The AC power supply through a resistance capacitance step-down unit after this, signal display and a bridge rectifier, it is used to charge the battery, the switch, when the switch is open, closed ahead, a group of light emitting diode connected to the work below, this is due to the reverse cutting diode D5 check, above a group is not working; when the switch is closed due to backward, forward by D5, the two groups of light emitting diodes are given the same power and work. This is the flashlight can have two different light. The main role of D5 is to use its reverse cut-off characteristics to limit part of the circuit work, to adjust the role of light source.
The following nutrients are called power circuits. The above part is called the working circuit. One of the detailed principles, is the most basic concept, in any one on the basis of electronic or application of information have, interested, just look for a can see.