Search found 60 matches

by lizardmech
Jan 17 2019 11:27am
Forum: Motor Technology
Topic: DA-90 motor
Replies: 18
Views: 1189

Re: DA-90 motor

I couldn't find detailed motenergy efficiency graphs. I was looking at it compared to the 3kw golden motor axial flux motor. The DA-90 had almost 3x the peak torque at 0 RPM if you feed it enough current, at 4000 RPM the golden motor had lost over 50% of it's rated power and ceased producing torque ...
by lizardmech
Jan 17 2019 10:10am
Forum: Motor Technology
Topic: Esc current sensing
Replies: 18
Views: 223

Re: Esc current sensing

Thanks to all for replies and comments. I would like to jump back into the senseing. Instaspin foc requires phase voltage and phase current senseing plus a few others. Ina240 for inline current measurment and should i sense the phase voltage before or after the shunt resistor. Thanks everyone again...
by lizardmech
Jan 17 2019 10:06am
Forum: Motor Technology
Topic: DA-90 motor
Replies: 18
Views: 1189

Re: DA-90 motor

It looks like although peak power and efficiency aren't noteworthy it has quite a large RPM range where it has decent power and efficiency. It has a new winding method made by some russians using parallel star and delta winding. The heavy weight seems to be as it is an existing motor with new windin...
by lizardmech
Jan 17 2019 7:55am
Forum: Resources & EV Related Parts and Services
Topic: Duyunov wheel-hub motor
Replies: 65
Views: 3982

Re: Duyunov wheel-hub motor

Actually these might be quite good, looking at the dyno graphs the peak power and efficiency aren't notable, however they appear to have a broader operating range where they still outputting power with decent efficiency when compared to permanent magnet motors. It also looks like they can tolerate a...
by lizardmech
Jan 15 2019 9:38pm
Forum: Motor Technology
Topic: Esc current sensing
Replies: 18
Views: 223

Re: Esc current sensing

They still haven't released the instaspin software for the 280049. It was supposed to be out q2 or q3 2018 now it's q2 2019. :roll: The 280049 does look pretty good though. ok, but they are a great design for motor control especially in this price point. The F28379S/Ds are to expensive and no one r...
by lizardmech
Jan 15 2019 2:44am
Forum: Motor Technology
Topic: Esc current sensing
Replies: 18
Views: 223

Re: Esc current sensing

They still haven't released the instaspin software for the 280049. It was supposed to be out q2 or q3 2018 now it's q2 2019. :roll: The 280049 does look pretty good though.
by lizardmech
Jan 15 2019 12:31am
Forum: Motor Technology
Topic: Esc current sensing
Replies: 18
Views: 223

Re: Esc current sensing

If you can stay under 80V the Ti ina240 is probably the best option. Anything above that and you will need complex isolated shunt sensors or magnetic based sense such as allegro ACS sensors.
by lizardmech
Jan 14 2019 11:40am
Forum: Motor Technology
Topic: Esc current sensing
Replies: 18
Views: 223

Re: Esc current sensing

Thanks for the reply. I have read countless data sheets, app notes and ref designs on SLBLDC motor controller design and construction 85% i fully get and the rest in over my head. Vishay has a .0003 ohm resistor that will put out about 5 watts of heat in my app, well within the soa of the resistor....
by lizardmech
Jan 13 2019 2:52pm
Forum: Motor Technology
Topic: VESC-controller
Replies: 181
Views: 31159

Re: VESC-controller

I should give instaspin a try. I used C2000's for other power applications, but not motot control. I think I saw Lmax and Lmin in their motor parameters which led me to think they use a saliency-based observer. 0.1uF sounds like a very agressive filter with lots of phase lag at high speed. I wonder...
by lizardmech
Jan 13 2019 1:34am
Forum: Motor Technology
Topic: VESC-controller
Replies: 181
Views: 31159

Re: VESC-controller

Looks similar to how Ti instaspin foc motor detection works, you give it a target current and ERPM combined with a ramp up period to slowly build ERPM in open loop sinusoidal mode. The only difference is they have 0.1uf filter caps on voltage phase sense, they seem to be able to track the rotor posi...
by lizardmech
Jan 09 2019 10:06am
Forum: Motor Technology
Topic: Sensorless at standstill, development updates and status
Replies: 78
Views: 4304

Re: Sensorless at standstill, development updates and status

You can still sell IP and open source it, you just release it under a GPL license which requires the source code be distributed for the license to be valid, commercial customers typically won't want to release source codes for their products so you negotiate a non-GPL license with whatever terms you...
by lizardmech
Jan 07 2019 7:42pm
Forum: Motor Technology
Topic: Sensorless at standstill, development updates and status
Replies: 78
Views: 4304

