UAV Factory GPU, 100 W GENERATOR POWER UNIT User Manual

UAV Factory USA LLC.

50 South Buckhout Street,
Irvington, NY 10533 USA
Phone: [phone]
Fax: [phone]
Email: [e-mail]

UAV Factory LTD. EUROPE

24A-52 Ganibu Dambis,
LV1005, Latvia
Phone: [phone]
Fax: [phone]
Email: [e-mail]

100 W GENERATOR POWER UNIT

USER MANUAL 1.5

1

UAV Factory USA LLC.

50 South Buckhout Street,
Irvington, NY 10533 USA
Phone: [phone]
Fax: [phone]
Email: [e-mail]

UAV Factory LTD. EUROPE

24A-52 Ganibu Dambis,
LV1005, Latvia
Phone: [phone]
Fax: [phone]
Email: [e-mail]

1. Description

100 W Generator Power Unit (GPU) is designed to provide onboard dual voltage regulated power supply for the
unmanned aircraft vehicles.

Despite small size, power unit offers outstanding efficiency as well as unique features such as the ability to monitor load,
battery current, engine rpm, generator and battery voltage through TTL serial communication. All power distribution
parameters can be transmitted to the ground station and monitored during the flight.

Generator power unit can be used with brushless or brushed generators that have a voltage output within 10-35 Volts
and 13-50 Volts respectively. Integrated Lithium Polymer charger is used for the backup battery, which is switched on
during the pre-flight checks, power peaks, or in the event of the engine failure.

Power unit is packed in a sealed aluminum enclosure and fitted with the high-end industrial push-pull connectors. Fan
assisted cooling option is available.

Please contact for customized solutions.

2. Key Features

 Light weight, small and efficient
 13 V to 50 V input range
 100 W continuous load
 Compatible with brushed or brushless

generators

 6 V and 12 V output
 Load current up to 10 A
 Short circuit protection
 Battery backup connection
 3 cell Li-Poly integrated charger
 External power connection
 Integrated current sensors
 TTL connection
 IP 64 housing, IP 68 on request

2

UAV Factory USA LLC.

50 South Buckhout Street,
Irvington, NY 10533 USA
Phone: [phone]
Fax: [phone]
Email: [e-mail]

UAV Factory LTD. EUROPE

24A-52 Ganibu Dambis,
LV1005, Latvia
Phone: [phone]
Fax: [phone]
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1

Enclosure temperature must not exceed 70 °C, additional cooling may be required

2

The tachometer range is valid for serial number starting from GPU0042

Electrical Specifications

Brushed generator voltage range
Brushless generator voltage range

13 – 50 V
10 – 35 V

External power supply voltage range

13 – 50 V

Battery Type

3 cells, Lithium Polymer

Battery Voltage

12.6 V

Maximum battery charging current

2 A

Maximum continuous generator input current

8 A

Maximum continuous battery input current

8 A

Maximum continuous external power current

8 A

Output voltage

6 V and 12 V

Maximum output voltage ripple

200 mV@6V 400mV@12V

Continuous load current, 6 Volt output1

5A

Continuous load current, 12 Volt output1

5A

Maximum peak load current

10 A for 10 seconds

Efficiency of 6 Volt output

85% typical

Efficiency of 12 Volt output

90% typical

No load GPU current

110 mA

Tachometer range2

1000-90000 rpm

Tachometer accuracy

200 rpm

Current sensor range

0 to 10 A

Current sensor accuracy

0.2 A

Voltage sensor accuracy

0.1 V

Serial Communication

5V TTL

Mechanical Specifications

Dimensions

59.4 x 115.8 x 32.4 mm

Weight ( with conductive enclosure)

190 grams

Cooling method

Conductive or fan-assisted

Maximum enclosure temperature

70°C

Environmental protection

IP 64 standard, IP 68 on request

Operating temperature

- 40°C to +50°C 1

Electrical connectors

Fischer 104 Series push-pull connector

3

UAV Factory USA LLC.

50 South Buckhout Street,
Irvington, NY 10533 USA
Phone: [phone]
Fax: [phone]
Email: [e-mail]

UAV Factory LTD. EUROPE

24A-52 Ganibu Dambis,
LV1005, Latvia
Phone: [phone]
Fax: [phone]
Email: [e-mail]

4

UAV Factory USA LLC.

