Method for operating a clothes drying appliance and clothes drying appliance

1. A method for operating a clothes drying appliance, comprising:

determining a salt content of moisture emanating from the drying clothes;

measuring a current running through the clothes; and

determining a moisture content of clothes from the measured current by taking into account the determined salt content of the moisture.

2. The method according to claim 1 , wherein the moisture content of clothes is determined by

determining a gradient of a curve formed from pairs of varieties representing the moisture content over time, and

setting at least one target value of a drying cycle based on the gradient.

3. The method according to claim 2 , wherein the at least one target value is set by

correcting the at least one target value for a pre-determined salt content by adding an offset value,

wherein the offset value is based upon a difference of the determined gradient and a gradient corresponding to the pre-determined salt content.

4. The method according to claim 2 , wherein the curve is a linear curve.

5. The method of claim 2 , wherein the curve is an exponential curve.

6. The method according to claim 2 , further comprising

storing gradients from multiple measurements as an average gradient, and

setting the at least one target value based on the average gradient.

7. The method of claim 2 , wherein the at least one target value comprises a target value representative of the moisture content at which a target time for terminating the drying cycle is reached.

8. The method according to claim 1 , further comprising:

applying an AC voltage signal to the clothes to produce an AC current,

measuring the AC current for consecutive samples,

generating from the measured AC current for the consecutive samples an envelope signal,

generating a series of maximum values from n consecutive samples of the envelope signal, and

passing the series of the maximum values through a logarithmic filter to produce a series of filtered values, wherein the filtered values or a curve derived from the filtered values represent the moisture content of the clothes over time.

9. The method according to claim 8 , wherein a target value of a drying cycle representative of the moisture content at which a target time for terminating the drying cycle is reached is based on the filtered values.

10. The method according to claim 8 , wherein the envelope signal comprises consecutive peak values extracted from the measured AC current over a corresponding sample time.

11. The method according to claim 8 , wherein the filter uses a relation comprising y(m)=y(m−1)+log(a, x(m)−y(m−1)), wherein y(m) is an m-th filtered value, y(m−1) is a previous filtered value, a IS a parametric log base and x(m) is an m-th maximum value received from the filter.