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  1. S

    Open Sensorless BLDC controller

    Hey Walls, I am finding this thread very educational and learning a lot from it. Your design makes my DIY sensored BLDC controller look like a broken toaster.... :mrgreen: I'm just starting to understand sensorless detection methods. Can you give a short explanation on your BEMF detection...
  2. S

    DIY Sensored BLDC ESC - Assembly Thread

    Yesterday we assembled the ESC on an e-bike with a rear hub motor. The change to 5 Ohm gate resistors dropped the ESC temperature and even @ 40A it became only slightly warm. We did find a few bugs: - When the bike was moved in reverse the ESC acted as a brake. This is because of the current...
  3. S

    ESC Sensored to Sensorless - Possible or Not?

    Hi Amberwolf, Thanks for the confidence builder. Just wanted to know if anyone finds a problem with this "multi-core" approach ... :mrgreen: My plan is to have the main ESC MCU deal with the current liming, PWM generation & voltage cutoff. Secondary (external) MCU will read the 3 halls and 3...
  4. S

    ESC Sensored to Sensorless - Possible or Not?

    Hi, I had an idea for testing methods of BEMF detection using a sensored BLDC ESC. I would like to use an off the shelf sensored ESC as the power stage but connect an MCU to its hall sensor inputs. The external MCU will manage all the sensorless algorithm given by the throttle and BEMF...
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    DIY Sensored BLDC ESC - Assembly Thread

    Hi Tex, Thanks for the note. I have experience with temperature measurements with various kind of probes (ntc, pt100, thermocouple 2,3,4 wire) and aware of the problems with NTCs. I plan to port the code I used for a different project to read the same NTC. It uses a look up table every 5...
  6. S

    DIY Sensored BLDC ESC - Assembly Thread

    Hi, Last night we connected the ESC to my friend's home built 6S LiPo Scooter. This scooter uses an RC outrunner Brushless motor fitted with external halls. The controller worked great! The throttle endpoint adjustment via the USB interface was very simple. First we programmed the current limit...
  7. S

    DIY Sensored BLDC ESC - Assembly Thread

    Last night was a smokeless night. After fixing the controller we went on to use a current limited power supply and later on a fused 48V pack. After an initial power up with the power supply - limited to 30V we came back to the dreadful 48 pack. This time a 5A fuse was added :-) Everything...
  8. S

    DIY Sensored BLDC ESC - Assembly Thread

    Hi, Since this is our first attempt at a BLDC controller we would like to reach around 1.5kW @ 48V. Current goal is to understand why the input cap failed @ 44V input - no load... :( The design is very simple and does not implement synchronous rectification, so it will not be efficient enough...
  9. S

    DIY Sensored BLDC ESC - Assembly Thread

    Well, last night we continued working on the BLDC controller. The throttle bug is fixed and we now have a great working throttle with programmable endpoints. Next we looked at some scenarios where we saw jerking, mainly in very low RPM or "very" high RPM. I decided to try 2 things...the bad...
  10. S

    DIY Sensored BLDC ESC - Assembly Thread

    Liveforphysics sent me a PM with this exact part number. Apparently I did not go over enough ES threads... Thanks for the tip. I will source these next order from Digikey. S.B.D
  11. S

    DIY Sensored BLDC ESC - Assembly Thread

    Hi, Managed to find a decent amount of time to continue working on the BLDC controller. I found an burned battery charger in my junk and used its aluminum case as the ESC enclosure - perfect fit! Drilled the 6 mounting holes and added the FujiPoly thermal pad. For now I soldered the battery...
  12. S

    Controller builders: a gem about shoot through protection.

