INSTRUCTIONS for SA1 and SA1-S


OPERATING SEQUENCE: The train is positioned at the left end of the track at the start of the sequence. On powering the unit it operates as follows:

1.Adjustable time delay indicated by the red and green LEDs flashing.

2.Signal 1 relay activated (SA 1-S only).

3.Red LED lights for approx 4 seconds

4.Green LED lights and Train gradually accelerates to maximum speed.

5.On reaching the train detector connected to TD1 input red LED lights and train slows.

6.On reaching the train detector connected to TD4 input train stops and red and green LEDs flash for the adjustable delay

7.Signal 2 relay activated (SA 1-S only).

8.After a short delay indicated by the red LED the green LED will light and the train will accelerate to the left.

9.On reaching TD2 the train will brake and red LED lights on SA1 board.

10.On reaching TD3 the train will stop and the sequence will continue from 1.

Just before the train departs the signal will change to green, it returns to red a few seconds after the train has left.

LED INDICATIONS

GREEN LED LIT = Train accelerating or travelling at maximum speed.

RED LED LIT = Train braking or stopped.

RED and GREEN LEDS flashing alternately = Adjustable Time Delay. The length of time of the delay is proportional to the duration of the flashes.

RED and GREEN LEDS both lit = Overload. IE short circuit on track.

INSTALLATION

Power connections

The SA boards are designed so that the control electronics and track power can be separated. This allows either the whole unit to be powered from a single AC or DC power supply; or the track power from a controller and the control electronics from a separate AC or DC power supply. The reason for using a separate controller is to allow the train to be slowed or stopped manually and the maximum speed to be set by the controller setting. This option is of more use with other units such as the SA5 SA6 SA7 and SA8. Feedback controllers will not work with the SA units.

12 volt DC supply

This option powers both the control electronics and track from a 12 volt DC power source. Put a link wire the 5 way terminal block and connect a 12 volt DC supply with positive to the "+" terminal and negative to the "o" terminal.. When first powered the train must move from left to right (move towards towards D1 and D4). If it moves in the other direction swop over the two wires to the track.

Using a smoothed regulated DC power supply will give pure DC at the track suitable for N gauge locomotives and coreless motors.

AC Supply

Replace the wire link with a diode, the band on the diode must face the direction shown in the diagram. The supply to the track with an AC supply will be unsmoothed DC. This may cause damage and overheating of N gauge locomotive motors but is satisfactory for OO gauge. The DC on the track may be smoothed by using a (electrolytic) capacitor. The capacitor must be attached with its negative leg to the rightmost terminal. Using the capacitor will make the track power smooth and suitable for N gauge and coreless motors.

Train controller

Remove the link and connect as shown.

The automatic control only works with one direction setting of the controller the other direction setting will allow trains to be reversed manually. Feedback controllers will not work with the SA board.

TRAIN DETECTORS

These can be either IRDOT-1 or reed switch and magnet.

IRDOT-1 This must be powered from the same supply as the control electronics every terminal 6 connecting to "o" and every terminal 1 to "+".

Terminal 2 connects to the appropriate terminal D1 D2 D3 or D4. Refer to diagram at top of first page ie train detector at TD1 to D1 train detector at TD2 to D2 etc.


REED SWITCH One end of each reed switches is connected to the "o" terminal and the other end to the appropriate input ie D1 D2 D3 or D4.

LOCATION OF TRAIN DETECTORS: If IRDOT-1 are used then the outer train detectors can be positioned where the leading ends of the trains stop. If reed switches are used there positioning must correspond to the position of the magnet on the train. Allow the same braking distance at each end of the line.

USING 3 OR 2 DETECTORS: For a short length of track a single start slowing (for both left to right and right to left trains) detector can be positioned in the centre of the track and wired to both D1 and D2. For a line with one end hidden (in a tunnel for example). Sudden stops can be made with a single detector at the hidden end. To do this the start slowing and stop terminals are both wired to a single detector in the stop position. Ie D1 and D4 are both wired to the same detector (in effect this is achieved by a link wire between D1 and D4 and a second wire from either of these linked terminals to terminal 2 of the IRDOT-1.) Similarly the SA1 can be wired for a sudden stop at both ends, the gradual slowing may not be necessary if the train always runs at a very slow speed. In this case D2 and D3 are also linked together.

NOTE: the SA1will not recognise the stop detector until it has received the start slowing detectors input. This is the reason it is necessary to link the start slowing and stop terminals together.

CONNECTIONS TO SIGNALS (SA1-S ONLY):Relays on the SA board switch the signals. The relays will handle up to 2 amps of current. These contacts are not electrically connected to the rest of the SA board. Wiring a signal to the SA board is identical to wiring to a change over switch. The internal relay contacts are shown as thick lines. "sc" is the common to which one wire of the signals power connects. This is switched to one of the adjacent terminals by the SA4-S to light either the red or green. To give a realistic effect there is a short pause between the points changing and the signal changing to green then another delay before the train moves away.

