Timpdon Electronics
Tel: 0161 980 7804
Issue 1 — February 2018
www.timpdon.co.uk
Page 4 of 12
Notes on Wiring and Connections
1
Connect the servo via its 3 wire plug directly to the
GPRX7
Point
Servo
connector. Ensure that you observe the correct polarity.
2
Connect a d.c. supply to the
GPRX7
Power
connector. Ensure
that you observe the correct polarity. The supply voltage must be
between 4.8 V and 6 V nominal, to match the operating voltage
limits of standard servos.
The point system will only draw significant current while the servo
is in motion, so 4 x
AA
primary or rechargeable batteries are
perfectly adequate, and should give reasonable battery life.
You are recommended to switch off or disconnect the battery
supply when your layout is not in use, to avoid draining the
batteries unnecessarily.
3
Before use, the
GPRX7
must be
bound
to your transmitter, as
described above, allocated to a specific
point number
and
programmed for
servo rotation angles
. The calibration
procedure is described below.
Servo Mounting and Calibration
For optimum performance and ease of calibration you are strongly
recommended to follow the guidelines given here for servo mounting
and set up
.
Operating linkage at 90
degrees to straight track
Servo arm parallel
to straight track
Point Blades in
Mid Position
Timpdon Electronics
Tel: 0161 980 7804
Issue 1 — February 2018
www.timpdon.co.uk
Page 9 of 12
Auxiliary Outputs
Each auxiliary output is an active low voltage source, switching between
+5V [
High
] and 0V [
Low
], with a maximum current rating of 20 mA per
output.
Each auxiliary output can therefore drive
LED
s directly for colour light
signalling or, when used to trigger an external
Timpdon Electronics
ServoSwitch
, Model
SCS1
, will operate a servo controlled semaphore
signal arm.
Auxiliary Output Wiring Diagrams
Colour Light Signals
Green Clear signal only on each Auxiliary Output
Green Clear signal and Red Danger signal on
Each Auxiliary Output
Each
LED
requires a current limiting resistor in series. A value of
470 ohm will give a
LED
current of about 5 mA, for both
Red
and
Green LED
s, adequate for most applications.
