Pulse wave shaping principles, A-18 appendix a – Lincoln Electric IM649 Wave Designer User Manual

Page 50

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Our Experiment: We found multiple droplet detachment with an arc length that was too long
at these waveform settings. To attain the proper droplet detachment, we reduced the peak
current value to 250 amps and found improved weld droplet transfer. But reducing the peak
current also caused the arc to be shorter.

Then we needed to lengthen the arc. We reduced the background time to 8.5 milliseconds,
thereby increasing the frequency. The result was a good arc length set at the fixed stickout
of 5/8 in. The droplet transfer was now acceptable and the arc length correct for this stick
out. With the pulse variables set, we could now proceed to make the PowerWave adaptive
(maintain a set arc length over a range of stickouts).

This was a simple application. It shows that the variables interact with each other. The
right solution for a given application may not be the right solution for another.

Wave

Designer features great flexibility to manipulate the waveshape to suit specific applications.

A-18

Appendix A

PULSE WAVE SHAPING PRINCIPLES

WAVE DESIGNER

5. Click on the button and select the

‘Adaptive’ mode. (The status bar now
reads:

While making weld,

set the ‘Peak Voltage’ to

obtain the desired arc length at the 1.00 trim
setting.

Adapting Stickout

For Wire Feed Speed

No Adapt: Maintain constant wire extension

27850043

Adaptive: Maintain constant arc length

Adaptive Type

Peak Voltage

Inductance

30.0

2.625

Fresa

150

PeakAmp 10%, Stepoff 30%, Background 30%, Freq 45%

Start

Adapt Short

End

Our Experiment: We found that a peak
voltage of 27.0 volts resulted in a useable arc
length. (In the “No Adapt” mode, welding with
a fixed 5/8 in. stickout, the actual voltage on
the PowerWave’s voltmeter read about 19
volts. When setting the peak voltage, the
average volts was also about 19 volts. Note
that the actual voltage readouts at the
welding machine will not be the same as the
peak voltage.)

3. Using the adaptive stickout window or the green

adaptive button on the status bar,

select ‘No

Adapt’. The status bar at the bottom of the
screen should read:

. Close the “adapt” window (if

opened).

4. While welding,

adjust the pulse variables to

improve welding performance. Maintain a
constant 5/8 in. stickout (torch tip to work
distance.)