Re: [Paparazzi-devel] YAPA2 help needed "SOLVED"

[gatib]

Hi,

thank you for making us aware of a potential danger of low cost current
sensors. This explains also that the voltage display on the GCS failed.

Balazs

> Only ADC inputs with a voltage devider (YAPA/TWOG) are slightly current
> limited. Other inputs are totally unprotected.
>
> -Christophe
>
>
>
> On Fri, Aug 10, 2012 at 9:46 AM, Chris <address@hidden> wrote:
>
>> I did some calculations after downloading the INA169 manual and the
>> Attopilot schematic
>> The results are horrifying.
>> The current sensor's output is not current limited as it does not have
>> any
>> resistor in line with the output
>> and the output follows the I*Rs *(72.3K/1K) formula (72.3K/1K is the
>> op-amp's gain)
>> Assuming a surge current of 100A which is low when thick wiring, low ESR
>> capacitors
>> and high voltage is used we get an output of 7.23v with no current
>> limiting.
>> A 150A surge current  will give an output of 10.8v Arggghhhh.....
>> Chris
>>
>>
>> ______________________________**_________________
>> Paparazzi-devel mailing list
>> address@hidden
>> https://lists.nongnu.org/**mailman/listinfo/paparazzi-**devel<https://lists.nongnu.org/mailman/listinfo/paparazzi-devel>
>>
> _______________________________________________
> Paparazzi-devel mailing list
> address@hidden
> https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
>