Charger 6 / Charger 12
rel. 1.3c -E- english, page
12
of
22
When the mains present, the power supply maintains the external battery banks in their fully charged
state. Power supply’s operation is controlled by the microprocessor controller, which independently
supervises the batteries, maintaining the floating mode voltage in them (depending on ambient
temperature, if the external temperature sensor has been connected). This sensor should be located
near the battery. If the sensor is absent, the controller maintains voltage corresponding to the
ambient temperature of 25
°
C.
In case of power failure, the loads connected to the power supply are supplied directly from the
battery bank – this is the battery mode. As the mains power supply returns, the battery bank charging
current is above the set point, the power supply proceeds to the bulk charging mode.
This mode is characterized by charging using limited current at the increased voltage. The end of the
bulk charging at a fully operational battery bank is defined by a significant drop of charging current
after the preset charging voltage has been reached, after which the power supply decreases the
voltage to the level of floating mode voltage, continuing charging at this voltage. If the battery bank is
faulty, the bulk charging is interrupted in the fault mode after the maximum, preset charging time has
been exceeded or when the permissible ambient temperature of the battery bank is exceeded.
The circuit of the CHARGER 6 or CHARGER 12 power supply is equipped with a Low Voltage
Disconnector (LVD) – an internal switch of deep discharge implemented in the relays in their output
circuits (one relay in each circuit for powering one amplifier and one at each double outputs for
powering the VAS controller). They disconnect the outputs from the battery banks when the battery
reaches the minimum permissible discharge level, thus preventing it from further discharging and
preventing it from being destroyed.
The second RB disconnector – battery disconnector disconnects the additional outputs when
detecting short circuit in the battery circuit supplying power to the additional outputs from the
rectifier.
Measurement of battery circuit resistance is an additional function of the controller. The resistance
measurement takes place only in the floating mode operation. Detection of battery circuit resistance
increase caused by an increase in internal resistance of the battery or by an increase of battery
connection resistance, causes the indication for reaching high battery circuit resistance to be sent. If
the battery bank gets disconnected, the controller detects a significant increase of battery circuit
resistance and indicates a device configuration error.
The power supply is equipped with a function of voltage equalisation between batteries of each
battery string. Voltage equalisation takes place as a result of loading the half of batteries which exhibit
higher voltage, with a small current, of 100mA. This function is called for if the voltage difference
exceeds 0.1V.
The use of voltage equalising circuit requires an additional connection to be introduced between the
M terminal of a given battery string and the median point of the battery itself. This system is resistant
to an incorrect connection of this connector (to an inappropriate terminal of any battery), indicating a
fault in such situations. The lack of this connection is automatically detected which results in switching
off the voltage equalising system.
The circuit of the CHARGER 6 or CHARGER 12 power supply is continuously controlling the state of
outputs fuses on each output for amplifier and controllers. A fault to any of them results in a fault
signal being generated (the signalling lights on the front panel of the power supply unit are switched
on and the remote signalling to be put out), and in addition, switching on a yellow LED diode located
near the faulted outputs.
When the power supply unit is switched on, state of load at the outputs designed for VAS amplifiers is
checked. Lack of current consumption from these outputs is required. If any of the amplifiers has e.g.
its own power supply switched off (or faulty), which results in an attempt of switching it on using
output voltage of the power supply unit, such the state shall be detected and the relay present at this
