Nokia 2220 Servicehandbuch

RH-42

System Module

CCS Technical Documentation

Page 18

 Nokia Corporation          Confidential

Issue 2 09/2003

of magnetic material and it is located in a magnetic field created by a permanent mag-
net. The winding is not attached to the diaphragm, as is the case with the speaker. The 
winding is located in the magnetic circuit so that it can alter the magnetic field of the 
permanent magnet, thus changing the magnetic force affecting the diaphragm. The 
buzzer's useful frequency range is approximately from 2 kHz to 5 kHz.

The BMC-3 battery (Ni-MH 900mAh) is be used in the RH-42 transceiver by default. It is 
also possible to use the BLC-2 (Li-ion 950mA) battery.

The battery block contains NTC and BSI resistors for temperature measurement and bat-
tery identification. The BSI fixed resistor value indicates the chemistry and default 
capacity of a battery. The NTC-resistor measures the battery temperature. Temperature 
and capacity information is needed for charge control. These resistors are connected to 
BSI and BTEMP pins of the battery connector. The phone has pull-up resistors for these 
lines so that they can be read by A/D inputs in the phone (see the figure below). Serial 
resistors in the BSI and BTEMP lines are for ESD protection. Both lines also have spark 
caps to prevent ESD. There is also a varistor in the BTEMP line for ESD protection.

The batteries have a specific red line, which indicates if the battery has been subjected to 
excess humidity (red line spreads). The batteries are delivered in the protection mode, 

which gives longer storage time. The voltage seen in the outer terminals is zero (or float-
ing), and the battery is activated by connecting the charger. The battery has internal pro-
tection for overvoltage and overcurrent.

 

UEM 

VANA  VBAT

 

 

VBATT 

GND 

VFLASH1