INSTRUCTIONS FOR THE SA-8 AND SA8-S
OPERATION
The SA8 and SA8-S need to detect the train at the approach to the station (A) and at the stopping position (B). These detectors may be either IRDOT-1s or reed switches. Five different types of operation are selected by wiring the detector at A to different terminals. The detector at B is always wired to terminal D4. The different operations are:
- Every train stops at the station. Detector A is wired to terminal D2.
2. Every second train stops at the station. Detector A is wired to terminal D3.
3. Every third train stops at the station. Detector A is wired to terminal "A".
4. Trains stop at the station at random. Detector A is wired to terminal "B".
5. Connecting terminal D1 momentarily to 0volts causes the next train to run non stop through the station. This may be used in conjunction with the storage sidings to give non stop trains from certain sidings.
INSTALLATION
Two train detectors are required. These may be IRDOT-1 or reed switches. The IRDOT-1 and SA8 control electronics must use the same power supply. This supply can be either 12 volt DC or 16 volt AC.
Terminal 6 of the IRDOT-1s and terminal "o" of the SA-8 are connected to the negative or 0 Volts connection of the power supply. Terminal "1" of the IRDOT-1 and terminal "+" of the SA-8 connect to the positive (or 12 volts) connection of the power supply. Alternatively all the units can be powered from a 16 volts AC supply. Install one train detector at the approach to the station at the position where it is required for the trains to start braking. Terminal "2" of this IRDOT-1 is connected to either terminal "D2" "D3" A OR "B" depending on the operation required. Wire from terminal "2" of the second (stopping) IRDOT-1 at B to terminal "D4" of the SA8.
If used with the SA6 and it is desired to have non stop goods trains wire from the "D3" terminal of the SA6 to terminal "D1" of the SA8. If reed switches are used instead of IRDOT-1 wire one end of each reed switch to the "o" terminal of the SA8 and wire the other end of the reed switch as described for terminal 2 of the IRDOT.
CONNECTIONS FROM IRDOT-1 OR REED SWITCHES
Diagram shows connection of IRDOT-1s for "stop every third lap"
Diagram shows connection of 2 reed switches for "stop every lap"
TRACK POWER CONNECTIONS
Separate connections are provided to power the control electronics and the track. This allows the choice of either powering everything from a 12 volt DC supply a 16volt AC supply or powering the track separately through a conventional controller. Using a controller in this way gives normal control outside the station with no sudden speed changes on crossing to the storage sidings. The controller setting governs the maximum speed the SA8 can accelerate trains to. Powering everything from a DC supply is more applicable to a completely automated system.
Everything powered from 12 volt DC supply
This is the simplest way to use the unit. Leave the wire link in place and connect the 12 volts D.C. supply as described previously. Note that the 12 volt supply must be a "smoothed" regulated supply.
The SA8 can be used as above to power a complete oval. If breaks are made in the both rails of the track both before the slow down IRDOT and a distance equal to the slowing down distance after the stop IRDOT (to allow for the train accelerating after leaving the station) this section can be fed by the SA8 and the rest of the oval by a normal controller. Another alternative if you wish to control the train manually sometimes is to insert a double pole switch so that either the SA8 or a controller can feed the oval.
TRAIN CONTROLLER
It is strongly recommended that you first get the SA8 working with the diode and capacitor as supplied before wiring in the controller. The wire link is removed. Either a 12 volt DC supply or a 16 volt AC supply is connected as described previously to power the control electronics and the IRDOT-1. The controller is connected to the SA8 unit. The track inside the isolation sections is powered from the SA8 track output. The controller will operate normally outside the isolated section. This section must be long enough for the braking and acceleration to be completed within the isolated track. Within this area the controller will be able to slow the train but not speed it up.
16 VOLT AC SUPPLY
The link is replaced with a diode with its band pointing in the direction shown. If smoothed DC is required the capacitor is also used. It must also be orientated as shown in the diagram. Smoothed DC prevents overheating of N scale motors. However some 00 gauge engines may run better with the half wave rectified DC which is supplied to the track when the capacitor is not used. Units are supplied in this form and will work with the diode and capacitor fitted when using a DC supply
CONNECTION TO THE SIGNAL (SA8-S ONLY):Relays on the SA board switch the signals. 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 signal can use the same power as the SA8-S or a separate supply. The diagram shows wiring common positive LED signals using the SA8-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. Bulb signals can also be used.
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 SA8-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.
Diagram on left shows common negative signal powered from a separate supply. Diode is only necessary if the supply is AC.
Diagram on the right shows bulb signals. Use of resitors depends on voltage of bulbs and voltage of power supply.
The signal is normally at red. On detecting a through train approaching the signal will change to green and return to red a few seconds after the train has passed through the station.
The signal is switched by a relay on the SA8-S. This allows power to be taken from either the same supply used for the SA8 or a separate signal supply. These relay contacts are shown in the diagram. Connections are shown to a relay signal. Bulb signals can also be operated. The resistor is only necessary for LED signals or limiting the voltage applied to bulb signals.
TESTING AND SET UP ADJUSTMENTS
This is best carried out in the following order.
Turn the variable resistors with a fine screwdriver to give delay time = short(turn clockwise), min speed = slow (turn clockwise), max speed = fast (turn anti clockwise), ACC/BR (rate of braking/acceleration)=abrupt(turn clockwise).
It may be found easiest to operate the unit so that it stops on each lap whilst making the adjustments. Regardless of its starting position the train will quickly accelerate to maximum speed after switching on power (green LED lit and SA8 signal at red). When the train is detected by the IRDOT-1 at the approach to the station it will rapidly reduce speed and halt (red LED lit on SA8). Adjust the min speed setting until the train just moves. It will then travel to the train detector at the end of the station and stop. The red and green LEDs will now flash alternatively for the delay time. At the end of which the signal will change to green. The red LED will light for a few seconds then on changing to the green LED lit the train will accelerate away. Adjust the maximum speed setting to the required speed (unless using the controller to determine the max speed in which case the maximum speed should be left at max). Each time the train brakes on approaching the station adjust the ACC/BR setting until the train slows to the minimum speed just before reaching the stopping position.
Note: min and max speed adjustments are confusing to set unless acc/brake is set to abrupt because of the effect of electronic inertia.
Finally adjust the delay time setting to the desired time. The length of the flashes is proportional to the delay time.
Overload protection
Overload protection is built into the SA8. If an excessive current is drawn from the unit then the overload circuit will prevent the unit from being damaged by switching off power to the track. This fault condition is indicated by the red and green LED's both lighting. As soon as the fault is rectified the unit will resume normal working.
INITIAL VARIABLE RESISTOR SET UP
Delay time = clockwise = min delay time
Acceleration (ACC/BR) = clockwise = fastest acceleration
MAX SPEED = anticlockwise = fastest speed
MIN SPEED = clockwise = slowest minimum speed
HEATHCOTE ELECTRONICS, 1 HAYDOCK CLOSE, CHEADLE, STAFFS, ST10 1UE
TEL/FAX 01538 756800 email cah:heathcote-electronics.co.uk
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