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4-3 WHAT IS PULSING?
Pulsing refers to the alternate raising and lowering of the weld output at a periodic rate.(Ver Fig. 4-16).
The highest value is called peak amperage, and that is the pulse, heats the molten weld puddle, the lowest value is commonly
called background amperage and allows a degree of cooling molten weld puddle.
The weather that increases at peak amperage and remains at this value (it is called pulse width) along with remaining time
in background amperage level, forming a total period cycle or pulse. Then in each cycle there is a pulse.
The number of cycles that occur in a second is known as frequency or cycles per second that we express here as pulses
per second (pps)
The PULSER allows the operator to control the value of:
a)
BACKGROUND AMPERAGE.
b)
PULSE WIDTH
, as percentage of pulse or total cycle.
c) Number of
PULSES PER SECOND (pps)
or frequency.
The combined effect gives the operator better control of penetration, bead width, crowning, undercutting, and puddle sag in out-
of-position welding, specially vertical-up.
Figure 4-16 Pulsed output.
80% On time
Pulses per second
Total pulse period
Amperage
Time
20% On time
Background
amperage period
Amperage
Time
Peak amperage level
(Heat molten
weld puddle)
Background amperage level
(Cool
)
molten weld puddle
Amperage
50% On time
Time
Summary of Contents for ALPHA TIG 252 - DP
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