Dual output electronic ballast circuit diagram

IC 1, TR1, TR2, L1, etc. form a switching power supply with an output of 80V . Part of IC1 forms a 65kHz square wave oscillator that drives N-channel MOSFET-TR2 after buffering, so that TR2 works in a switching state. During the 8us period when TR2 is turned on each time, the current flowing through L1 can reach a maximum of 150mA. At this time, D3 is turned off, and L1 stores energy in the form of a magnetic field. When TR2 is turned off, the induced current generated by L1 in the same direction charges C3 through D3, causing the voltage of C3 to increase. When its voltage rises to 80V, Zener diodes D1 and D2 conduct. Then TR1 is turned on, setting pin 13 of IC1 to low level, the oscillator stops and the output voltage is limited to 80V. The six inverters of IC 2 and the surrounding components form a pulse generator, so that the 80V generated by the switching power supply The voltage is output to the external electrode in the selected pulse mode.