PowerBox Systems P2-SERVOBRIDGE User manual

INSTRUCTION MANUAL
P2-ServoBridge

2PowerBox-Systems − World Leaders in RC Power Supply Systems
Dear Customer,
we are delighted that you have chosen the P² ServoBridge from PowerBox-Sys-
tems.
The P²-ServoBridge is a multi-function adapter for connecting conventional PWM
servos to various bus systems, featuring an adjustable electronic fuse. The P²-Ser-
voBridge can also be used as an over-current power-off device at normal receiver
outputs with a PWM signal.
When used in conjunction with PowerBox, Jeti or Futaba radio control systems the
P²-ServoBridge transfers telemetry data such as voltage, current and temperature
to the transmitter. Additional data, including peak current or average current, are
helpful in optimising the adjustable fuse.
When used with the PowerBox Core and Atom, and also with Jeti radio control
systems, all the device’s parameters can be adjusted from the transmitter; with all
other systems adjustments are carried out using the Royal SR2 and Competition
SR2. A further adjustment facility is available using the PC-Terminal program and
a USB adapter.
Our website includes a range of factory-made cables and distributors for the wiring
in your model; they are available in various sizes and conductor cross-sections.
For wiring in the model you will nd pre-assembled cables and distributors in vari-
ous sizes and cross-sections on our website.
We wish you much pleasure and success with the PowerBox P²-ServoBridge!

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Features:
Automatic detection of the bus system in use
Can be used with P²-BUS, S.BUS2, SRXL/UDI or PWM
Telemetry data for PowerBox, Jeti and Futaba radio control systems
Current, voltage and temperature acquired at the servo itself
Adjustable at the transmitter with PowerBox and Jeti radio control systems
Unrestricted choice of bus channel
Variable PWM frame rate: 12ms, 14ms, 16ms and 18ms
Accurately adjustable electronic fuse
Automatic fuse reset function
Facility to set two separate cut-off currents and times
Fuse immune to wear or ageing effects
Fuse not temperature-dependent
LED display of power-off processes
Can be updated via USB interface
Compact design: 35mm x 12mm x 4mm
Low weight: 4g

4PowerBox-Systems − World Leaders in RC Power Supply Systems
1. INSTALLATION
The most efcient way of mounting the P²-ServoBridge is to attach it to a metal
surface on the servo. As this ensures optimum temperature measurement.
To transfer the temperature of the servo case to the sensor of the P²-ServoBridge,
apply a small amount of heat-conducting paste to the hole in the sensor as shown
in the illustration (1), then wipe it off ush.
Remove the backing lm from the adhesive tape once you have done this (2).
1 2

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3 4
Stick the P²-ServoBridge to the underside or one side of the servo, to suit the
installation in your model (3).
Now connect the output of the ServoBridge to the servo input socket (4).
To minimise losses between the P²-ServoBridge and the servo we recommend
that you shorten the servo cable and crimp a new connector (Order No. 1060) to
the end.

6PowerBox-Systems − World Leaders in RC Power Supply Systems
2. SET-UP
The P²-ServoBridge operates with a range of bus systems as well as standard
PWM servo signals. All signals are detected automatically, which means that the
device is ready to use immediately. The default settings are: Channel 1, fuse set
for servos rated at 15kg/cm to 25kg/cm output torque. The following adjustment
facilities are available at your transmitter or in PC-Terminal:
2.1 OUTPUT CHANNEL
At this point you can select the channel to be derived from the bus signal: this will
be generated as a PWM servo signal.
2.2 FRAME RATE
The frame rate refers to the speed at which the PWM signal is repeated at the
ServoBridge’s output. Modern digital servos generally operate without problem at
the 12ms setting, but the frame rate should be set to the slower 18ms value for use
with earlier analogue servos. If in doubt, your servo manufacturer will be able to
provide accurate information.
2.3 SERVO TYPE
Four different pre-set servo templates can be selected at the P²-ServoBridge:
Micro, Midi, Standard and Hi-Torque. Of course, you can also adjust the set values
for the two fuse thresholds individually if you wish.

