Private Communication Systems
Mobile Phones
The 2.8V power supply of TCXO, Receiver and Modulator is derived directly from the
battery voltage by a separate linear regulator.
During testing ist is advisable to use the service adapter, connected to a power supply
deli4V, max 3A. Make sure that you connect the service adapter with the right
polarity, the red plug to +4V and the blue plug to ground.
CAUTION!
If you use a voltage higher than +7V, or with wrong polarity, the phone can be destroyed!
4.4Limits of Voltage and Current
a) Battery Voltage:
If the battery voltages rises above 6.2 Volts, the phone will switch off and it cannot be
switched on again before the voltage is lower than 6.2 Volts.
If the battery voltage rises above 7 Volts the phone can be destroyed.
b) Charging Current:
The charging current must not rise above 1 A or the phone (fuse) will be inoperable.
Be careful with foreign accessories or chargers!
Make sure that the charging current is limited to a value below 1A!
Service Manual SL10
V1.1
PN MP ST
R. Fleuren
Sm_sl10_lvl2_v11.doc
Page
18
of 23
05/98
