Lundahl Isolation transformer, LL1532

General Purpose Audio Transformers LL1532

LL1532 and LL1593 are small size medium impedance transformers suitable for splitting and other general purpose applications.

LL1532 consists of two coils each with one primary and one secondary winding separated by an electrostatic (Faraday) shield. The two secondary windings are internally connected in series. The core is a high permeability mu-metal core. The LL1532 is magnetically shielded by a mu-metal housing.

LL1593 is a low-cost version of the LL1532, with the same winding structure but without Faraday shields and mu-metal housing.

The LL1532 and LL1592 can be used with primaries in series for 1:1 or in parallel for 1:2 turns ratio.

Turns ratio: 1 + 1 : 2
Dims (Length x Width x Height above PCB (mm)): 28 x 17 x 15 / 28 x 17 x 14

Spacing between pins: 3.81 mm (0.15")
Spacing between rows of pins: 20.32 mm (0.8")
Weight: 25 g / 19 g
Rec. PCB hole diameter: 1.5 mm

Static resistance of each primary: 70W
Static resistance of each secondary: 180W
Distortion (primaries connected in series, source impedance 600W):
+ 6 dBU primary level, 50 Hz: 0.2 %
+ 12 dBU primary level, 50 Hz: 1 %

Self resonance point: ~ 200 kHz
Frequency response (source 600W , load 10kW): 10 Hz - 60 kHz +/- 0.3 dB
Optimum termination for best square-wave response (source imp. 600W ): 2 kW in series with 1.6 nF

Isolation between windings/ between windings and shield: 3 kV / 1.5 kV