary coil (Np)

TRANSFORMER LAW

The change in the voltage is directly proportional to the ratio of the number of turns (windings) in the secondary coil (Ns) to the number of turns in the primary coil (Np)

OPPOSITE DIRECTION

The change in current across a transformer is in the _______ from the voltage change but in the same proportion.

STEP-UP TRANSFORMER

is transformer with a turns ratio greater than 1

STEP-UP TRANSFORMER

Increases the voltage but decreases the current

STEP-DOWN TRANSFORMER

a transformer with turns ratio less than 1.

STEP-DOWN TRANSFORMER

Decreases the voltage but increases the current.

STEP-UP TRANSFORMER

STEP-DOWN TRANSFORMER

Types of Transformer

AUTOTRANSFORMER

is made from a single primary winding wrapped around a laminated magnetic core, and operates on the principle of self-induction

SELF-INDUCTION

Autotransformer is made from a single primary winding wrapped around a laminated magnetic core, and operates on the principle of _______

TAPPED

This single winding is _________ at various points along its length to provide a percentage of the primary voltage supply across its secondary load

AUTOTRANSFORMER

This single winding is tapped at various points along its length to provide a percentage of the primary voltage supply across its secondary load

CAPACITOR

Is a device that stores electric charges producing a potential difference (static voltage) across its plates, much like a small rechargeable battery.

STORES ELECTRIC CHARGES

Capacitor is a device that _________

CAPACITOR

CAPACITOR

consists of two or more parallel conductive (metal) plates that are electrically separated either by air or insulating material

PARALLEL CONDUCTIVE PLATES

Capacitor consists of two or more __________ that are electrically separated either by air or insulating material.

AIR

INSULATING MATERIAL

Capacitor consists of two or more parallel conductive (metal) plates that are electrically separated either by _____ or ________

DIELECTRIC

The insulating material between plates is called ______

RECTIFIER

is an electrical device which converts an alternating current (AC) into a direct current (DC) by allowing the current to flow through it in only one direction.

RECTIFICATION

is the process of converting AC to DC.

PULSATING

SMOOTH

The output DC is a______ DC and not a _______ DC.

RECTIFIER

SMOOTH DC

PULSATING DC

RECTIFIER

Uses diodes that allow one-way flow of electrons

DIODES

ONE-WAY

Rectifier uses ______ that allow _____ flow of electrons

HALF-WAVE RECTIFICATION

FULL-WAVE RECTIFICATION

Types of Rectification

HALF-WAVE RECTIFICATION

Uses one or two diodes that allow only half of the AC cycle to pass, while the other half is blocked

FULL-WAVE RECTIFICATION

Uses several diodes that allow both the positive and negative cycle of the AC wave to pass.

RHEOSTAT

or variable resistor is an electrical instrument that is used to control current by varying the resistance.

RHEOSTAT

are able to vary the resistance in a circuit without interruption.

RHEOSTAT

CIRCUIT BREAKER

ELECTRICAL GROUNDING

Protective Devices

CIRCUIT BREAKER

is a device that opens a circuit as soon as current climbs to unsafe levels.

SWITCH

ELECTROMAGNET

The basic circuit breaker consists of a simple ______, connected to _______.

MAGNETIZES

The electricity _______ the electromagnet. When the current jumps to unsafe levels, the electromagnet is strong enough to severe this contact point and shuts off the electricity.

ELECTRICAL GROUNDING

is a backup pathway that provides an alternate route for electrical current to flow back into ground in the case of a problem in the wiring system

BACKUP PATHWAY

The grounding system is a _________ that provides an alternate route for electrical current to flow back into ground in the case of a problem in the wiring system