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+-- Forum: Pypilot (https://forum.openmarine.net/forumdisplay.php?fid=17)
+--- Forum: General discussion (https://forum.openmarine.net/forumdisplay.php?fid=18)
+--- Thread: Pypilot motor controller (/showthread.php?tid=1207)
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RE: Pypilot motor controller - seandepagnier - 2018-06-17
I made tests today with a hydraulic motor. The controller drives the motor fine. It draws 12 amps moving the rudder. There is a voltage drop of 0.15 votls from the controller, so 1.4 watts loss plus 0.3 watts for the arduino and mosfets driving 144 watts so 98.9% efficiency.
The barely get warm at all. I don't think they need a heat sink below 15 amps continuous power, and this agrees with my calculations, as well as measurements. Despite this I intend to use a metal box. Once I do more testing and improve the board design I hope to have it available for use with hydraulic motors, although I think cheaper controllers can also work with cooling and less efficiency.
RE: Pypilot motor controller - quetzal - 2018-06-19
I've not see all these replies, thanks ! Do you plain to release some schemes of this controller ? It look to be the best way to drive a brushed motor like my old ah2000 (moreover, i can use the control box of the ah2000 to put the mosfets and the arduino. If it work, i will see to edit the arduino code to add Button functions, to transmit back buttons push on the ah2000 old box to the rpi with openplotter. Or I can put the rpi directly in the box but I don't like it because i'm not sure about waterproofness).
RE: Pypilot motor controller - CapnKernel - 2019-07-24
I have 2 AH3000s, and I too am thinking of reusing the existing case and motor.
RE: Pypilot motor controller - CapnKernel - 2019-11-28
(2018-06-12, 09:17 PM)seandepagnier Wrote: I have been testing today a new design which drives mosfets directly from the arduino and no ESC is used.
... adapt to whatever hardware you can find that will work. I will do my best to help
Is it this one?
http://pypilot.org/schematics/hbridge_controller.pdf
What parts would you recommend for Q1-Q4, Q5, and your TVSs?
RE: Pypilot motor controller - CapnKernel - 2021-01-13
(2019-11-28, 02:55 AM)CapnKernel Wrote:(2018-06-12, 09:17 PM)seandepagnier Wrote: I have been testing today a new design which drives mosfets directly from the arduino and no ESC is used.
... adapt to whatever hardware you can find that will work. I will do my best to help
Is it this one?
http://pypilot.org/schematics/hbridge_controller.pdf
What parts would you recommend for Q1-Q4, Q5, and your TVSs?
Someone asked me in a PM what MOSFETs I've used.
For the autopilot on my boat, I use a VNH5019 module (single channel version):
https://www.aliexpress.com/item/4000046778315.html
Rds is 18mOhm per leg, which I guess means a total of 36mOhm when driving a load.
For the discrete MOSFET approach, I have been trying out the FQP30N06L, mostly because it is cheap and available here in Australia:
https://au.element14.com/on-semiconductor/fqp30n06l/n-channel-mosfet-60v-32a-to-220/dp/1695498
Rds is 27mOhm, not great, but good enough for what I want, which is to make sure any changes I make to motor.ino don't break H-bridge mode.
For my next design, I plan to use the KND3308A, mostly because JLC will fit it on my PCBs:
https://lcsc.com/product-detail/MOSFET_KIA-Semicon-Tech-KND3308A_C188764.html
Rds is 6.2mOhm, Qg is 76nC. I don't know what MOSFETs Sean uses, but he says they are 2-3mOhm, and 70nC. They probably cost a lot more than the KND3308A.
For anyone else using discrete MOSFETs, what part did you choose?
RE: Pypilot motor controller - seandepagnier - 2021-01-14
I have used a few different ones. the ones you have are 80 volt which means they have a higher on resistance
I used 40 volt ones for 12 volt and 60 volt for 24 volts to give enough reliability, I think 80v is overkill
mine cost a little more one with 4.9mohm on is C67278. I was using one with 2.5mohm on resistance and 90nC gate charge but then it became out of stock.
The wuxi ones also work and cost a lot less tend to have a little bit higher resistance for their gate charge.