olnico

Hello.

I would like to share my experience about this new product from Powerbox and compare it with the previous one.
I want also to share my test protocoles. I've seen very few people doing the kind of test I'm going to describe below. It is a real shame because it is really helpfull to assess the correct configuration for the electrical power supply system and to detect a potential problem/hazard ( system under-size, servo over-consumption, connection problem, hinge or control surface problem... )

First of all I've been testing both Sensor II and Sensor I switches in very difficult conditions.
This units have been torture-tested in extreme heat conditions under various loads.
I've then extensively flown them on my AD Phoenix.

I've come to the conclusion that this system is perfect for small size jets ( 6-7 kgs / 10-15 lbs thrust class ).
It will do the job flawless powering 7 micro/mini flight control digital servo + 3-4 std servos / valves.

My Phoenix setup is the following:

2 Lipo 2s1p 1000 mAh receiver batteries
1 Spektrum AR9000 receiver + 2 remote antennas + flightlog
1 Sensor switch
7 JR DS 368 mini digital servos for the flight controls
1 JR S 537 for the nose gear
2 Jettronics valves for the LG and brakes
P60 and standard loom

After 4 flights the batteries are typically 7,40 to 7,45 V.

Lets come back to the new Sensor II.

Here is the box:



The "2,4 G ready" logo is there to let us know that Powerbox has tested the product with all major spread spectrum providers systems ( Futaba, XPS, Spektrum ) and has not found any compatibility problem.

Here is the device compared to the previous version.



The only noticeable external differences are the coloured LEDs.
The old version had green external LEDs, the new one has multicolor LEDs.
Note that I have drawn a separation on the picture between "side 1" and "side 2". It is really interresting and important to do a mark on the cables and switch panel since it will tell you what side is getting week.
Then you'll know what battery has a problem/ what side draws more current.
It is one of the cons I'd put on this product: it has two fully seperated circuitries and indications but no marking on the LEDs/cables !

And from the back:



Powerbox has introduced a blue heat sink on the new version.
This may look fancy but well see later that it is a drawback.

Here is the major difference between the two versions: the Sensor II will tell you what voltage is present upstream the switch ( for both sides ).
You can also recall the lowest voltage recorded since the last shutdown. This is really usefull.

On Lipos, the LEDS will show this:
Green: 7,2 V and more
Orange: 6,9-7,2 V
Red: 6,7-6,9 V
Blinking red: lower than 6,9 V

On NiMhs/ NiCds, the LEDS will show this:
Green: 6,0 V and more
Orange: 5,9-6,0 V
Red: 5,7-5,9 V
Blinking red: lower than 5,7 V

Here is what you'll get with 6,5V on side II ( red blinking ) and 6,8 V on side I ( red steady )



Now lets talk about the torture-test:

The plane described above has been statically tested for several hoursat very high OAT and reallistic load.
The purpose of this test is to see if the switch will handle the heat. The limiting element on this device is the heat sink.
The IC board can handle quite a lot of heat, but if the heat sink reaches 150°c, the system WILL go to a thermal runaway and fail.
Powerpox recomends a maximum heat sink temperature of 100°c. Depending on the OAT, the plane can handle various loads.
At 20°c the switch can easily handle 5 A of current ( 2 times 2,5 ). So what about very hot conditions ?

Meteo conditions:

OAT 40°c, 25% humidity, full sunshine in Dubai

Plane sitting on the tarmac, canopy temp=50°c, aircraft skin temp=45°c.

Load: 200g of lest on each aileron
400g of lest on the elevator

Radio on servo test: ALL chanels moving to end stops.

The electrical load is checked with the excellent Hangar9 volt/amp digital meter.
The heat sink temperature is checked with an infrared thermometer.

Here is the test setup before going to the field.



Average total load in this condition: 1,85 A
Peak load: 2,5 A
Min load: 0,7 A

Here are the data recorded with the Sensor II

Initial heat sink temp ( idle activity ): 63°c
Heat sink temp after 1 minute : 71°c
Heat sink temp after 12 min : 95°c
Heat sink temp after 1 h 20 min : 95°c

Here are the data recorded with the previous Sensor version:

Initial heat sink temp ( idle activity ): 60°c
Heat sink temp after 1 minute : 69°c
Heat sink temp after 15 min : 85°c
Heat sink temp after 1 h 30 min : 85°c

So first thing: the switch is working without any problem on both versions with this plane setup.
The heat sink stabilises after a very short while ( 2 minutes ). In this case there is no thermal runaway whatsoever.
The heat sink gets VERY hot: do not touch, do not install in remote/ confined locations. Best prefer a ventilated area.
Note that even if the switch is not installed in a ventilated area, it is fine ( in the test case it had to dissipate the heat without any ventilation ).
The new version with the blue heat sink gets hotter. Obviously black is best for heat dissipation.

Now lets look at the flight data:

After 4 flights of 15 minutes each the batteries are typically 7,40 to 7,45 V. I do not go beoynd this point to keep a reasonable safety margin.
The heat sink does not go hotter than 75°c in flight. I have installed the switch just above the nose gear bay ( no door on this plane ).

If I give it a 5th flight, I start to get an orange or even red indication on recall. This is where the system is really good: you can get real inflight conditions by pushing both II and I buttons.

So to summarise, I am very confident with this device, and very happy with the extra security level it gives me without the hassle of putting 2 Voltspys downstream the batteries or even an EagleTree system.
This is for me the perfect regulator/switch for small jets, and it is rock-solid for these configurations.

felker14

My Feedback: (50)

Thanks for posting your results.

olnico

Just a little up to emphasise the importance of a proper electrical power setup with Spektrum systems...

igorcar

I like to know if it is safe to use o a UltraFlash?
Thanks

mario tavarez14

My Feedback: (37)

that wast a very good info , thank you very much

Dave Wilshere

Yes, we use the Sensor switch in all Sports jets. Flash, Ultra Flash, BVM Super Bandit etc.
I have 2 x 2200 or 2 x 3000mAh Li-Po packs and can fly 10-15 flights.

Dave W

igorcar

Thanks for the help Dave!

Igor R Carballal

Dave Wilshere

Igor

Pleasure, I really like the Sensor Switch. The one in my Original Flash has way over 500 flights and still uses the original Thunderpower Li-Po 2s 2100 Prolite packs.
I know people who have blown one side of the switch and not realised until it was obvious that one battery was not using any capacity...

Dw

sidgates

My Feedback: (2)

I can't see the pictures in this post, anyone else having this problem?

causeitflies

Sometimes happens on really old threads like this one. RCU probably tossed the old pics to free up space.