A low voltage DC power supply for fluorescent lamps with battery protection unit

A wide range of electronic equipment uses Uninterruptible Power System units in order to continue operating in case there is loss of power supply. Due to their battery, the Uninterruptible Power Systems guarantee that the electronic device will operate autonomously for a certain period of time. In this work, an automatic charger/regulator circuit for a lead- acid battery is developed. The charger/regulator circuit consists of the battery charger, the electronic circuit that supplies the load with DC voltage and the circuit that protects the battery from deep discharge. The specifications of the aforementioned circuit are appropriate for the DC voltage supply of a pharos´s lighting device (fluorescent lamps). The charger/regulator circuit charges the battery via the 230V AC mains voltage in order to supply the lighting device (load) with 12V DC. In case the mains voltage is interrupted, the battery continues to supply the load with 12V DC. The battery stops to supply the load when its voltage becomes less than 9.5V, in order to avoid damage due to deep discharge.