Power supply device

A heating device, comprising:

• a heating element to be heated by being supplied with power;
• a power supply unit configured to supply power to the heating element;
• a current sensing unit connected between the power supply unit and the heating element and configured to measure a current flowing to the heating element;
• a feedback unit configured to provide a feedback signal to the power supply unit according to a change in the current measured by the current sensing unit;
• and
• a control unit configured to vary the feedback signal according to the current measured by the current sensing unit,
• wherein the power supplied by the power supply unit varies according to the feedback signal.

A lens module, comprising:

• a lens;
• and
• a heating device comprising a heating element disposed on a surface of the lens,
• wherein the heating device comprises:
• a power supply unit configured to supply power to the heating element;
• a current sensing unit connected between the power supply unit and the heating element and configured to measure a current flowing to the heating element;
• a feedback unit configured to provide a feedback signal to the power supply unit according to a change in the current measured by the current sensing unit;
• and
• a control unit configured to vary the feedback signal according to the current measured by the current sensing unit,
• wherein the power supplied by the power supply unit varies according to the feedback signal.