摘要 |
<p>The adapter includes an universal casing and a support at a specific distance, including a cradle to receive the telephone. The casing includes a universal output audio circuit (56) to deliver the output signal on a number of output terminals (HP+,HP-,L1+,L+) selectively connected to the external units for restitution of sound (30,34) along different configurations of possible connections. The circuit has a symmetric configuration with a main amplifier (60) with differential outputs and two secondary amplifiers (62,62') with differential inputs and non-differential outputs. The inputs and outputs of the main and secondary amplifiers are coupled between themselves via a potential referencing circuit (64,66,68, Vref) connected to the input terminal (L1-; L2-) which is susceptible, or not, to be connected to an external mass.</p> |