Ericsson 344A3072P8, Maintenance Manual, Page: 5 / 26

DESCRIPTION
The Universal Multi-unit Charger is designed to charge
Ericsson personal radio battery packs. The charger is capa-
ble of charging up to six battery packs at one time and is
available as a Standard or Rapid Charger.
The use of interchangeable battery sleeves permits
charging different battery pack families at the same time (i.e.
two M-RK and four M-PD sleeve inserts in the same
charger). The sleeves allow charging a battery pack alone or
attached to a radio and can be easily installed or removed
from the charger.
Each sleeve has spring loaded electrical charging con-
tacts and contains circuitry unique to charging a particular
family of battery packs. The sleeve is designed to plug easily
into the charger base using guides in the base for self align-
ment.
Battery Pack sleeves are available for most Ericsson
personal radios including M-PA, M-PD, PCS etc. The fol-
lowing listing identifies the sleeve required for each radio.
RADIO TYPE SLEEVE NUMBER
M-PA, M-PD, 344A3072P5
MTL, PLS, & TPX
PCS 344A3072P6
M-RK 344A3072P7
STANDARD CHARGER
The Standard Multi-unit Charger may be powered by
either a 120 Vac or 230 Vac 50/60 Hz power source. Ensure
the charger’s voltage selection switch is set to the proper
voltage before applying power. Switching on the Charger’s
ON/OFF power switch applies input power to the built-in
power supply board.
The power supply board (PS-9) rectifies the input power
and produces a stable DC voltage to the A1 printed circuit
board (PCB). The power supply’s output is 15 Vdc and up to
1.14 amps which is supplied to the six A1 charger PCBs.
A constant current is developed through the use of
various series resistance combinations. In connection with
the sleeve circuitry, the proper selection of series resistors
controls the current needed for the particular battery pack
being charged. This also includes series resistors selected by
the long or short battery pack microswitch. A portion of the
current flows through the CHARGE LED indicating the
battery pack is connected and is being charged.
RAPID CHARGER
The Rapid Multi-unit Charger may also be powered by
either a 120 Vac or 230 Vac 50/60 Hz power source. Ensure
the charger’s voltage selection switch is set to the proper
voltage before applying power. Switching on the Charger’s
ON/OFF power switch applies input power to the built-in
power supply board.
The power supply board (PS-8) rectifies the input power
to produce a stable DC voltage for the constant current
regulator PCBs (CC-8). The power supply’s output is 13 Vdc
at 10 amps which is supplied to the three constant current
regulators.
Each constant current regulator provides a constant cur-
rent of 1.9 or 1.3 amps for two battery packs via the charge
control PCB (CHG-1). This constant current is selected by a
control signal from the charge control board.
The Rapid Charger is microprocessor controlled and
uses switching current regulators to regulate the charge cur-
rent. Battery voltage and temperature are monitored by the
microprocessor which controls the CHARGE and READY
LEDs and the charge enable transistor.
Recharging any battery pack or batteries other than
the ones your equipment was designed to charge
may result in damage to equipment, leakage, or
explosion.
CAUTION
LBI-38708
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