User Guide

PAMS
Technical Documentation
HFU2 Handsfree Unit
Page 3
Original 11/97
Introduction
The HFU2 is a handsfree unit for DCT3 compatible handportable
phones. It provides rapid charging for the phone, a possibility to use HF
operation and connections to the datacard and handset unit. The HF
box can be connected directly to the Mobile holder MCC1 via the exter-
nal cable.
Technical Summary
The HFU2 has connections to car battery, car ignition sense, car radio
muting, antenna motor control, datacard, handset HSU1, external
speaker and microphone. The unit has a Systemconnector that pro-
vides an interface to the Mobile holder MCC1 via the external cable.
The unit consists of a rapid charger, HFmicrophone and speaker ampli-
fiers, interface to handset, datacard and phone, voltage regulators and
control circuit (microprocessor).
The HFU2 is always connected to the car battery. To save the car bat-
tery, HFU2 goes in to the sleep mode if the car is not running and/or the
phone is not connected.