50 South Buckhout Street,
Irvington, NY 10533 USA
Phone: [phone]
Fax: [phone]
Email: [e-mail]

UAV Factory LTD. EUROPE

24A-52 Ganibu Dambis,
LV1005, Latvia
Phone: [phone]
Fax: [phone]
Email: [e-mail]

Load current 5 A

3. Performance

The GPU performance graphs are presented below. Efficiency for the 6 V output against the input voltage is shown in
Figure 1, efficiency for 12 V output is shown in Figure 2.

The maximum continuous power of the GPU is dependent on the ambient temperature and the ability to dissipate heat
generated by the GPU. The maximum continuous power to ambient temperature relation is shown in Figure 3. At no
circumstances operating GPU enclosure temperature should reach 70° C.

Figure 1 Efficiency at 6 Volt output vs input voltage

5

UAV Factory USA LLC.

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UAV Factory LTD. EUROPE

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Load current 5 A

Figure 2 Efficiency at 12 Volt output vs input voltage

Figure 3 Allowable continuous power depending on ambient temperature

6

UAV Factory USA LLC.

50 South Buckhout Street,
Irvington, NY 10533 USA
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Fax: [phone]
Email: [e-mail]

UAV Factory LTD. EUROPE

24A-52 Ganibu Dambis,
LV1005, Latvia
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G

GPU

Brushed

generator

DC-DC

converter

J2

connector

G

GPU

Brushless

generator

DC-DC

converter

J2

connector

a

b

c

4. Generator

GPU is available in brushed or brushless versions. In the brushed GPU version, the brushed generator’s voltage output
must be within 13-50 V range. If the voltage out is below 13 V, GPU will automatically switch to battery source.

In the brushless GPU version, the 3-phase rectifier is used between the generator and the internal DC-DC converter of
the GPU (refer to Figure 5). Therefore DC voltage at the DC-DC converter is equal to rectified value of generator’s AC
voltage. In this case generator’s line voltage RMS value must be within 10 - 35V range. Line voltage RMS value can be
measured between any two leads of the generator. If the voltage out is below 10 V, GPU will automatically switch to
battery source

Figure 4 Brushed generator and GPU internal connection

Figure 5 Brushless generator and GPU internal connection

7

UAV Factory USA LLC.

50 South Buckhout Street,
Irvington, NY 10533 USA
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Fax: [phone]
Email: [e-mail]

UAV Factory LTD. EUROPE

24A-52 Ganibu Dambis,
LV1005, Latvia
Phone: [phone]
Fax: [phone]
Email: [e-mail]

GPU can be used for both - brushed and brushless generators. Please state the required generator type in your order.
The typical connection diagram for the brushless and brushed generator systems is shown in Figure 7 and Figure 8
respectively.

GPU can be used both with inline generators and geared generators. An example of a belt-driven generator is shown in
Figure 6. The ratio between the pulleys is chosen to keep the GPU input voltage under the 50 V limit

Figure 6 Belt-driven onboard generator example

In many cases, at low engine rpm, the voltage generated is less than 13 V, which means that the onboard battery will be
used for powering the unmanned aircraft systems. This is not an issue, since aircraft do not generally fly at low idle
settings for extended periods of time and the power requirements can be met by the onboard battery. The onboard
battery capacity needs to be calculated depending on actual mission profile of the UAV, taking into account possible
aircraft descend time as well as desired pre-flight operation time- please see section 10 for more details and battery
capacity estimation formula. Please use adequate safety factor for your battery capacity estimation results.

8

UAV Factory USA LLC.

50 South Buckhout Street,
Irvington, NY 10533 USA
Phone: [phone]
Fax: [phone]
Email: [e-mail]

UAV Factory LTD. EUROPE

24A-52 Ganibu Dambis,
LV1005, Latvia
Phone: [phone]
Fax: [phone]
Email: [e-mail]

GPU

Generator

Battery

6 V load

12 V load

Transmitter

Battery +

GND

Brushed gen +

Ext. power +

GND

+

-

GND

+ 6 V out

+ 12 V out

GND

Serial GND

Serial Tx

RPM sensor

RPM sensor

GND

External power

connector

Generator GND

+

-

GPU

Generator

Battery

6 V load

12 V load

Transmitter

Battery +

GND

Brushless
generator

Ext. power +

GND

+

-

GND

+ 6 V out

+ 12 V out

GND

Serial GND

Serial Tx

RPM sensor

RPM sensor

GND

External power

connector

Figure 7 Typical connection diagram for brushless generator

Figure 8 Typical connection diagram for brushed generator

9

UAV Factory USA LLC.

