User's Manual

ManualsBrandsGraupner ManualsElectronicsComputerSystem Graupner HoTT

100

112

Program description: servo settings

possible it is always best to maintain your programmed

settings using the SMART-BOX.

Switch your receiving system on. Move the mode switch

in position „normal“. Locate the BIND-button on the front

of the transmitter, and hold it pressed in while you switch

the transmitter on.

Release the button again once it is switched on.

You can now call up the desired Fail-Safe mode (Fail-

Safe on / off, Hold, or Standard) by cycling through the

modes with a brief press of the BIND-button:

Fail-Safe mode: •

when you press the BIND-button, the transmitter beeps

once; the Status-LED ﬂ ashes green and orange alter-

nately. It is now possible to program positions to which

the servos will move in a Fail-Safe situation; this occurs

after a “Hold” period of 0.75 seconds: move the corre-

sponding transmitter controls to the desired Fail-Safe

positions SIMULTANEOUSLY, then hold the BIND-button

pressed in for three to four seconds. When you release

the button, the orange LED should light up constantly,

and the transmitter should not emit an audible signal:

the transmitter now reverts to Control mode. If this does

not occur, repeat the procedure.

Hold mode (recommended for model helicop-•

ters):

Factory default setting. When you press the BIND /

RANGE button, the transmitter beeps twice; the Status-

LED ﬂ ashes green and 2-times orange alternately. If

interference occurs, all servos programmed to “Hold”

remain at the last position detected by the receiver as

correct; this situation is maintained until such time as

the receiver picks up a new, valid control signal. You can

save your selection by holding the BIND-button pressed

in for three to four seconds. When you release the

button, the orange LED should light up constantly, and

the transmitter should not emit an audible signal: the

transmitter now reverts to Control mode. If this does not

occur, repeat the procedure.

Fail-Safe OFF: •

when you press the BIND-button, the transmitter beeps

three times; the Status-LED ﬂ ashes green and 3-times

orange alternately. You can save your selection by

holding the BIND-button pressed in for three to four

seconds. When you release the button, the orange LED

should light up constantly, and the transmitter should

not emit an audible signal: the transmitter now reverts

to Control mode. If this does not occur, repeat the

procedure.

Standard mode (suitable for ﬁ xed-wing model •

aircraft only):

when you press the BIND-button, the transmitter beeps

four times; the Status-LED ﬂ ashes green and 4-times

orange alternately. In this mode the throttle servo (chan-

nel 1) moves to the Fail-Safe position, i.e. the position

you have programmed for a Fail-Safe situation, while all

the other channels remain at “Hold”. Move the throttle

stick to the desired position, then hold the BIND-button

pressed in for three to four seconds. When you release

the button, the orange LED should light up constantly,

and the transmitter should not emit an audible signal:

the transmitter now reverts to Control mode. If this does

not occur, repeat the procedure.

Note:

With the optional Smart-Box Fail Safe can also be pro-

grammed separately for each channel. See the section

„telemetry“ on page 113.

Installation Notes

Receiving system power supply

A reliable power supply is one of the basic essentials for

reliable model control. Free-moving pushrods, a fully-

charged battery, battery connecting leads of adequate

cross-section, minimal transfer resistance at the connec-

tors etc. all help to minimise energy consumption, but if

you have attended to all this, and the receiver voltage

displayed on the transmitter screen still collapses

repeatedly, or is generally (too) low, then please note the

following:

The ﬁ rst point to check is that your batteries are always

fully charged at the start of each ﬂ ying session. Check

that contacts and switches are low in resistance. It is a

good idea to measure the voltage drop over the installed

switch harness under load, as even a new, heavy-duty

switch can cause a voltage drop of up to 0.2 Volt. Ageing

effects and oxidation of the contacts can increase this

several times over. Constant vibration and movement

at the contacts also “gnaws away” at the contacts, and

tends to produce a creeping increase in transfer resis-

tance.

It is also true that even small servos, such as the Graup-

ner/JR DS-281, can draw currents of up to 0.75 Ampere

when stalled (mechanically obstructed). Just four servos

of this type in a “foamy” can therefore place a load of up

to 3 Amps on the airborne power supply ...

For this reason you should always choose a receiver

battery which constantly delivers an adequate voltage,

i. e. which does not collapse under severe load. To “cal-

culate” the necessary battery capacity we recommend

as a starting point that you provide 350 mAh for each

analogue servo, and at least 500 mAh for each digital

servo.

For example, a 1400 mAh battery would represent an

absolute minimum as the power supply for a receiving

system with a total of four analogue servos. When ma-

king your calculations, however, please bear the receiver

in mind as well, as it draws a current of around 70 mA

due to its bi-directional function.

Regardless of these considerations, it is generally

advisable to connect the power supply to the receiver

using two leads. For example, you could use a switch or

voltage regulator with two power supply leads running

to the receiver. You might install a Y-lead, Order No.

3936.11, between lead and receiver, as shown in the

diagram below, if you wish to use one or both of the

receiver sockets to connect a servo, speed controller,

etc. The dual connection at the switch or voltage regu-

lator not only reduces the risk of a cable fracture, but

also ensures a more even energy supply to the servos

connected to the receiver.

Auxiliary function

Y-lead,

Order No. 3936.11

PRX stabilised

receiver power supply,

Order No. 4136

Four-cell Ni-MH battery packs

Traditional four-cell packs are a good choice for pow-

ering your Graupner HoTT receiving system, provided

that you observe the conditions described above, i. e.

you must ensure that the packs have adequate capacity

and maintain their voltage well.

Five-cell NiMH battery packs

Five-cell batteries offer a wider margin of safety in terms

of voltage compared with four-cell packs. However,

please note that not all servos available on the market

can tolerate the voltage of a ﬁ ve-cell pack (in the long-

term), especially when the battery is freshly charged.

For example, many of these servos respond to the high

voltage with a clearly audible “rumble”.

It is therefore important to check the speciﬁ cation of the

servos you intend to use before you make the decision

to use ﬁ ve-cell packs.

Two-cell Nanophosphate® (A123) batteries

Taking into account the current situation, these new cells

are now regarded as the optimum choice for receiver

packs. A123 cells can be fast-charged in conjunction

with a suitable battery charger, and are protected by a

metal case and therefore comparatively robust. It is also

true that a much higher number of charge / discharge

cycles is attributed to this cell type than, for example,

to LiPo cells. The nominal voltage of 6.6 Volt of a two-

cell Nanophosphate® pack presents no problems to

Graupner HoTT receivers, nor to those servos, speed

controllers, gyros, etc. which are expressly approved for

use at these higher voltages. Please note, however,

that virtually all servos, speed controllers, gyros etc.

sold in the past, and also most of those currently

available, are only approved for use on an operating

voltage in the range 4.8 to 6 Volt. If you wish to con-

nect these devices to the receiver, it is essential to use

a stabilised regulated power supply, such as the PRX,

Order No. 4136; see Appendix. If you neglect this, there

is a danger that the connected devices will quickly suffer

permanent damage

Two-cell LiPo battery packs

For a given capacity LiPo batteries are a great deal ligh-

ter than the battery types described above, but they are

more susceptible to mechanical stress and damage due

to their lack of a metal case. Moreover LiPo batteries

only have a limited ability to be fast-charged, and

33110_mx10_HoTT_1_DE.indd Druckbogen 97 von 104 - Seiten (112, 97)

21.10.2011 13:25:41