Трансформатор LUNDAHL LL7401. Инструкция на английском языке

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Audio Output Transformer
LL7401
LL7401 is an audio output transformer for balanced drive.
In LL7401 a five section winding structure is used. This results in a very low leakage inductance without  high
capacitive coupling  and low isolation voltage, which are drawbacks of the bifilar winding technique.
Turns ratio:                                                    1 + 1: 1 + 1
Dims (Length x Width x Height above PCB (mm)):                  47 x 34 x 17
Pin layout (viewed from component side) and winding schematics:
1                7
6                  12
2
5                  11
3                8
4                 10
LL7401
3    (Top view)                  6                12
2                   8
5
1                   7
4                11
Can+Core   10
Spacing between pins:                                           5.08 mm  (0.2")
Spacing between rows of pins:                                   35.56 mm  (1.4")
Weight:                                                         92 g
Rec. PCB hole diameter:                                  1.5 mm
Static resistance of each primary:                              9 W
Static resistance of each secondary:                            9 W
Leakage inductance of secondaries (sec. in series):      50 µH
No-load impedance:                                              >700 W @ 50 Hz, +20 dBU
Optimum source impedance:                                       Minus 9 W (See application  below)
Balance of output (according to IRT, source < 10 W , Load 600 W):  > 60 dB
Note!   Performance figures below are obtained using mixed feedback drive circuits. (See application
example).Otherwise use lowest possible source impedance.
Distortion (connection as application example below, load 600 W)  0.05 %  @ +22 dBU, 50 Hz
Frequency response (@ 10 dBU, connections as below , load 600 W): 20 Hz -- 80 kHz +/- 0.3 dB
Voltage loss across transformer (at midband with 600 W load):   0 dB
Isolation between primary and secondary windings / between
windings and core:                                              4 kV / 2 kV
Application example with mixed feedback: (NOTE! This application is covered by a German patent
DE 29 01 567 with application day 13.1.79, valid as far as we know in Germany only.)
Cin  Rin
Rf
_                                             LL7401
+
NE5534                                      7         1            _
+                                            8         3
_
6
11        4            +
10k      R    10k                                  12        5
10   2
10k
_
Gain = Rf / Rin
NE5534                              Optimum R <= Rp • (Rin/Rf)
+
where Rp is Cu resistance of prim.
Select R for best THD at LF
R980626