Appliance and power supply therefor

An appliance having a fluid heating element,

• a power supply having an input for coupling to an AC voltage,
• a rectifier coupled directly or indirectly to the input for receiving and rectifying an AC voltage,
• a voltage dropping resistor that forms the fluid heating element, the voltage dropping resistor coupled in the circuit to provide a voltage drop between the input and an output of the power supply, and
• a smoothing circuit coupled to receive the rectified AC voltage and provide an output voltage, the smoothing circuit comprising:
• at least two capacitors to stabilise the output voltage, and
• a switching network to switch the capacitors between a first configuration with a first effective voltage rating, and a second configuration with a second effective voltage rating.

A power supply generating a DC output voltage from an AC mains supply,

• a rectifier, adapted for coupling to an AC mains supply,
• a voltage dropping resistor,
• a first and a second capacitor, and
• a first and a second switching device,
• wherein said first and second capacitor charge in a series circuit arrangement and discharge in a parallel circuit arrangement to provide said output voltage, and said voltage dropping resistor is connected in series with at least the charging circuit arrangement.

A DC power supply generating a controlled output voltage,

• a rectifier, which receives AC from a mains supply,
• a voltage dropping resistor, and
• a switch connected in series between said rectifier and a variable capacitance
• wherein said switch controllably allows current to flow from the output of said rectifier to said variable capacitance to provide said controlled output voltage.