초록 ▼

A self-calibrating temperature controller adapted for use in controlling closely the temperature of hot-melt adhesive dispensed from an adhesive supply unit is provided. The temperature controller includes a microcomputer operated under a stored program to perform automatically a self-calibrating op

A self-calibrating temperature controller adapted for use in controlling closely the temperature of hot-melt adhesive dispensed from an adhesive supply unit is provided. The temperature controller includes a microcomputer operated under a stored program to perform automatically a self-calibrating operation. A non-volatile memory is provided for storing RTD values in a lookup table so as to compensate for the non-linearity of the RTD sensors.

대표청구항 ▼

[ What is claimed is:] [1.] An automatic self-calibrating temperature controller adapted for use in controlling closely the temperature of hot-melt adhesive dispensed from an adhesive supply unit, said temperature controller comprising:means for setting a desired temperature in a plurality of zones

[ What is claimed is:] [1.] An automatic self-calibrating temperature controller adapted for use in controlling closely the temperature of hot-melt adhesive dispensed from an adhesive supply unit, said temperature controller comprising:means for setting a desired temperature in a plurality of zones of said adhesive supply unit;temperature sensing means for measuring temperatures in the zones of said adhesive supply unit and for generating analog voltage signals corresponding to said measured temperatures;said temperature sensing means being formed of a plurality of temperature sensors, each of said plurality of temperature sensors being connected in series with a corresponding one of high precision resistors so as to form a voltage generator and a ground potential, the junctions of said plurality of temperature sensors and said corresponding one of the high precision resistors producing said analog voltage signals;means for converting said analog voltages to frequency signals corresponding to said measured temperatures;said means for converting said analog signals being formed of a voltage-to-frequency converter;microcomputer means for comparing said frequency signals to said desired temperatures for generating temperature control signals to regulate the amount of current supplied to heaters located in the zones based upon said comparison;automatic self-calibrating means for generating a low calibration temperature signal corresponding to a low temperature and a high calibration temperature signal corresponding to a low temperature;said automatic self-calibrating means being formed of a calibration resistor circuit having first and second parallel branches connected between said stable voltage generator and the ground potential, said first parallel branch including series-connected first and second precision resistors in which the voltage at their junction produces a value corresponding to the low temperature, said second parallel branch including series-connected third and fourth precision resistors in which the voltage at their junction produces a value corresponding to the high temperature; andsaid microcomputer means being operated under a stored program for continuously scanning said low temperature signal and said high temperature signal and for adjusting said measured temperatures so as to eliminate drift.