Push to ON and OFF latching Circuit

    Here we can make load ON and OFF using push switches or in a low voltages. using relay in Q1s collector we can control any load with isolation. here me added 5.1V zener to avoid leakage currents that will make the circuit ON when power is ON. current flows through the circuit only when we made ON. so standby current is negligible.

Simple LED Emergency Light

This is simple to make and low cost emergency light. also it gives better backup more than 3 Hour.
low cost and simplicity comes by replacing the battery charger circuit with a any mobile charger, here the connector CN1 must be socket of any mobile charger here me used nokia's charger pin convertor.
  
   The output voltage of most of mobiles will be in 5-7 Volts thus it is suitable for 4.8V batteries. LED D5 acts as charging indicator. while connecting LEDs in parallel all must be same type (same batch).