Solar energy powered street light fitting - has self-programming electronic control effective according to battery charge and/or received radiation by day

摘要

A photovoltaic cell array (10) charges a secondary battery (12) via a diode (11) in a regulatory circuit including two semiconductor switches (13,24) wired to a microprocessor (15). The irradiation of the array and the voltage of the battery are monitored by resistive voltage dividers (17,18;20,21). The microprocessor is programmed to compare the brightness with a twilight criterion, to switch the lamp(s) (14) on and off, and to monitor the battery charge with temp. compensation by NTC resistor (23). USE/ADVANTAGE - For street lighting, without need for maintenance but with automatic matching to varying ambient light.