Lundahl Isolation transformer, LL1570XL

Transformers for splitting LL1570

The LL1570 is designed for splitting signals in application where large ground differences may appear, but is also very useful as a general purpose audio transformer. By careful design, the capacative coupling between the different part of the transformer is kept to a minimum. The three-section winding structure which is necessary for decoupling also results in a very high bandwidth. The transformer is built up from two coils, each with primary and secondary windings separated by electrostatic shields, and a high permeability mu-metal core. The two coil structure in combination with the mu-metal can results in high immunity to external magnetic fields.

In the LL1570XL, the core is about 45% larger than in the LL1570, resulting in a larger level capability.

Turns ratio: 1 + 1 : 1 + 1

Spacing between pins: 5.08 mm (0.2")
Spacing between rows of pins: 27.94 mm (1.1")
Offset of earth pin from adjacent row: 2.54 mm (0.1")
Recommended PCB hole diameter: 1.5 mm