jtrout19

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Current/Voltage sensor choices???
« on: June 01, 2016, 05:44:16 am »
Hey guys been a while. I was flying my quad the other day when all of the sudden the thing fell out of the sky. Upon inspection an 8pin component on my power distribution board had blown. http://www.hobbyking.com/hobbyking/store/__68699__HK_Pilot_Power_VI_Module_Distribution_Board_And_Dual_UBEC_ALL_In_One_120A_and_10s_AR_Warehouse_.html?strSearch=hk%20pilot%20power That is the one I purchased. you can see the board has 2 8pin IC's. Anyway I am looking at other options at this point. I liked this one due to the fact of the volt and current sensors being on the board. That being said what are my options for sensor that will work with the Revolution? Thanks!

jtrout19

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Re: Current/Voltage sensor choices???
« Reply #1 on: June 01, 2016, 06:31:48 am »
So the regulators on this board are http://www.mouser.com/ProductDetail/Monolithic-Power-Systems-MPS/MP2560DN-LF/?qs=rC7bBWoQAAleyiym%2FnQvhQ%3D%3D Looking at the datasheet it shows them being 2.5a outputs. Seems a little low to me. I guess I could always replace the regulator. I would like to replace it with a 5A output one. That being said I cannot find one with the same pinout. Any ideas?

Mateusz

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Re: Current/Voltage sensor choices???
« Reply #2 on: June 01, 2016, 01:07:17 pm »
Hi,

I don't get why would you need 5A (Ampers) regulator ? I power FC, Camera, 600mW TX, OSD, GPS, etc... with 0.68A at most.
You probably meant 5V (volts) ?

Are you sure it's regulator that got damaged ? Cause regulator to me is the chip in SOT23-5 package, top right corner close to connector. But hard to tell from this picture without schematics.
Perhaps you could take a photo of your broken board ?

f5soh

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Re: Current/Voltage sensor choices???
« Reply #3 on: June 01, 2016, 02:15:55 pm »
You cannot just replace the 8pin chip for bigger current.
This type of stepper regulator depends also in components around, basically a diode and a coil.

The small sot23 package refers to the current sensor.
Generally like this one: http://www.ti.com.cn/general/cn/docs/lit/getliterature.tsp?genericPartNumber=ina138&fileType=pdf

Another solution if you need only 5V, you can replace one or two resistors (voltage divider) in 12V module for another 5V output.
See page16, R1/R2 resistor in MP2560 datasheet.

jtrout19

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Re: Current/Voltage sensor choices???
« Reply #4 on: June 01, 2016, 04:23:01 pm »
Hi,

I don't get why would you need 5A (Ampers) regulator ? I power FC, Camera, 600mW TX, OSD, GPS, etc... with 0.68A at most.
You probably meant 5V (volts) ?

Are you sure it's regulator that got damaged ? Cause regulator to me is the chip in SOT23-5 package, top right corner close to connector. But hard to tell from this picture without schematics.
Perhaps you could take a photo of your broken board ?

I was thinking the same thing but yes the 8 pin chips are the regulators http://www.mouser.com/ProductDetail/Monolithic-Power-Systems-MPS/MP2560DN-LF/?qs=rC7bBWoQAAleyiym%2FnQvhQ%3D%3D That is the regulator that is on the board. One for the 12v BEC and the other for the 5v BEC. I just dont understand why it failed unless it was a bad component. I have my Camera, OSD, FC, GPS, and Receiver powered off the 5v BEC. I did not think that would pull more than 2.5a.
 
You cannot just replace the 8pin chip for bigger current.
This type of stepper regulator depends also in components around, basically a diode and a coil.

The small sot23 package refers to the current sensor.
Generally like this one: http://www.ti.com.cn/general/cn/docs/lit/getliterature.tsp?genericPartNumber=ina138&fileType=pdf

Another solution if you need only 5V, you can replace one or two resistors (voltage divider) in 12V module for another 5V output.
See page16, R1/R2 resistor in MP2560 datasheet.

And I was thinking about that issue as well. Although I know that in some of my other applications I have been able to swap components out for upgrades and it work alright. I didnt know if it would be the same in this scenario. I need the 12v bec. I have some new MP2560DN's on their way. I am going to try just replacing the pair of them and see what happens. I just dont want the quad falling out of the sky again. Luckily when it happened i was only about 5 feet off the ground. What would happen if the thing shut off and i was 100 feet in the air!?!!!??!! OUCH!

Mateusz

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Re: Current/Voltage sensor choices???
« Reply #5 on: June 01, 2016, 05:40:33 pm »
I just dont understand why it failed unless it was a bad component. I have my Camera, OSD, FC, GPS, and Receiver powered off the 5v BEC. I did not think that would pull more than 2.5a.
I am not a hardware person, but to me also it seems very unlikely that it could pull 2.5A... the only scenario that I can think of when it happens is a short circuit. Also what ESCs are you using.
Some ESCs can produce voltage spikes damaging electronics http://www.fluxfpv.com/fix-little-bee-voltage-spikes/
So in theory, if your regulator got damaged from voltage spike, something could get shorted (maybe) and hence failure ? Again I am not hardware guy, just guessing :)

By the way I am happy with this sensor http://www.lawicel-shop.se/prod/AttoPilot-Volt--Current-BoB-90A_819561/CurrentVoltage_77548/ENG/SEK which I have soldered on the cable between battery and PDB.

jtrout19

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Re: Current/Voltage sensor choices???
« Reply #6 on: June 02, 2016, 01:12:35 am »
I just dont understand why it failed unless it was a bad component. I have my Camera, OSD, FC, GPS, and Receiver powered off the 5v BEC. I did not think that would pull more than 2.5a.
I am not a hardware person, but to me also it seems very unlikely that it could pull 2.5A... the only scenario that I can think of when it happens is a short circuit. Also what ESCs are you using.
Some ESCs can produce voltage spikes damaging electronics http://www.fluxfpv.com/fix-little-bee-voltage-spikes/
So in theory, if your regulator got damaged from voltage spike, something could get shorted (maybe) and hence failure ? Again I am not hardware guy, just guessing :)

By the way I am happy with this sensor http://www.lawicel-shop.se/prod/AttoPilot-Volt--Current-BoB-90A_819561/CurrentVoltage_77548/ENG/SEK which I have soldered on the cable between battery and PDB.

I am using afro 30a esc without BEC's. I went with the big boys for possibility of using bigger stuff in the future. I guess I will see when I get the new regulators. If it blows again then I got a short. If not more looking into is required