Low power photovoltaic system with lead acid battery for 5V regulated voltage – electronic circuits

The present work concern the study of monocrystalline silicon based photovoltaic (PV) module as input unit for alone low power PV system. The PV module is associated with simple controlling circuit for the lead acid battery as storage unit and the voltage regulator 5V DC as output unit of the PV system. Such PV system may be used as a power supplier for some electronics devices; portable phones and small computers, luminous traffic sign and displays, programmable components and microcontrollers, timers, embedded systems (GSM, PIC, FPGA cards…). Indeed, the aim of our investigation resides in the conception and realization of reliable low cost portable photovoltaic system. A number of measurements have been performed, and the reliability of the PV system has been investigated. At first, an indoor study of the photovoltaic module has been investigated; the measurements showed that the short circuit current increases linearly with the light radiation, in particular at low light intensities. In addition, in order to regulate a voltage value of 4 to 5V DC when the system is connected to the output load resistance, the resistance value should be higher than 100. Thus, the input voltage must be at least of 1 to 3V larger than the regulated voltage of 4 to 5V DC.