Double tube emergency fluorescent light circuit 4

Rechargeable emergency fluorescent light circuit for Hitachi. It uses a switch circuit composed of a multi -contact transfer switch SA and two transistors VT3 and VT4 to complete the working mode selection.
The four working modes (there is no 220V mains power at this time. VTi and VT3 are both cut off) are as follows. ① When SA is set to 1, 6V voltage is added to the oscillation circuit through contacts 1 and 4, windings
    W3 and W2 , and the fluorescent lamps Gi and Gz light up.     ②When SA is set to 2, contacts Z and 4 are connected, VT4 is conducted, and the light EL is on.     ③When SA is set to 4, Gi, G2 and EL will not light up.     ④When SA is set to 6, Gi, Gz and EL will all light up.