US 5,495,093 AGranted

Soldering apparatus processor having temperature selection, calibration and heating control of tip

AssigneeEdsyn, Inc.

InventorRobert C. Griffith

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Abstract

A soldering system is disclosed having a stored program microcontroller by which one or more temperatures can be selected for a soldering iron tip. The system then automatically maintains such tip temperature during the soldering operation. The programmed microcontroller is coupled through input/output and interface circuits to a heating control that in turn is connected to the iron heater element for switching AC power in units of full waveform cycles across the element while the temperature of the tip is measured by a resistor sensor and an associated bridge measurement circuit so as to produce a signal that is applied to an input of the microcontroller forming a feedback loop. This causes the resistor sensor and hence the iron tip to reach the desired temperature. A thermocouple is provided for measuring and calibrating the actual temperature of the iron tip thus ensuring that the resistor sensor and associated feedback loop causes the microprocessor to drive the heater element as needed to cause the soldering tip to stabilize at the selected temperature. The external thermocouple probe may also be used separately and simultaneously with the soldering operation to ensure that the temperature of a probed component does not exceed a predetermined safe level.

Claims17

Dependent claims

A system for setting temperature of a thermo-electric load and automatically maintaining such temperature, comprising:

microcomputer means including program storage means for storing a computer program for controlling the operation of said microcomputer means;
input/output means connected to said microcomputer means;
heater control circuit means operatively connected between a thermoelectric load and said input/output means for electrically heating such load in accordance with a heating control routine of the stored program operating said microcomputer means;
a first temperature sensing circuit means including load sensor means structurally affixed and thermally responsive to such thermoelectric load and having an output connected to said input/output means for providing temperature data signal to said microcomputer for feeding-back temperature to said microcomputer;
user data entry means connected to said input/output means of said microcomputer for causing user-selected temperature set point data to be loaded into said microcomputer and stored, and said computer program including a temperature control routine means for causing the thermoelectric load to be heated by said heater control circuit means to said temperature selected by said user-entered set point data;
a second temperature sensing means including a multipurpose external thermocouple temperature probe separate from said load sensor means and a thermocouple amplifier means connecting said external thermocouple temperature probe to said input/output means of said microcomputer means, and wherein the user selected calibration routine of the program storage means has means for calibrating said thermocouple amplifier means so that a true output voltage of said thermocouple temperature probe is read by said microcomputer means and means for calibrating said load sensor of said first temperature sensing means to said external thermocouple temperature probe of said sensing means;
and
said program storage means of said microcomputer means having a user-selected calibration routine selected by said user data entry means for automatically calibrating said temperature sensing circuit means.

5 more elements

A microcomputer based soldering iron heating, temperature control and calibration apparatus, comprising:

a housing;
microcontroller means and program storage means mounted within said housing, and a computer program for operating said microcontroller means in accordance therewith;
input/output means for said microcontroller means;
digital display means supportively mounted on said housing and coupled through input/output means to said microcomputer means for displaying to a user the settings and operating conditions of said apparatus;
keypad means supportively mounted on said housing for accepting user entries of temperature set point data and calling up calibration routines;
and
wherein the stored computer program for said microcontroller means includes internal interrupt means for interrupting processing by said microcontroller means at predetermined repetitive time intervals, said timed internal interrupt means including a display update routine means and keypad polling routine means for respectively updating said display means with current operating conditions and settings and polling the keypad means for user entries during each of the timed internal interrupts.

4 more elements

Dependencies are inferred from the claim text.