The signals can use the same power as the SA1-S or a separate supply. The diagram shows wiring common positive LED signals using the SA1-S supply. The diode is only required if an AC supply is used. A resistor (usually supplied with the signal) is used with each signal to limit the current through the LEDs.

Diagram on left shows common negative led signals powered from a separate supply. Diode is only necessary if the supply is AC.

Diagram on right shows bulb signals. Use of resitors depends on voltage of bulbs and voltage of power supply. Refer to signal manufacturers instructions.

LED SIGNALS

These are wired in the same way as BULB signals but the LED polarity must be correct and current limiting resistors used. (two resistors shown as rectangles on the diagram). The diagram shows common negative signals. This means that the signal has been internally wired so that the two short legs (cathodes) of the LEDs are wired together within the signal If an AC supply is used the diode shown in the diagram is required. If DC supply the diode is not necessary.

SEMAPHORE SIGNALS

The relay can be used to operate semaphore signals by using it to operate a slow motion point motor or a relay.. The relay is the type with a moving arm which can be adapted to move the signal.

TESTING AND SET UP ADJUSTMENTS

The SA1 can be tested without the detectors. To do this, touch a piece of wire between the "o" terminal and appropriate "D" terminal. The terminals operate in a sequence. Operating D4 will not stop the train if D1 has not been operated first. The signal applied to the inputs is 0 volts. Hence the operation can be verified by touching the input terminals in turn with a piece of wire connected to terminal "o".

There are adjustments on the board for maximum speed, minimum speed delay time and rate of acceleration/braking. The train will accelerate to the maximum speed setting and brake to the minimum speed setting. Turn the variable resistors with a fine screwdriver to the end of travel positions. Initially adjust to give

delay time=min (clockwise),

min speed=min(clockwise),

max speed=max (anticlockwise)

rate of braking /acceleration = abrupt (clockwise).

All the variable resistors turn through 3 quarters of a revolution.

With a train at the left hand end of the line apply power. After the variable delay (green and red flashing) followed by the green LED lighting the train should travel towards the right. (towards D1 and D4). If it travels towards the left, swop over the two track power connections. On reaching train detector 1 the red LED should be lit. And the train should rapidly slow to a halt.

Adjust the minimum speed control until the engine is moving at its slowest reliable speed. When the engine reaches the train detector at the end of the line (TD4) it will stop and the red and green LEDs will flash

The purpose of the minimum speed control is so that a braking train does not slow to a stop before reaching the end of the line.

Whilst the green LED is lit adjust the maximum speed control until the train is travelling at the desired maximum speed. When both these controls are set then adjust the rate of braking/acceleration so that the train slows to its minimum speed at the place where it is to stop.

Finally adjust the delay time to give the desired waiting time at each end of the line.

OVERLOAD PROTECTION

Overload protection is built in to the SA1. If a short circuit occurs on the track due to a train derailing etc then the unit switches off power to the track and lights both the red and green LEDs. Power is restored once the fault is removed. The overload protection is triggered when the current rises above 1 amp.

SIDINGS

It is possible to add one or more sidings at one or both ends of the line. An IRDOT-P is required at the end of each siding. This both changes the points and replaces the train detector at the end of the line. The slow down train detector is positioned before the lines divide.

USING THE SA1 WITH IRDOT-P CONTROLLED SIDINGS

An IRDOT-P is installed at the end of each siding. The IRDOT-Ps are wired to the same power supply as the SA1 and IRDOT1s. Check this wiring is correct by making sure the IRDOT-Ps LED lights when a train is detected. All the "P" terminals of the IRDOT-Ps controlling the left hand sidings are wired together and connected to terminal "D3" of the SA1. IRDOT-Ps at the right hand sidings also have all the "P" terminals connected together and connected to the "D4" terminal of the SA1.


Check the wiring is correct by ensuring a train starting at the left shuttles backwards and forwards before wiring up the points.

A connection is made from terminal "A" of the SA1 to every IRDOT-Ps "I" terminal. The "A" terminal switches to 0V as a train is about to depart. Its purpose is to prevent the IRDOT-Ps falsely triggering when a train is halfway across the points.

CONNECTION TO THE POINTS

The IRDOT-P "R" terminals close momentarily when a train arrives over the IRDOT-P. Wire the point motors to the "R" terminals so that an arriving train causes its point to change ready for the next train to depart after the wait time. Depending upon the number of sidings more than one point may need to change.

Check the shuttle with the points working. A train will leave the left hand sidings first so there needs to be an empty siding at the right hand for this train to enter.

Heathcote Electronics, 1 Haydock Close, Cheadle, Staffs, ST10 1UE TEL./FAX 01538 756800

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