Half-wave control
3000 vibs / min
50 Hz operation
Only one half of the mains sine wave is controlled. The vibrating frequency
is the same as the mains frequency.
3000 vibrations/ min at 50 Hz mains frequency
3600 vibrations/ min at 60 Hz mains frequency
Soft start
To prevent a sudden switch-on to full feeder throughput; a ramp-up time is
used instead.
Purpose: To reduce the likelihood of coil hammering and components being
thrown off the feed track
Soft stop
The feeder is ramped down when the feeder is switched off by using the
enable input or track control.
Purpose: To reduce product storage changes
Umax / Umin
A facility to adjust the maximum and minimum output voltage levels of the
control equipment; the set-point range can then be varied between these
limits.
Purpose: For adapting different feeders to work with a controller
Track control
A component sensor is used, in conjunction with the controller, to maintain
a semi-constant level (queue) of product around a fixed point (sensor posi-
tion
Purpose: To reduce the unnecessary running time of feed equipment and
deterioration of product finish
Component high/low
level control
Control of component storage, between two track sensors
Purpose: To reduce the unnecessary running time of feed equipment and
deterioration of product
ton / toff
On/off switching time-delays
Purpose: To adjust a feeders response to track sensor signals
Pre-feeder control
Replenishment of product i response to a level control sensor,e.g. fitted in a
bowl feeder. When the depth of components drops below set a certain
level, the pre-feeder switches on and “tops-up” the feed system.
Coarse/fine control
Operation with two feeder speeds:fast and slow
Pulsed operation
Feeder runs with a pulsing, on/off action,e.g. to separate components
Accelerometer or am-
plitude sensor
A sensor to control the actual amplitude of a vibratory feeder
Can be used either for monitoring or as a feedback transducer for amplitude
regulation.
Mill controller
Used with small capacity grinding mills, to ensure that a mill is fed with the
optimum throughput of material. The feeder is regulated in response to the
loading of the mill. The motor current is used to monitor to mill loading.
Motor current increases as a greater amount of material is fed and so the
feeder throughput is reduced. When the motor current drops the feeder
throughput is increased.
Material sensor
Component sensor
A sensor that determines if components are present or not at a particular
point
This sensor can be a light barrier, initiator or a switch.
PNP / NPN output
Depending on its construction, a sensor can give out a positive signal e.g.
+24V, or in the case of an open collector provides a ground return path.
When a positive signal is provided this is referred to as a PNP output. When
the output is switched to earth this is referred to as an NPN output.
Active/passive
photo-electric sensor
Active photoelectric sensors have an integrated switch amplifier and give a
definite output signal that is either PNP or NPN.
For passive photoelectric sensors there must be provision in the control unit
for a photo-receiver to be used.
Namur sensor
A sensor that reacts to the proximity of metallic materials with a resistance
change
2 wire system
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