Specifications

THEORY OF OPERATION

Model F/DF-T01-A Feeder operation produces a vibrating stroke on the surface of the feeder trough. The

stroke is obtained by the electromagnet pulling the trough sharply down and back and then allowing it to

spring up and forward. Repeated at high speeds (3600 v.p.m. at 60 cycle power supply), this action

produces a definite vibrating movement on the trough surface.

The F/DF-T01-A Feeder requires the use of separate control which contains a rectifier (SCR), used to

convert alternating current into rectified current. Service Instructions are included with the control.

Figure 1 illustrates a typical a-c sine wave and a typical r-c sine wave (the type of pulsating current which

is required to operate the feeder). The coil is energized only by the portion of the sine wave shown as a

solid line of the r-c sine wave. The broken line represents the portion of the sine wave which is blocked by

the rectifier. The blocked portion does not reach the feeder coil and during this time the feeder coil is de-

energized.

When the coil is energized, the core becomes magnetized and attracts the armature assembly. This pulls

the armature, trough mounting bracket and trough down and back towards the core. This pull is against

the mid-point of the leaf spring stack, flexing the springs.

FIGURE 1–THE RECTIFIED SINE WAVE

Each power half cycle is followed by a half cycle of blocked current flow during this half cycle, power is not

available to the coil and the coil becomes de-energized. With the coil de-energized, the magnetic pull

between the core and armature is released and the leaf spring system is permitted to spring back to (and

slightly through) its normal position. This pulls the trough, bracket and armature assembly up and forward.

On the next power half cycle, the trough, trough mounting bracket and armature are again pulled down

and back. On the next no power half cycle, the trough, trough mounting bracket and armature assembly

are again pulled up and forward. Thus, during operation, the trough is continually vibrating along a straight

line path.

The unit is mechanically adjusted to limit the travel of the armature so it does not strike against the face of

the core. The space between the armature and core is called the “air gap”. The size of the air gap is critical

to good feeder operation. Instructions concerning the air gap are on page 6.