Patent ID: 8884536

Claim:
A lighting power source comprising: a rectification circuit configured to rectify an input AC voltage; a smoothing capacitor; a waveform shaping circuit connected between the rectification circuit and the smoothing capacitor, configured to perform a switching operation to repeat an ON state and an OFF state when voltage output from the rectification circuit is relatively high, and configured to continue to be in the ON state to allow a current to flow to the rectification circuit when the voltage output from the rectification circuit is relatively low; and a DC-DC converter configured to convert a voltage charged in the smoothing capacitor, the waveform shaping circuit including: a choke coil; a switching element configured to allow a current to flow through the rectification circuit via the choke coil, the switching element being a normally-on type element, the switching element being controlled to the ON state or the OFF state on the basis of a current flowing through the choke coil; and a drive winding magnetically coupled to the choke coil, a voltage induced in the drive winding being supplied to a control terminal of the switching element, and the waveform shaping circuit being of a self-exciting type and being configured to continue the switching operation or the ON state.