This series consists of three models of a power supply-charger which, in the presence of mains voltage, supplies regulated voltage, while at the same time charging the battery in a controlled way. The range is ideal for charging lead-acid batteries of 12V, 24V, and 48V with capacities of up to 48Ah, 24Ah, and 12Ah respectively.
The device comprises a switched-mode power supply and a charging current limiter circuit, which provides for constant voltage battery charging with limited charging current. It also incorporates an alarm circuitry which acts independently, when mains or power supply failure or a low battery condition occurs. The alarm outputs are the switched, potential-free contacts of relays.
When the mains supply is on, the output current is obtained directly from the power supply. The maximum battery charging current can be selected by the user by means of DIL switch (see figure). The maximum battery charging current will be equal to the set current or equal to the rated current less the output current; the floating voltage will be equal to the output voltage.
The system allows the temporary supply of an output current higher than the rated current. The average of this additional current, which is obtained from the battery, should not exceed the charging current as, otherwise, the battery would finally discharge.
If the power supply has no output, due to a mains voltage outage or to a failure in the power supply, the supply failure alarm will be triggered.
Operation without mains supply
When there is no mains supply, the battery comes, uninterruptedly, into operation and the output current is obtained from the battery. The output voltage will then depend on the battery discharge curve.
If the battery runs flat, the low battery alarm will be triggered. It will be disconnected from the output by way of a relay to prevent a deep discharge of the battery. When the mains supply returns, the UPS may take several minutes to supply the established battery charging current. During this time, the battery is charged with a small current until the low battery status is overcome. At that moment, the low battery alarm is reset, the relay closes, and the battery starts to charge normally.