Lundahl Filament current choke, LL2733

Filament Current Choke LL2733

The LL2733 is a 2 coil choke for tube/valve filament current filtering. The coil is wound using our standard high internal isolation technique with isolation foil between each copper layer. The core is an audio C-core of our own production.

Weight: 1.35 kg
Static resistance of each winding: 1.7 ?
Max current through each winding (10W heat dissipation): 1.7 A
Isolation between windings / between windings and core: 4 kV / 2 kV

Coils in series
Approx. Inductance: 0.4 H
Recommended DC current (1.25 T): 1.7 A
Saturating current (2.0 T): 2.7 A
Max. ripple voltage at rec. DC current (Ripple voltage is approx. 0.42 x input voltage): 120 V rms / 100 Hz

Coils in parallel
Approx. Inductance: 0.01 H
Recommended DC current (1.25 T): 3,4 A
Saturating current (2.0 T): 5.4 A
Max. ripple voltage at rec. DC current (Ripple voltage is approx. 0.42 x input voltage): 60 V rms / 100 Hz

Note! The LL2733 can also be used in choke input power supplies.