Inductors/Transformers

Henry (H)

Measurement of inductance

What effect do Transformers on voltage/current

Changes them in order to match output voltage/current

Main purpose of inductors

Concentrates a magnetic field

Secondary and Primary markings

ES - Secondary Voltage EP - Primary Voltage NP - Number of turns in primary NS - Number of turns in secondary

Primary and secondary ratio

Ep/Es = Np/Ns

Variable Core Inductor

Variable varies in large and small values

How much voltage is induced into the coil when current is constant?

no voltage is induced into the coil

Inductance (L) Definition

the ability of a conductor to induce voltage when cut by magnetic flux.

if ratio = 1:1 the voltage will be....

the same for primary and secondary

1. If (Np>Ns) and 2. If (Np<Ns) then....

1. If (Np>Ns) then voltage drops down 2. if (Np<Ns) then voltage steps up

What does an inductor to the circuit current when, 1. current flow increases, 2. current flow decreases?

1. When current increases, the inductor decreases circuit current 2. When current decreases, the inductor increases circuit current

Factors determining induction (# of turns, winding closeness, cross section size, permeability)

1. increase in turns = increase inductance 2. the closer the windings = increase inductance 3. bigger cross section = increase induction 4. greater permeability = increase induction (iron core) decrease induction (air core)

What is Input to a transformer?

Applied to a transformer is applied to one coil which is called the primary

What is inductance determined by?

By the inductors ability to concentrate a magnetic field.

Finding primary current in a transformer current

Ip = (Is x Es) / Ep

Finding secondary current in a transformer current

Is = Es/Rl

Air Core inductor

Keeps circuit current constant

Iron Core Inductor

Larger values = larger magnetic field

Turn Ratio =

Np (# of primary turns) ---------------------------- = Np : Ns Ns (# of secondary turns)

Short

R = 0 I = Max V = 0

Open

R =max I = 0 V = Applied voltage

Which voltage should you always find first?

Secondary voltage

Output

Taken from the other coil which is called the secondary

What is the Principle of mutual inductance

The ability of the magnetic field of one coil to induce voltage in a second coil.

Phase inversion

When a transformers reverses the phase of the applied AC voltage or sine wave.

Construction of an inductor

Winding wire around a core

Transformers definition

isolates one circuit from another, preventing the circuits from affecting each other.