    Hi, I am building a brushless controller these days and read this thread with great interest. Looks like have a major misunderstanding... As I understand 3 phase BLDC drive there should be no shoot through current in a 6 step drive scheme. Lets say high side MOSFET of phase A is turned on...
  13. S

    DIY Sensored BLDC ESC - Assembly Thread

    Hi, The MOSFETs I assembled are +STP140NF7​5;16 from ST Microelectronics. Same ones I used in the brushed ESC. S.B.D
  14. S

    DIY Sensored BLDC ESC - Assembly Thread

    Today, I placed all the TO220 components on the PCB bottom side. 12 x 75V 7.5mOhm MOSFETs 1 x high input voltage regulator 1 x voltage regulator 1 x reverse polarity diode Next up, wire the board and connect the PCB to a heat sink using a thermal pad. S.B.D
  15. S

    DIY Sensored BLDC ESC - Assembly Thread

    Hi, Found little time today to continue the board assembly. Finished soldering all the Through hole capacitors and 5W 1mOhm shunt resistor. Next up will be to add the 2 voltage regulators and 12 MOSFETs. S.B.D
  16. S

    DIY Sensored BLDC ESC - Assembly Thread

    Hi, After the DIY brushed ESC success, my friend and I took the challenge and designed a sensored BLDC ESC. After reading a lot of material (thanks to ES members!) we started looking for off the shelf components to implement it. All components where taken from Digikey. I took on the hardware...
  17. S

    Yet another DIY BMS

    Hi, Found some time today to continue PCB routing. I managed to get around 80% done. As it looks now I may have to make the board a bit wider in order to make the discharge traces wider. So final PCB size will probably be 10cm X 25cm. I hope to get this finished in the coming week.... S.B.D
  18. S

    Inexpensive Load Tester

    My friend built a load using a bathroom heater. He got about 1 ohm of resistance by paralleling the resistance wire on the ends and in the middle. It can sink around 1.3kW at 36V. Nice thing that the heater has a built in fan to cool the load.
  19. S

    Meanwell NES Schematic..almost complete

    Hi Neil, Thanks for the link. Looking at the schematics I see the main difference between the circuits. Mine uses the op amp in linear mode as opposed to open loop ("comparator mode"). Can't this cause a large output voltage ripple and maybe instability as the comparator has only two output...
  20. S

    Meanwell NES Schematic..almost complete

    Hi, I don't think I ever mentioned I invented anything and have never seen the circuit you are talking about. I can just be proud of the fact that my circuit is very similar as you say ( I am not sure how many ways you can go with external current limiting). My hobby is electronics and I build...
  21. S

    Meanwell NES Schematic..almost complete

    Hi Neil, I'm not trying to reinvent the wheel just make is spin a bit faster :D . My motivation here is to find the easiest way get configurable current limiting with minimal tapping into the PSU internals. If I use a 5V external regulator driven from the PSU output voltage I think I can get...
  22. S

    Meanwell NES Schematic..almost complete

    Hi Cor, I got your point on increasing the shunt resistor's value. I just looked around to see what I have in my junk drawer. This is also true for the 5V supply. I only have 5V op amps on hand... Maybe it's time I will get some higher voltage op amps from the local store. In the circuit the...
  23. S

    Meanwell NES Schematic..almost complete

    Hi Cor, What do you think about the attached current limiter circuit for the NES Power Supply? Circuit operation: -The current is sampled with a 1mOhm shunt resistor. -Shunt resistor voltage is amplified by the rail2rail op amp. -Op amp gain is set in such a way that the output reaches...
  24. S

    Yet another DIY BMS

    Hi, Made some progress this weekend and finished the component placement on the PCB. Even started routing tests on the "Cell Units". PCB size is 3.15" x 9.85" (80mm X 250mm). Don't know how much time I'll have in the coming days to continue :cry: I need to give some attention to projects...
  25. S

    Meanwell NES Schematic..almost complete

    Hi Neil, I did have a look at it, and to my understanding the relay in normally open when mains power is applied. After the large input caps (2 X 600uF)charge slowly through the series resistor, the LDO ( Q5 ,ZD2 and the 3.9K resistor) can source the power for the relay to close, in order to...
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