Small electrical appliance with protective circuit

Small electrical appliance comprising a hair removal device or a toothbrush, comprising:

• an electric load, wherein the electric load heats up during operation;
• a measuring circuitry for measuring an electrical parameter of the electric load;
• a temperature sensor arranged spatially separated from the electric load;
• and
• control circuitry adapted to protect the electric load from overheating by controlling the electric load based on the electrical parameter of the electric load and an output of the temperature sensor, the control circuitry is adapted to protect the electric load from overheating by controlling the electric load based on a thermal model of the electric load, wherein the thermal model comprises estimating a temperature of the electric load based on a first sub-model indicative of the ambient temperature, a second sub-model indicative of a power dissipation of the electric load, and a third sub-model indicative of a temperature of the electric load at said ambient temperature and said power dissipation.

Method for protecting an electric load of a small electrical appliance comprising a hair removal device or a toothbrush, from overheating, wherein the electric load heats up during operation of the small electrical appliance, the method comprising

• measuring an electrical parameter of the electric load;
• measuring a temperature with a temperature sensor arranged spatially separated from the electric load;
• and
• controlling the electric load so as to protect the electric load from overheating based on the electrical parameter of the electric load and an output of the temperature sensor, wherein a temperature of the electric load is estimated using the output from the temperature sensor comprising an ambient base temperature and a heating effect derived from the electrical parameter.

Small electrical appliance comprising a hair removal device or a toothbrush, comprising:

• an electric load, wherein the electric load heats up during operation;
• a measuring circuitry for measuring an electrical parameter of the electric load;
• a temperature sensor arranged spatially separated from the electric load;
• and
• control circuitry adapted to protect the electric load from overheating by controlling the electric load based on a power dissipation of the electric load estimated from the electrical parameter of the electric load and an output of the temperature sensor, wherein a temperature of the electric load is estimated using the output from the temperature sensor comprising an ambient base temperature and a heating effect derived from the power dissipation of the electric load.