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Irvington, NY 10533 USA
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UAV Factory LTD. EUROPE

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LV1005, Latvia
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Load 1

Load 2

Load 3

Fuse

Fuse

Fuse

Figure 9 Installation of the fuse before each load will allow the GPU to supply power in case of the load short-circuit

5. Short circuit protection

The GPU has integrated short circuit protection for avoiding the regulator damage in case of a short circuit.

In case multiple loads are used on the same voltage line it is highly recommended to use fuses- this will allow the GPU to
operate in the event of load short circuit. Please see Figure 9 for a diagram of fuse installation.

As an example, fuses can be installed before the payload, rf-transmitters as well as before the individual servos. If, for
instance, there is a short-circuit in the payload - unmanned aircraft can still perform a safe landing.

6. Battery backup

External battery provides power supply to the system in case the input voltage drops below the battery voltage. This
may occur because of several reasons:

a) During engine idle, when generator provides insufficient voltage at the given load

b) During pre-flight preparation when the engine is not operating and the external power supply is not
connected

c) During mechanical generator failure

d) During engine failure

The following formula should be used to calculate approximate battery capacity for a particular UAV configuration:

Battery capacity (Ah) = operation time (h)  average load power (W) / battery voltage (V) / 0.8

Where operation time is desired operation time, battery voltage is 11.1 V and 0.8 is regulator typical efficiency.

10

UAV Factory USA LLC.

50 South Buckhout Street,
Irvington, NY 10533 USA
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UAV Factory LTD. EUROPE

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6 Volt output

12 Volt output

Do not use other type of battery except Lithium Polymer 3 cell battery. Maximum battery current should not exceed 8
A. When battery voltage is less than 12.6 V the charger charges the battery with current of <2 A. It is recommended to
connect battery to the system through the switch with current rating not less than 10 A.

When the battery source is used, GPU is not producing exactly 12 volt power output, please see Figure 10 for details.
The battery voltage and output voltage difference is approximately 0.4V and GPU cannot provide 12 V voltage if battery
voltage is less than 12.4 V and starts to operate with 100 % duty cycle.

Figure 10 Output voltage in battery source mode

7. External Power Supply

External power supply can be used as a power source when the engine is no operating. This is especially useful for
laboratory environment testing, during set-ups, during pre-flight checks on field as well as for charging the onboard
battery. The input voltage range should be in range of 13-50 Volts.

8. Connector Description

GPU enclosure has two electrical connectors - J1 and J2, as seen on Figure 11. Pinout of J1 connector is shown in Figure
12 and is the same for both, brushed and brushless GPU configurations.

Please note, pinout of J2 connector is different for brushless and brushed GPU configurations. Figure 13 shows pinout
configuration for brushless GPU option and Figure 14 shows pinout configuration for brushed GPU option.

11

UAV Factory USA LLC.

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Irvington, NY 10533 USA
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UAV Factory LTD. EUROPE

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LV1005, Latvia
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Red mark

RPM sensor

Battery +

GND

GND

External power +

Brushless generator

Red mark

+ 12 V out

+ 6 V out

GND

Serial Tx

Serial GND

Figure 13 Connector J2 description (for brushless generator)

Figure 11 Input, Output connectors and status LEDs

Figure 12 Connector J1 description

12

UAV Factory USA LLC.

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Irvington, NY 10533 USA
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UAV Factory LTD. EUROPE

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Red mark

RPM sensor

Battery +

GND

Generator
GND

External power +

Brushed generator +

Figure 14 Connector J2 description (for brushed generator)

9. LED Indication

Four indication LEDs are located on the front side of the GPU, see Figure 11 for reference. The main purpose of LEDs is to
facilitate set-up procedure, simplify pre-flight checks as well as to provide clear identification of the battery status
before the flight. The following LED operation is implemented in the GPU:

6 V – green LED indicates 6 V voltage presence.

12 V – green LED indicates 12 V voltage presence.

BAT – green LED indicates that battery is supplying the system. When LED is off the generator or external power is

supplying the system.

CHRG – red LED indicates battery charging. When LED is flashing the battery voltage is low and the generator provides
not enough power.

