Zapi EPS-AC0, User Manual, Page: 15 / 95

AEMZP0BA - EPS-AC0 - User Manual Page - 15/95
Figure 4–3
The following part numbers resulted suited to work with eps-ac0:
1) CONTELEC twin hall sensors 170° Type code VERT-X 2841 417 225.
2) BOURNS twin potentiometers 180° Type Code 6657S-466-502.
3) MCB twin potentiometers 85° Type Code PMR 410 or PMR426.
The CONTELEC is without brushes but drains a high level of current (about 15 mA).
The MCB has the advantage of a spring in the shaft. This spring neutralizes the
dead zone in the tiller side getting a strongly accurate straight-ahead matching;
unfortunately MCB has a limited angle (85°).
Obviously, the above information states only these parts are suited for the eps-ac0;
no reliability evaluation is given here.
Other sources are possible on request, but must be tested for approval.
4.5 Feedback sensors
Feedback sensors are mandatory to close the loop in manual mode if a twin pot is
mounted on the steering wheel.
Feedback sensors are strongly suggested (to improve safety) in manual mode if a
stepper motor is mounted on the steering wheel (open loop).
Eps-ac0 may handle two different configurations for the feedback sensors:
1) Incremental encoder in the motor shaft together with a feedback potentiometer
on the steered wheel.
2) Incremental encoder in the motor shaft together with one (or two) toggle
switch(es) in the straight ahead (and 90 degrees) position of the steered wheel.
On request, in the closed loop application only, eps-ac0 may work also with two
encoders in the motor shaft together with a straight ahead toggle switch.
4.5.1 Encoder in the motor shaft and a Feedback Potentiometer
One possible arrangement for the feedback sensor consists of (see Figure 4-4):
1) Feedback encoder in the motor shaft.
2) Feedback potentiometer on shaft of the steering motor gear box.