Abstract: A probeless energy delivery controller for a resistance spot welding system includes a power supply module that generates a first current and a power delivery module configured to generate a second current from the first current. The current is delivered to a first electrode and a second electrode that have at least two weld pieces interposed there-between. As the current flows through the weld pieces, the resistance and temperature of the weld pieces increase such that the weld pieces melt. The system further includes a voltage control module that receives a current reading indicating a value of the second current, estimates a resistance of the weld pieces based on the value of the second current, and determines a phase angle for setting a voltage outputted by the power supply module based on the estimated resistance and a power profile. The power supply module generates the first current based on the phase angle.

Abstract: A probeless energy delivery controller for a resistance spot welding system includes a power supply module that generates a first current and a power delivery module configured to generate a second current from the first current. The current is delivered to a first electrode and a second electrode that have at least two weld pieces interposed there-between. As the current flows through the weld pieces, the resistance and temperature of the weld pieces increase such that the weld pieces weld together. The system further includes a voltage control module that receives a current reading indicating a value of the second current, estimates a resistance of the weld pieces based on the value of the second current, and determines a phase angle for setting a voltage outputted by the power supply module based on the estimated resistance and a power profile. The power supply module generates the first current based on the phase angle.

Abstract: A welding method and apparatus are disclosed wherein a plurality of stacks of metal sheets are clamped together in sequence at a welding site between a pair of electrode caps across which welding current is supplied to spot weld together the sheets in each of the stacks in a series of welding operations in a production run. The electrode caps are pressed against the sheets in each of the stacks when each of the stacks is at the welding site with an applied force that includes a closing force to clamp the sheets together in a surface-to-surface interface fit plus a predetermined interjoint force that is increased progressively throughout the production run.

Abstract: A method and system for controlling a welding system collects material thickness data and material type data for a plurality of materials to be welded. A non-linear power profile is generated having a discrete stepped approximation of power over a period of time based on the material thickness data and the material type data to produce a desired current amount at a specific time during welding of the plurality of materials.

Abstract: A method for estimating weld nugget diameter includes receiving current and voltage inputs, a time input, and a force input. In certain embodiments, the method also uses other weld parameters including type of material, type of stack, stack thickness, applied force, preheat current, RMS value of weld current, weld level, and weld time. The method further determines a resistance curve based on the current and voltage inputs, and time input. It also derives parameters from the resistance curve, and determines a weld nugget diameter estimate based on both resistance parameters.

Abstract: A welding method and apparatus are disclosed wherein a plurality of stacks of metal sheets are clamped together in sequence at a welding site between a pair of electrode caps across which welding current is supplied to spot weld together the sheets in each of the stacks in a series of welding operations in a production run. The electrode caps are pressed against the sheets in each of the stacks when each of the stacks is at the welding site with an applied force that includes a closing force to clamp the sheets together in a surface-to-surface interface fit plus a predetermined interjoint force that is increased progressively throughout the production run.

Abstract: A method for estimating weld nugget diameter includes receiving current and voltage inputs, a time input, and a force input. In certain embodiments, the method also uses other weld parameters including type of material, type of stack, stack thickness, applied force, preheat current, RMS value of weld current, weld level, and weld time. The method further determines a resistance curve based on the current and voltage inputs, and time input. It also derives parameters from the resistance curve, and determines a weld nugget diameter estimate based on both resistance parameters.

Abstract: A method to continuously identify and recognize microbiota in water comprises random sampling of a water source, directing the sample to an optical plane where microscopic CCD/video images are obtained and stored in analogue and digitized form. Statistical data on organism type and number will be simultaneously collected. Using novel software the digitized images are filtered and segmented. Segmented images will activate software to extract morphological and motion-related features. The extracted features are used to search a database for matching, specific microbiota profiles in a recognition and classification step. Software will enable classification, together with the statistical data will ascertain the biological status of the water. A flizzy-logic decision tree will trigger actuator/annunciator relays that manipulate water intake valves and send signals through modems for telephone warning messages.