source s charging and or recharging of the energy storage device 11 and other possible electrical activities that users require the switch 15 electrically coupled to the energy storage device 11 may be controlled by an external controlling unit not shown or an internal control unit such as the power supplying circuit 13 however the present invention is not limited to any particular power supplying circuit rather alternative circuit designs are possible which are known by people having ordinary skills in the art the power module 1 is powered by the power source s and is operated with the power supplying circuit 13 when the power of the power source s is inputted to the power module 1 the energy storage device 11 stores the power outputted from the power source s under control of the power supplying circuit 13 when the power source s is cut off the energy storage device 11 can be seen as an alternative and new power source the super capacitor also known as an electric double layer capacitor edlc is an element which generally has lower internal resistance and higher energy density than other kinds of known energy storage devices the super capacitor of the present invention including lithium ion capacitors also know as a u201c hybrid capacitor u201d has energy density greater than 136 w u00b7 h kg this kind of super capacitor based energy storage device 11 when recharged can restore more energy with a smaller current in a relative long time period and when discharged can release more energy with a greater current in a relative much shorter time period the brilliant charging and discharging performance is an important reason why the super capacitor is appropriate to be used as the energy storage device in the invention in other.