Inverter circuit three

It is a self-excited transistor inverter circuit . It can convert 4.5~6V DC power into 220V AC power for
use by 8~40W fluorescent lamps. According to the component parameters shown in Figure 2-121, it can be used for 8W fluorescent lamps.
    The function of the diodes VDi and VD2 is to prevent the junction breakdown of the transistors VTi and VT2 from being damaged. Because at
the moment when the lamp is started, the triode changes from conduction to shutdown, the winding connected in series to
the base circuit of the triode will generate a relatively high back pressure between the be
junctions.
    The advantage of this circuit is that the load is directly connected in parallel to the oscillation circuit
, so the circuit will stop oscillating when the output load is too heavy, thus protecting
the transistor from damage. The disadvantage is that the efficiency is low, and the output voltage and
oscillation frequency are greatly affected by the power supply.