where does the mosfet temp value come from?

General topics and discussions about the VESC and its development.
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable
scienceworks
Posts: 29
Joined: 27 Mar 2016, 16:27
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

where does the mosfet temp value come from?

Postby scienceworks » 27 Mar 2016, 21:50

there are no temp sensors in the fets, so i assume it is interpolated from some ohter value. i noticed that the value is influenced when touching the board, which made me think it might be calculated based on the on resistance of the fets?
am i missing something?
i havent found any information regarding the temp value, and im not codery enough to just look it up in the firmware (i wpuld propably be able to, but it would take me hours :roll: )

i bet its something trivial....

joe90
Posts: 49
Joined: 15 Dec 2015, 16:52
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: where does the mosfet temp value come from?

Postby joe90 » 27 Mar 2016, 22:14

There is a thermistor on the board betwen fets.
But 6 readings I dont know. They seem to read the same temperature.
Michel Cote
Twin v4.7 + SK3 6374 149KV
Bicycle
2500W peak/unit on 12S

scienceworks
Posts: 29
Joined: 27 Mar 2016, 16:27
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: where does the mosfet temp value come from?

Postby scienceworks » 27 Mar 2016, 22:20

yeah i know that there is a thermistor on the pcb, but that one is labled as PCB sensor in the data graph.

rew
Posts: 943
Joined: 25 Mar 2016, 12:29
Location: Delft, Netherlands.
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: where does the mosfet temp value come from?

Postby rew » 28 Mar 2016, 20:34

I have been looking at the code.

The code is prepared for more sensors. One for the PCB (CPU? DRV8302?), one for each mosfet, and one for the motor.

However, in current implementations many map to the same physical sensor. This means that adding the sensors later on is easier I guess.

Hummie
Posts: 110
Joined: 10 May 2016, 04:05
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: where does the mosfet temp value come from?

Postby Hummie » 07 Aug 2016, 17:04

so even though there are different graphings of temp for different fets that show up on the bldc tool realtime data they're all hooked to the same temp sensor?

ViennaTom
Posts: 41
Joined: 21 Apr 2016, 13:06
Location: Austria/Vienna
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: where does the mosfet temp value come from?

Postby ViennaTom » 07 Aug 2016, 21:12

yes !

Svenska
Posts: 15
Joined: 02 May 2016, 12:41
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Re: where does the mosfet temp value come from?

Postby Svenska » 08 Aug 2016, 08:57

I'm fairly certain that there is only one spot where the temperature is measured.

Image

On the bottom right you see a thing labelled "NTC 10K". That is a resistor that changes value with temperature. If you grab your VESC and put your finger on it you will see the temperature shoot up.

Here is some info on how these things work:



In this picture you can see it between the connector marked "I2C/UART/ADC" and the bottom MOSFET. It is labelled R1 and can be found in the BOM in line 6.

Image

Please correct me if I missed something but as far as I can see after having build a few of these that is the only component on the board that is capable of measuring a temperature.

Hope that helps.

-Svenska


[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Return to “General”

Who is online

Users browsing this forum: No registered users and 3 guests