System overview 
                         
                        Solar gadgets produce their own power through the  sun light (in some cases through dynamo too) for powering their loads.  Due to limited power required and to make the  unit more mobile, solar panels are mounted on the gadgets itself.  
                         
                        
                        Functions of different components 
                      Solar panel: Converts  sun light into electric current. Usually, solar panels in gadgets range from 0.2 Watts to 2 Watts.  It is very difficult for a common man to know  what the panel size is of the gadget by looking at the panel.  Most of the gadgets are rated in terms of  daily load power in hours.  This is the  best way to rate the gadgets. 
                      Batteries: Usually,  NiCD or NiMH batteries are used in gadgets.   These batteries are lighter in weight and are more stable in terms of  voltage.  Also, these batteries are  generally commonly available and therefore can be easily replaced.  
                             
                        Note: Solar gadgets do not need controllers as the size of  the solar panel is very small.  Usually,  if the panel size exceeds 10W, then it is beneficial to connect a controller. 
                      Reliability: Due to minimalist design of the gadgets using only the  components of long life, gadgets usually are quite reliable.  In case of failures, then just by replacing  batteries, you can usually revive the gadget back into working condition. 
                      Viability: Solar panel takes up a large share of the system cost.  And, it is the solar panel which makes the  electricity.  All the gadgets are very  competitively priced and are always good to have for emergency needs.  
                             
                        *Components are of energy  saver types.  Apex has a ready stock of  most of these components. 
                         
                         |