10. Tachometer

Tachometer input allows to monitor engine or generator rotation speed using engine ignition system hall sensor. This
reading can be sent through TTL port to autopilot and transmitted to the UAV ground station via the rf-link.

Connect signal output to RPM sensor input and ground pin to common ground of the power unit - see Figure 13 and
Figure 14 for details.

13

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Fax: [phone]
Email: [e-mail]

UAV Factory LTD. EUROPE

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LV1005, Latvia
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11. Serial communication

Serial communication allows to monitor system variables such as: generator and battery voltage, battery and load
currents, total system power and RPM value.

Serial protocol uses 83 bytes packet and send it one per second, Figure 15 shows the output string format. This protocol
is valid for GPU serial number starting from GPU0042. For older serial number, refer to the user manual version 1.4.
Variables are separated with 3 spaces. The output string example is:

Rpm=3400 Vgen=27.3 Vbatt=11.82 Ibatt=-1.3 I6v=1.2 I12v=0.8 Pout=16

Rpm – rpm value

Vlin – internal line voltage

Vbatt – battery voltage

Ibatt – battery current (negative value for charging)

I6v – load current at 6 V line

I12v – load current at 12 V line

Pout – total output power

Serial communication settings:

Baud rate 9600

Bits 8

No parity

14

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B00

B01

B02

B03

B04

B05

B06

B07

B08

B09

B10

B11

B12

B13

B14

B15

B16

B17

R p m =

space

space

space

V g e n =

B18

B19

B20

B21

B22

B23

B24

B25

B26

B27

B28

B29

B30

B31

B32

B33

B34

space

space

space

V b a t t =

B35

B36

B37

B38

B39

B40

B41

B42

B43

B44

B45

B46

B47

B48

B49

B50

B51

space

space

space

I b a t t =

space

space

space

B52

B53

B54

B55

B56

B57

B58

B59

B60

B61

B62

B63

B64

B65

B66

B67

B68

I 6 v =

space

space

space

I 1 2 v =

B69

B70

B71

B72

B73

B74

B75

B76

B77

B78

B79

B80

B81

B82

space

space

space

P o u t = /r

/n

Figure 15 Output string format

15

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J2

J1

Ignition

Serial

12Vout

6Vout

GEN

RPM Input

EXT

BATT

Label

Wire color

Connection description

GEN
red

Brushless generator phase A

red

Brushless generator phase B

red

Brushless generator phase C

GEN
red

Brushed generator “+” lead

black

Brushed generator “–” lead

Ignition
red

Power output for ignition module (6V)

black

Power ground for ignition module (GND)

RPM input
orange

RPM sensor input (Signal)

black

RPM sensor ground (GND )

Serial
green

Serial interface output (Tx)

black

Serial interface ground (GND)

BATT
red

Battery power input (3 Cell LiPo)

black

Battery power ground (GND)

EXT
red

External power supply input (13-50V)

black

External power ground GND)

6Vout
red

6V power output (6.0V)

black

6V power ground (GND)

12Vout
red

12V power output (12.0V)

black

12V power ground (GND)

12. Cable set with plug for J1 and J2 wiring

Cable set with plug for J1 and J2 can be optionally ordered from UAV Factory. Figure 16 shows cable set schematic
diagram for J1 and J2. Cable set is labeled to specify connection of each wire. For description of connections please refer
to Table 1.

Figure 16 Cable set wiring schematic diagram

Table 1 Cable set description of connections

16

UAV Factory USA LLC.

50 South Buckhout Street,
Irvington, NY 10533 USA
Phone: [phone]
Fax: [phone]
Email: [e-mail]

UAV Factory LTD. EUROPE

24A-52 Ganibu Dambis,
LV1005, Latvia
Phone: [phone]
Fax: [phone]
Email: [e-mail]

13. Order Information

GPU Accessories

Item

Order code

Qty

FISCHER cable plug for J1

S104A056

1

FISCHER cable plug for J2

S104Z056

1

Cable set with plug for J1, 50 cm

SJ105

1

Cable set with plug for J2, 50 cm

SJ205

1

Cable set with plug for J1, 100 cm

SJ110

1

Cable set with plug for J2, 100 cm

SJ210

1

Version

Comments, Updates

Date

Author

1.4

Voltage range is added for BLDC generator
in electrical specification

5/15/2012

AG

1.5

Tachometer range is extended to 90000
rpm

2/11/2013

AG

Brushed version GPU100

Brushless version GPU100B

14. User manual version history

17