Apparatus and method for controlling or monitoring electric welding processes

Claim 3

Apparatus for monitoring, controlling and regulating the course of electric welding processes with a consumable electrode carrying a welding voltage with respect to a workpiece, comprising means for generating said welding voltage between said electrode and said workpiece, a transducer for producing a signal commensurate with the welding voltage, a first means (K1) for comparing the welding voltage signal with a first adjustable threshold value (USCH1) and generating a signal when the welding voltage signal is above said first threshold value, first timing means for timing a first period of time of a first adjustable duration, a first AND-gate (U1) having an output terminal and being connected with a first input terminal to said first comparing means and with a second input terminal to said first timing means (M1), a second means for comparing said welding voltage signal with a second adjustable threshold value aNd generating an output signal when said welding voltage signal is below said second threshold value, second timing means for timing a second period of time of a second adjustable duration, a second AND-gate (U2) having an output and being connected with a first input to said second comparing means and with a second input to said second timing means, a third means for comparing said welding voltage signal with a third adjustable threshold value and generating an output signal when said signal is below said third threshold value, an adjustable pre-selection counter (Z) connected to an output of said third comparing means for counting of the output signals from said third comparing means and generating an output signal when a preselected number is reached, third timing means for timing a third period of time of a third adjustable duration, a third AND-gate (U3) having an output and being connected with a first input to said output of said counter and with a second input to said third timing means, an OR-gate (O) having an output and being respectively connected with its inputs to said outputs of the said AND-gates (U1, U2, U3) and a pulse shaper (I) connected to the output of said OR-gate.

Claim 4

Apparatus for monitoring, controlling and regulating the course of electric welding processes with a consumable electrode carrying a welding voltage with respect to a workpiece, comprising means for generating said welding voltage between said electrode and said workpiece, a transducer for producing a signal commensurate with the welding voltage, a first means (K1) for comparing the welding voltage signal with a first adjustable threshold value (USCH1) and generating a signal when the welding voltage signal is above said first threshold value, first timing means for timing a first period of time of a first adjustable duration, a first AND-gate (U1) having an output terminal and being connected with a first input terminal to said first comparing means and with a second input terminal to said first timing means (M1), a second means for comparing said welding voltage signal with a second adjustable threshold value aNd generating an output signal when said welding voltage signal is below said second threshold value, second timing means for timing a second period of time of a second adjustable duration, a second AND-gate (U2) having an output and being connected with a first input to said second comparing means and with a second input to said second timing means, a third means for comparing said welding voltage signal with a third adjustable threshold value and generating an output signal when said signal is below said third threshold value, an adjustable pre-selection counter (Z) connected to an output of said third comparing means for counting of the output signals from said third comparing means and generating an output signal when a preselected number is reached, third timing means for timing a third period of time of a third adjustable duration, a third AND-gate (U3) having an output and being connected with a first input to said output of said counter and with a second input to said third timing means, an OR-gate (O) having an output and being respectively connected with its inputs to said outputs of the said AND-gates (U1, U2, U3) and a pulse shaper (I) connected to the output of said OR-gate.