User Guide

NHB–3
Technical Documentation
PAMS
Desktop Charger CHH–2
Original 26/97 Page 5
Charging Indication
Charge is indicated with two dual–colors led‘s, one for the phone and one for
the extra battery pack. The liquid–crystal display of the phone also contains a
three–bar battery display.
Led‘s are dim when there is no phone or extra battery connected.
Right led for handportable:
Red phone led indicates a fast charge mode of the phone battery.
Green phone led indicates a tricle (maintenance) charge mode of the phone
battery; with steady lcd battery display it means that the battery is full. If the led
is green but the battery display is scrolling, charging is disabled due to battery
temperature (less than +5 or more than +45 Centigrade).
Left led for spare battery:
Red spare battery led indicates that the battery is not full; either there is a fast
charge mode active or charging is disabled due to a battery temperature or to
fast charge mode of the phone.
Green spare battery led indicates that the battery is full.
Flashing red spare battery led indicates that a discharge cycle is activated.
Technical Specifications
Charge States and Charge Control
Charge current for the phone is supplied through a series switch transistor in
the phone. When this transistor is on the charger is supplying a constant cur-
rent to the phone. This is the rapid charge mode.
When the transistor is off no current is supplied to the phone and the charger is
in the constant voltage mode.
Having been charged up in the rapid charge mode, the battery is kept in full
charge using pulsed charging, i.e. switching power alternately on and off at a
variable duty cycle and a frequency of a few Hz.
The desktop charger is also provided with control logic for spare battery charg-
ing, which is allowed when no phone is connected or when the phone is in the
pulsed charge mode.