Walker Magnetics SMART-B SERIES - Manual (Page 11)

O.S. WALKER Co., Inc. SMART-B Control
SMART B MANUAL DD-14283J Rev J, March 30, 2011
4-2
4.1.4 Workpiece Material
Low carbon steel such as SAE 1020 steel, are nearly as good conductors of magnetic
lines of force as pure iron. However, many other alloys contain non-magnetic materials,
which reduce the ability of magnetic lines of force to flow. An alloy such as SAE 300
series stainless steel is almost as poor a conductor of magnetic lines of force as air.
Type 416 stainless steel is considered magnetic, but it contains enough chromium so that
a magnet can develop only about one half as much magnetic force as it can on an SAE
1020 steel workpiece. Also, because of the carbon content, the force developed on typical
cast iron is less than one half that developed on SAE 1020 steel. (Chilled cast iron further
reduces the force to less than one quarter.)
Additional concerns regarding Magnetic Holding should be forwarded to O. S. Walker,
Inc.
4.2 Release
(Red Push-Button)
Selecting the Release function initiates an automatic release cycle. During the release cycle,
the output voltage produced by the control is reduced from full to zero in a predetermined
number of equal pulses (see Figure 4-1). The polarity of these pulses alternately reverses
from negative to positive as the magnitude of the voltage decreases. The SMART-B can
generate a maximum of sixteen pulses per release cycle, but is set at the factory for eight.
The Release indicator light will flash ON and OFF to show that release is taking place, and
will remain ON when the cycle is complete.
The duration of each pulse is automatically controlled. The time between pulses is
automatically adjusted by the control for the optimum Release cycle time.
The SMART-B has an adjustment for the number of pulses per Release cycle. This
adjustment allows the operator to select the number of pulses it takes to get the fastest, most
complete release of a part.
The adjustment for the number of demagnetization pulses per Release cycle is done using
the full, residual, release pushbuttons, and the Variable potentiometer. To adjust the number
of release pulses, the control must be "at the end of the release cycle". The procedure for
adjusting the number of Release pulses is as follows:
1. Hold the Release button down and PRESS the Full button. With some control revisions
you may have to press the Full button again after you have let go of the Release
button.
2. Using the table below, you can adjust the number of release pulses by turning the
Variable adjustment knob.
Number of Release Pulses 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Variable Lamp/LED X X X X X X X X
Residual Lamp/LED X X X X X X X X
Full Lamp/LED X X X X X X X X
Release Lamp/LED X X X X X X X X
X indicates lamp/led is on.