Use TWH8751 to make power outage emergency lighting

The power outage emergency lighting circuit made with IWH8751 is shown in Figure 3-52. The circuit consists of an automatic charging circuit and
  an inverter power supply composed of the TWH8751 power switch integrated circuit.
    Switch SB should be in a closed state at ordinary times, and VD1-VD7, CI, C2, RI, R2 and LED form the
  automatic After the circuit is powered on, due to the current limiting effect of the capacitor Cl, G will be charged with a constant current of about 60mA. The LED will light up to indicate when
  charging . After G is fully charged, due to the high voltage at both ends of G, the voltage difference between the two ends of the LED will becomes smaller, when
  it drops below 1.6V, the LED will turn off and no longer charge G, thus effectively preventing the battery from overcharging. The circuit
  setting VD5, VD6 and the voltage stabilizing diode VD7 are connected in series. The purpose is to raise the potential of the left end of the LED so that when the battery G is low in
  power the LED can illuminate normally and charge G. ,
    the power switch integrated circuit IWH8751, the photoresistor RG, the transformer T, etc. form a light-controlled inverter power supply.
  When the indoor light is strong, the RG has a low resistance, causing the 2-pin of the integrated block to be at a high level (large stem 1.5V 】, the oscillator stops vibrating, that is, the
  inverter power supply does not work, and the emergency fluorescent lamp H does not light up. Once the power fails and the indoor light becomes dark, RO has a high resistance, causing
  pin 2 of the integrated block to become low level, and the oscillator starts to vibrate immediately. The inverter power supply outputs high voltage to make the 8W fluorescent tube H light up, thus
realizing automatic lighting during power outage.