Inductors and transformers

An inductor resists changes in current and stores energy in a magnetic field. A transformer transfers AC energy through separate windings on the same core; the turns ratio sets the voltage. DC resistance, saturation and heating limits matter. The Lab uses low voltage only; no real connection is made to a 230 V primary.

2 types2 groupsSymbol IEC

Single winding

1
100 µH axial ferrite inductor
Inductor / coil (100 µH)Slowing down current changes, storing energy in a magnetic field and building filters
Inductance
100 µH
Tolerance
±10% · ±20%
DC resistance
≈0.3–1 Ω

Isolated transfer

1
Lab: EI30, 24 V / 12 V test transformer; real example: EI30, 230 V / 12 V, 1.5–2 VA isolation transformer
Transformer (24 V / 12 V, EI30)Converting AC voltage and transferring energy through isolated windings
Primary (Lab)
24 V RMS AC
Secondary (Lab)
12 V RMS AC
Turns ratio (Lab)
2:1
Which one should I choose?
1
When you need to slow down current changes or build an LC filter
Inductor / coil (100 µH)
Choose DCR, Isat and heating current together with the inductance.
2
When you need to convert AC voltage by the turns ratio
Transformer (24 V / 12 V, EI30)
Separate windings provide isolation; in a real experiment use a closed low-voltage source.
Compare2 types · 4 features
TypeBase valueCurrent limitIsolationTypical use
Inductor / coil (100 µH)100 µH, DCR ≈0.3–1 ΩIsat and Irms, depends on the seriesSingle winding, no galvanic isolationLC filter, energy storage
Transformer (24 V / 12 V, EI30)24 / 12 V AC, 2:1 (Lab)Primary overload above 150 mA (Lab)Separate primary and secondaryIsolated low-voltage AC

Typical values; they vary by manufacturer and series. Lab uses only low voltage.