Self-oscillating inverter power supply having continuously variable output frequency, and constant current driver power supply

Provided is a self-oscillating inverter power supply having continuously variable output frequency or output power. The power supply is provided with an inverter switching circuit (101), at least two magnetic current transformers (102 and 106), a load circuit (103), and a control circuit (105). Each magnetic current transformer is provided with primary windings (102a and 106a), secondary windings (102b, 102c, 106b, and 106c), or a control winding (102d). The primary windings (102a and 106a) respectively are connected to an output and a load of a power tube. The secondary windings (102b, 102c, 106b, and 106c) are connected to the inverter switching circuit (101) to drive the power tube thereof. An output of the control circuit (105) is parallel-connected to any one of the windings of the magnetic current transformers to change an output impedance of the control circuit (105), thereby allowing changes in the self-oscillation frequency. The power supply provides reliable output frequency and variable output power and also is applicable in a constant current driver power supply or a self-oscillating electronic ballast of a gas-discharge lamp.