Low voltage sensor for dryer

In a fabric treatment apparatus having means defining a fabric treatment zone and means for treating fabrics placed therein to a predetermined condition, a control for terminating said treatment operation comprising:

• a source of timing signals;
• a microcomputer counter means arranged to be incremented in accordance with pulses derived from said source of timing signals;
• a low voltage sensing means associated with said fabric treatment zone for sensing a parameter related to said predetermined fabric condition and operative to reset said counter at a rate dependent upon the level of said sensed parameter;
• said low voltage sensing means comprising
• sensing means arranged to contact the fabric load;
• comparator means arranged to compare the sensed parameter with a predetermined value and to emit a low voltage level signal if above and a high voltage level signal if below said predetermined value;
• microcomputer means arranged to receive said signal and reset said counter if said sensed parameter is greater than said predetermined value;
• and
• circuit means for terminating said fabric treatment operation in response to the accumulation of a preselected count in said counter means.

A method of controlling a fabric treating apparatus having a treatment zone and means for effecting at least one fabric treating operation, comprising the steps of:

• (a) initiating a fabric treating operation;
• (b) sensing a parameter related to the condition of the fabric within the treatment zone;
• (c) generating a low signal when said sensed parameter is more than a predetermined amount, and otherwise generating a high signal;
• (d) counting pulses from a source of timing signals on a counter;
• (e) reading said signal at spaced intervals in time;
• (f) generating a valid signal whenever a given consecutive number of said readings indicate a sensed parameter more than a predetermined amount;
• (g) repeatedly terminating and restarting the count in the counter in response to the generation of said valid signal;
• and
• (h) terminating the fabric treating operation upon the accumulation of a preselected count in the counter.

A method of controlling a fabric drying apparatus having a drying zone and means for effecting at least one fabric drying operation, comprising the steps of:

• (a) initiating a fabric drying operation by flowing temperature conditioned air through a drying zone charged with a batch of fabrics to be dried;
• (b) sensing the moisture content related to the condition of the fabric within the drying zone;
• (c) generating a low voltage level when a wet condition is sensed;
• (d) generating a high voltage level when a dry condition is sensed;
• (e) counting pulses from a source of timing signals on a counter;
• (f) reading said voltage level at spaced intervals of time;
• (g) generating a valid wet signal whenever a given consecutive number of said readings indicate a wet condition of the fabric within the drying zone;
• (h) repeatedly terminating and restarting the count in the counter in response to the generation of said valid wet signal;
• and
• (i) terminating the fabric drying operation upon the accumulation of a preselected count in the counter,
• whereby termination will coincide with an optimum dryness condition.