IMED - RUDDER ANGLE INDICATOR...IMED’s Rudder Angle Indicator (RAI) is a rudder angle/order...

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IMED - RUDDER ANGLE INDICATOR

Description

IMED’s Rudder Angle Indicator (RAI) is a rudder angle/order display unit. The angle is displayed using high intensity LEDs for clear visibility in outdoor helm stations. The design is microcontroller based which makes it easy to configure and eliminates the need for any trim pots etc. IMED’s RAI will work directly off most existing rudder feedback units, basically any potentiometer from 1kΩ to 100kΩ.

The RAI only needs to be set up once at the time of installation. It then stores all the essential data in the microcontroller’s non-volatile memory. The configuration process is simple and makes use of the three push buttons mounted on back of the RAI. LEDs can also be dimmed by using an external dimmer making the RAI user friendly during night time.

___________________________________________________________________________________________ IMED Ltd - 5/160 Beaumont St, Westhaven, Auckland, NZ – PO Box 47671, Ponsonby 1144, Auckland, NZ Phone: +64 9 373-2422 - Fax: +64 9 373-2423 - Mobile: +64 21 303399 www.imed.co.nz


Operation

As the rudder angle changes, LEDs on the RAI display this angle in real time. There are two versions of the RAI unit available:

Linear Scale Expanded Scale

On the Linear model the LEDs follow a linear scale, as shown below in figure 1. The angle displayed by each LED is constant throughout the whole range of rudder’s rotation.

Figure 1 - Linear Scale LEDs

The Expanded Scale model is different because of the non-linear nature of its display. This is shown below in figure 2. The LEDs give more detail of the rudder angle close to the centre position but as the rudder angle increases the scale of display is expanded and becomes less detailed.

Figure 2 - Expanded Scale LEDs



Configuration

The RAI has three pushbuttons labelled ‘P’ (Rudder at Port), ‘C’ (Rudder at Centre) and ‘S’ (Rudder at Starboard). These buttons are used to setup the RAI.

These buttons are shown in figure 3 below.

Figure 3 - Pushbuttons for setup

A specific setup procedure must be followed to setup the RAI for use. As mentioned above, there are two versions of the RAI available. Each one has a different setup procedure. This is detailed in the next section for each RAI model.

A “Receipt LED”, located at the back of the RAI, lights up to indicate when an input has been received. This LED should be used as a visual confirmation of a value being received and saved into the RAI memory. The location of this “Receipt LED” is shown below in figure 4.

Figure 4 - Receipt LED highlighted by the red square



Initial Setup

For best performance the potentiometer’s movement should have a large span from hard to Port to hard to Starboard. i.e. having a 10 turn, 10 K pot, which only does 1 full turn over the full span of the rudder will not work as well as having a single turn, 10 K pot doing close to one full rotation.

‘P-‘ and ‘P+’ connections for the potentiometer can be swapped and this may be required for correct operation. The RAI will only function if ‘PW’ is at lowest voltage (with reference to P-) when the rudder is hard to Starboard and highest voltage when the rudder is hard to Port.



Setup Procedure – LINEAR MODEL

For the RAI to operate, three points need to be programmed. These points are: Hard to Port, Hard to Starboard and the Centre point. Each point is illustrated in figure 5 below for a visual reference.

Figure 5 - Three configuration points for Linear Model

Step 1: Move rudder to ‘Hard to Port’.

Step 1A: Press and hold ‘P’ until ‘Receipt LED turns on’.

Step 2: Move rudder to ‘Centre’.

Step 2A: Press and hold ‘C’ until ‘Receipt LED turns on’.

Step 3: Move rudder to ‘Hard to Starboard’.

Step 3A: Press and hold ‘S’ until ‘Receipt LED turns on’.

Upon completion of the final step, the RAI should display the rudder at ‘Hard to Starboard’ until it is moved to a new position.



Setup Procedure – EXPANDED SCALE MODEL

There are five points that need to be programmed for the RAI to operate. The RAI will not function unless ALL points are programmed. The five points are Hard to Port, Hard to STBD, Centre and two arbitrary points A & B, one each side for the expanded scale. Each point is illustrated in figure 6 below for a visual reference.

Figure 6 - Five configuration points for Expanded Scale Model

Step 1: Move rudder to ‘Hard to Port’

Step 1A: Press and hold ‘P’ until ‘Receipt LED turns on’.

Step 2: Move rudder to ‘Point A’.

Step 2A: Press and hold ‘P’ AND ‘C’ until ‘Receipt LED turns on’.

Step 3: Move rudder to ‘Centre’.

Step 3A: Press and hold ‘C’ until ‘Receipt LED turns on’.

Step 4: Move rudder to ‘Point B’.

Step 4A: Press and hold ‘S’ AND ‘C’ until ‘Receipt LED turns on’.

Step 5: Move rudder to ‘Hard to Starboard’.

Step 5A: Press and hold ‘S’ until ‘Receipt LED turns on’.

Upon completion of the final step, the RAI should display the rudder at ‘Hard to Starboard’ until it is moved to a new position.



Connections

Figure 7 – Screw Terminal for wiring connections

The RAI has a 6-way screw terminal. The part is highlighted in figure 7 above. The terminals are labelled and each label is detailed below:

P- Negative supply for RAI Potentiometer PW Connect to potentiometer’s wiper terminal (Variable 0V t0 4.5V) (I = negligible) P+ Positive (Regulated 4.5V) supply for RAI Potentiometer (Imax = 4.5mA) Dim LED Negative – connect to 0V for full brightness or via resistor or dimmer for

selectable brightness (Imax = 0.5A). V- 0V (or Negative) V+ +24 V DC Power Supply (Imax = 0.5A)

o External 2A fuse on the V+ line is recommended for wiring protection

Below in figure 8 is the electrical wiring diagram for the RAI and the potentiometer. A screened cable should be used for all connections to minimise any stray noise/signals getting to the RAI.

Figure 8 - Electrical Wiring Diagram



Parallel Operation

It is possible to run up to 3 RAIs off the same potentiometer so rudder angle can be displayed at separate locations (e.g. Port and Stbd helm stations) at the same time. Careful attention must be given to wiring for a parallel operation. Wrong wiring may result in permanent damage to the RAIs. Figure 9 below shows wiring diagram for paralleling three RAIs.

Figure 9 - Wiring diagram for Paralleling three RAIs



Dimensioned Drawings (All dimensions in mm)

Figure 10 - Dimensioned drawing of the RAI



Ordering Information

Part Number: IME-RAI _ _

L – Linear Model ‘X’ (LED Standoff): Refer figure 10 in ‘Dimensioned Drawings’

E – Expanded Scale Model

Example:

For a Linear RAI with 9mm LED Standoffs: IME-RAI L 9

FOR ORDERING OR FURTHER INFORMATION PLEASE CONTACT IMED LTD.

E-mail: [email protected]

Ph.: +64 9 373 2422

Web: www.imed.co.nz


IMED - RUDDER ANGLE INDICATOR...IMED’s Rudder Angle Indicator (RAI) is a rudder angle/order...

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