Hair styling apparatus

A power supply unit for a hair styling apparatus, the hair styling apparatus comprising:

• a body having at least one arm bearing a hair styling heater for heating hair to be styled;
• and
• a temperature sensor arranged to sense a temperature of the hair styling heater and to generate an electrical temperature sense signal that depends on the sensed temperature of the hair styling heater,
• the power supply unit comprising:
• a transformer;
• an AC input and a primary side switch coupled to a first side of the transformer;
• a heater drive output coupled to a second side of the transformer for powering a said hair styling heater;
• a sense input to receive the temperature sense signal;
• and
• a power controller coupled to the sense input,
• wherein the power controller is configured to regulate the output voltage of the heater drive so as to control the temperature of the hair styling heater in multiple steps by adjusting a duty cycle of the primary side switch responsive to a change in the temperature sense signal.

A hair styling apparatus comprising:

• a body having at least one arm bearing a hair styling heater,
• a temperature sensor arranged to sense a temperature of the hair styling heater and to generate an electrical temperature sense signal that depends on the sensed temperature of the hair styling heater;
• a power supply unit external to the body, the power supply unit comprising a transformer, AC input coupled to a first side of the transformer to receive mains AC power, and an output coupled to a secondary side of the transformer;
• and
• a heater controller circuit coupled to the output of the power supply, the hair styling heater, and to the temperature sense signal,
• wherein the heater controller circuit is configured to drive the hair styling heater responsive to the temperature sense signal in multiple steps by controlling an input to the first side of the transformer, and
• wherein the heater controller circuit is located within the power supply unit external to the body of the hair styling apparatus.