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The table below is designed to help you assign your servo to the appropriate
category:
Servo type Servo size in mm Output torque in kg/cm
Micro 8 – 12 2 – 7
Midi 12 - 15 8 – 15
Standard 20 15 - 25
Hi-Torque 20 25 - 60
2.4 TRIP CURRENT AND TRIP TIME
The P²-ServoBridge has two current thresholds which can be set to different valu-
es, as well as the associated trip time.
This feature enables you to set one threshold which causes the fuse to trip if the
current value is exceeded for a signicant period. The second threshold then swit-
ches the power off if a higher current peak of shorter duration occurs.
An example:
Trip current 1: 5.0A
Trip time 1: 2000ms
Trip current 2: 8.0A
Trip time 2: 500ms
The fuse switches the power off if a current of 5.0A is exceeded for at least two
seconds, and also if 8.0A is exceeded for half a second.
If you don’t wish to set two different threshold values, simply set both trip currents
and times to the same value.

8PowerBox-Systems − World Leaders in RC Power Supply Systems
3. FUSE FUNCTION, RESET FUNCTION
The electronic fuse is very precise in operation, and can be set accurately to suit
any application. In contrast to the commonly used polyfuses, the power-off current
does not vary with external temperature. The cut-off characteristics of electronic
fuses do not vary even if used frequently, i.e. the device continues to work reliably
even over a period of years.
A further advantage of electronic fuses is that it is possible to set two different
cut-off thresholds, as mentioned above. Excessive continuous current can damage
a servo just as easily as a brief period of higher (peak) current - for example, as a
result of overheating. Electronic fuses are able to cope with both scenarios.
The automatic Reset function attempts to restart the consumer unit (servo) after
it has been switched off. This is accomplished by switching the fuse on again,
and measuring the current. If the current is above half the set thresholds, the fuse
immediately switches off again. This procedure is repeated ten times at interva-
ls of one second before the fuse switches off permanently. The frequency of the
power-off actions is indicated by the ashing LED.
4. LED FUNCTIONS
The two-colour LED can display various operational states:
LED constant blue: bus system detected, fuse on. No power-off events.
LED ashing blue: bus system detected, fuse on, number of ashes indicates
number of power-off events.
LED ashing red: bus system detected, fuse off, number of ashes indica-
tes number of power-off events. The automatic reset function was unable to
restart the consumer unit within the set parameters.
LED ashing violet: no bus system detected: the P²-ServoBridge is in Terminal
USB mode.

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5. BUS-OPERATION, P²-SERVOBRIDGE SET-UP FACILITIES
Various methods can be employed to set up and adjust the P²-ServoBridge.
A greater or lesser quantity of data can be transferred depending on the bus system
in use. Several systems allow the P²-ServoBridge to be set up from the transmitter.
The table below provides an overview of the integral functions:
Radio control system
Application Telemetry Servo bus Set-up
PowerBox P²-BUS
Current, voltage, capacity,
temperature, peak and
average current, status
Radial and parallel
addressed telemetry
26 channels
At the transmitter
itself
Royal SR2
Competition SR 2
Full servo telemetry only
in conjunction with Core
and Atom
P²-BUS
Radial and parallel
addressed telemetry
26 channels
At the PowerBox
Data socket via the
P²-BUS menu
Jeti EX-Bus
Current, voltage, capacity,
temperature, peak and
average current
One Bridge per EX-BUS
output
24 channels
At the transmitter
itself
Futaba S.BUS 2 Current, voltage, capacity,
temperature
Radial and parallel
addressed telemetry
Max. 7 Bridges,
16+2 channels
USB interface and
PC-Terminal
SRXL/UDI None Radial
16 channels
USB interface and
PC-Terminal
PWM Servo signal None None USB interface and
PC-Terminal

10 PowerBox-Systems − World Leaders in RC Power Supply Systems
5.1 IN CONJUNCTION WITH POWERBOX CORE AND ATOM TRANSMITTERS
WITH P²-BUS
If you wish to adjust the P²-ServoBridge using a PowerBox transmitter, connect
the unit to the P²-BUS socket at the receiver or the PowerBox Royal SR2, and carry
out a Rescan.
If multiple P²-ServoBridges are installed in the model, the address should imme-
diately be established. The transmitter automatically sets the address to a vacant
location when you press the X->Y button.
!
NOTE
The sensor address is not the channel address! The transmitter automatically
sets the sensor address for telemetry. You must use settings to dene the chan-
nel on which the P²-ServoBridge output is to be generated. In theory it is possible
to connect a maximum of 250 ServoBridges to the P²-BUS, but output is limited
to channels 1- 26!
The P²-ServoBridge now appears in the list as a sensor, and from here you can
access the menu in order to enter your preferred settings.
Any additional ServoBridges should be connected in the same manner.