Originally Posted by jj604

Actually that's what I wsa suggesting in my first set of improvements number 3. "Each of LV alarm, 6x cell voltages and the current would flash in turn for say 3 secs and while flashing you use the Bind or Power button to increment or decrement the value".

The reason I put it there was it could be done without any physical change to the unit by adding another switch. Just needs a firmware change.

Yep and if they are willing to make a firmware change, then they could also create a pc program communicating with the USB port so you can do all settings/offset changes explained above in item 2 via this program

Originally Posted by jj604

It needs at least two cells "live" to run and if you put the variable signal on another pin you have a common ground problem.
You can't feed the signal into the current sense input as that is 3.3V digital logic not analog.

If only one battery is used to power the BEC and motor (the entire aircraft), wouldn't the -ve all go back to the battery? i.e. a common ground?

As for the input voltage, the RSSI voltage will need to be adjusted (amplified or reduced) so that it falls between 3.3 to 4.2 volts.

Maybe I'm naive, but I don't see why this is an impossible thing.

BB

Absolutely, that's a good solution. However that's only useful as a secondary method. Setting alarms etc needs to be able to be done at the field and most folks don't cart around a PC with them when flying.

Originally Posted by jaccies

Yep and if they are willing to make a firmware change, then they could also create a pc program communicating with the USB port so you can do all settings/offset changes explained above in item 2 via this program

Originally Posted by jj604

Absolutely, that's a good solution. However that's only useful as a secondary method. Setting alarms etc needs to be able to be done at the field and most folks don't cart around a PC with them when flying.

right but at the field you need to change only the lipo capacity for the 20% alarm when using different lipo's at the field, the rest you do once athome

See if I can explain without a picture.

The Quanum ANALOG cell voltage measurement occurs by a voltage between 3 and 5V across each pair of pins.The device logic requires a voltage between pins 1-2 and 2-3 for it to work. Any more (3S-6S) are optional but there has to be a voltage across every pin from 1 up to the last one. If you connect a separate 0-5V analog signal between two pins. the -ve has to go to a pin that alreday has a cell +ve attached.That cell then has it's +ve connected through to its negative via the Rx ground. It's easier to understand if you sketch it out.

Originally Posted by borneobear

If you use only one battery to power the entire aircraft, would the ground all go back to the battery -ve? i.e. a common ground?

As for the input voltage, the RSSI voltage will need to be adjusted (amplified or reduced) so that it falls between 3.3 to 4.2 volts.

Maybe I'm naive, but I don't see why this is an impossible thing.

BB

Thanks, I've added the idea as #2 in Post 5.

Originally Posted by jaccies

right but at the field you need to change only the lipo capacity for the 20% alarm when using different lipo's at the filed, the rest you do once athome

Originally Posted by jj604

See if I can explain without a picture.

The Quanum ANALOG cell voltage measurement occurs by a voltage between 3 and 5V across each pair of pins.The device logic requires a voltage between pins 1-2 and 2-3 for it to work. Any more (3S-6S) are optional but there has to be a voltage across every pin from 1 up to the last one. If you connect a separate 0-5V analog signal between two pins. the -ve has to go to a pin that alreday has a cell +ve attached.That cell then has it's +ve connected through to its negative via the Rx ground. It's easier to understand if you sketch it out.

Yes I get it now.
Pins 1-2 & 3 must be connected to the battery.
RSSI input comes in from say pin 3 to 4.
But its not actually the RSSI input. Its an indirect connection via a rail-to-rail I/O OpAmp. So the supply is coming from the battery cell leads, but adjusted (indirectly) in relation to the RSSI value via the OpAmp.

Is this workable?

BB

Suggest you ask this on the electronics thread where there are folks who know a lot more about this than I do.

Here's a very crude picture that may help. Feel free to use it.
The black wires show the short caused by the common ground.

John

Originally Posted by borneobear

Yes I get it now.
Pins 1-2 & 3 must be connected to the battery.
RSSI input comes in from say pin 3 to 4.
But its not actually the RSSI input. Its an indirect connection via a rail-to-rail I/O OpAmp. So the supply is coming from the battery cell leads, but adjusted (indirectly) in relation to the RSSI value via the OpAmp.

Is this workable?

BB

Its a very nice diagram by any standards John. Thanks.

The system should definitely not be wired like that. High chance of seeing expensive smoke.

BB

Originally Posted by jj604

3) The current sensor is an Allegro ACS755xCB-100. This is a 100Amp rated Hall effect sensor - data sheet here http://www.allegromicro.com/en/Produ...5/0755-100.pdf

oops the hall sensor is a Discontinued Product!!!!!

Just means they have replaced it with a newer model last month with improved specs. A month ago it was the bee's knees. Maybe Quanum got a cheap job lot when it was discontinued!

Originally Posted by jaccies

oops the hall sensor is a Discontinued Product!!!!!

Hi
Thx for very good info about this system!

I still have few questions:

What is the minimum cell voltage and alarm threshold? Can this system be used with A123 cells?

and what is mAh alarm range? I assume it is 0-9999mAh

I didn't try it below 3.2V and yes it works with A123's. You get the default beeper at 3.2V (measured at 3.24V on mine) which you can't turn off though and would drive you nuts.

Well you can - with a pair of sidecutters and by opening the case . But be careful with the two tiny switches - they fall apart if you look at them when the case is open.

I'll have a look at it again today and check the lowest voltage and max mAh for you.

Regards, John

Originally Posted by gr8

Hi
Thx for very good info about this system!

I still have few questions:

What is the minimum cell voltage and alarm threshold? Can this system be used with A123 cells?

and what is mAh alarm range? I assume it is 0-9999mAh

It turns out to be a bit tricky to measure all 6 cell voltages over a wide range since the first two cells (Pins 1-2 and 2-3) draw significantly more current than all the others. The Tx gets its power from the voltage across pins 1 and 3 obviously. So a simple variable supply and resistor network won't work.

I tested it originally with charged and discharged LiPos and a discharged A123 and found the voltage accuracy across all 6 fine.

I have edited Post 5 to add some info on what happens when you vary the voltage across the supply (ie Pins 1,2,3).

In short it keeps working accurately for cell voltages from 2.0 - 5.0 Volts. You can't change the beep from 3.2 volts though.

John

HI!

If you want pro telemetry systems which monitors current, voltage and consumed amps look this.

Jeti Duplex 2.4 GHz system
http://www.jetimodel.com/index.php?p...d=0&category=4
http://www.jetimodel.com/index.php?page=product&id=22

"MUI sensors allow setting of acoustical signals in order to announce violation of set parameters. Such alarms may be set for measuremets of maximum current and minimum voltage as well as for a maximum of consumed battery capacity. The sound signal is generated by a siren integrated in the transmitter module. For better differentiation are the particular alarms distinguished by Morse alphabetic letters. The acoustical alarm generation in case of parameter violation is working even if the JETIBOX is not connected. With the JETIBOX in place the LCD display shows which parameter has been violated. In case of violation of several parameters the alerts alter consecutively as well as the indications on the LCD display."