Led driver circuit

An LED driver circuit comprising:

• a diode bridge rectifier circuit that full-wave rectifies the alternating current to output the rectified output voltage;
• a first LED group, in which a plurality of first LEDs are connected in series and which is connected to the diode bridge rectifier circuit in parallel;
• a second LED group, in which a plurality of second LEDs are connected in series and which is connected to the diode bridge rectifier circuit in parallel;
• a third LED group, in which a plurality of the second LEDs are connected in series and which is connected to the second LED group in series;
• a first phosphor-containing resin region that covers the first LED group, and converts a wavelength of light emitted from the first LED group to emit the light having a first color temperature;
• a second phosphor-containing resin region that covers the second LED group and the third LED group, and converts a wavelength of light emitted from the second LED group and the third LED group to emit the light having a second color temperature;
• and
• a control unit that switches from a condition that only the first LED group is turning-on to a condition that only the second LED group is turning-on, and further, from the condition that only the second LED group is turning-on to a condition that the second LED group and the third LED group are turning-on in response to an increase in the rectified output voltage, wherein
• the number of the first LEDs included in the first LED group is smaller than the number of the second LEDs included in the second LED group,
• the control unit includes a bypass pathway arranged between the second LED group and the third LED group, and
• the control unit switches from the condition that only the first LED group is turning-on to the condition that only the second LED group is turning-on on the basis of a current flowing through the second LED group.