Re: Sensorless at standstill, development updates and status

I actually never used processors from TI because their software is/was not available for Ubuntu Linux. TI C2000 processors come with an Eclipse-based IDE that works on linux. Been using it for quite a while in my ubuntu laptop, works ok provided your machine can haul Eclipse. If your main value is ...
by lizardmech
Jan 07 2019 2:11am
Forum: Motor Technology
Topic: Sensorless at standstill, development updates and status
Replies: 78
Views: 4304

Re: Sensorless at standstill, development updates and status

I assume it is considered valuable IP (giving a real advantage over competitors) so they keep quiet about it. TI for instance can patent their method but everyone can read the patents and copy the system. Including the whole of China. So I can imagine they just keep quiet about it. You may also be ...
by lizardmech
Jan 06 2019 4:21am
Forum: Motor Technology
Topic: Sensorless at standstill, development updates and status
Replies: 78
Views: 4304

Re: Sensorless at standstill, development updates and status

All I think about when I hear open source is lots of companies getting rich of my work without any kickback to me (even though I spent a few 100k$ worth of time and thousands of my own money on computers, lab equipment and parts). Second, as an unemployed at the moment I also think about all the pe...
by lizardmech
Jan 05 2019 1:03am
Forum: Motor Technology
Topic: Sensorless at standstill, development updates and status
Replies: 78
Views: 4304

Re: Sensorless at standstill, development updates and status

Thinking about what to do now with this tech. I do not plan a controller IC with this as for me it is more of the same, basically lots of not interesting work. Also setup might be too difficult and would ideally require a PC with Labview for drawing performance diagrams. I was thinking about buildi...
by lizardmech
Nov 02 2018 6:48am
Forum: Motor Technology
Topic: High side vs Low side PWM
Replies: 74
Views: 4390

Re: High side vs Low side PWM

Usually high PWM freq and high switching speed allows you to have less bulk capacitance however it's more demanding on minimizing layout inductance and capacitor ESR. For 100khz you would typically expect to see SMD mosfets and ceramic capacitors placed 1 or 2 millimeters from the drain. Through hol...
by lizardmech
Oct 29 2018 9:33am
Forum: Battery Technology
Topic: DIY Super Capacitors, and Robert Murray-Smith
Replies: 29
Views: 2277

Re: DIY Super Capacitors, and Robert Murray-Smith

I have been following him for a while as well. He says he is getting close to starting limited production and seems to have a work space set up. Interestingly I was talking to him in youtube comments, assuming he gets working ones he was unsure what sort of markets to sell them to. His current plan ...
by lizardmech
Oct 29 2018 8:41am
Forum: Motor Technology
Topic: Switched Reluctance Motors
Replies: 49
Views: 4125

Re: Switched Reluctance - Ideal for DD Hubs?

The biggest difference between synchronous reluctance and switched is that sync ones typically have the phases all joined together like conventional 3 phase motors. Switched reluctance typically have completely separate phases that each have their own ground connection.
by lizardmech
Oct 22 2018 7:41am
Forum: Motor Technology
Topic: Switched Reluctance Motors
Replies: 49
Views: 4125

Re: Switched Reluctance - Ideal for DD Hubs?

The main downside is apparently less torque than PM motors, I have read they're a little prone to noise and vibration due to the way they switch. The advantage is they have no BEMF so torque is constant across the entire RPM range, this also means voltage and turns have no impact on maximum RPM and ...
by lizardmech
Oct 07 2018 10:00am
Forum: Motor Technology
Topic: How much Heat can To-247 handle in real world
Replies: 10
Views: 433

Re: How much Heat can To-247 handle in real world

One thing to be aware of is much of the time TO-247 are limited by the wirebond to the source pin, it's not uncommon to see 200A+ mosfets dies in TO packages with a 100A limit on the wirebond. You have to check the data sheet for any mention of package limitations.
by lizardmech
Oct 07 2018 9:54am
Forum: Motor Technology
Topic: VESC for ebike ?
Replies: 12
Views: 1415

Re: VESC for ebike ?

There's a new Ti DRV chip for 100V now. Not a drop in replacement but it would allow a fairly cheap and compact version that supports higher voltages. The best it could manage was 6x 100v 1.5mohm FETs so current would be limited by however much you could run through those without overheating. More t...
by lizardmech
Jul 14 2018 10:16am
Forum: Motor Technology
Topic: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW)
Replies: 3346
Views: 149602

Re: KT motor controllers -- Flexible OpenSource firmware for BMSBattery S/Kunteng KT motor controllers (0.25kW up to 5kW

there are some open source examples for driving a BLDC with FOC on a STM32, so you won't have to start from scratch. I would prefer if we could write an open firmware for the Lishui controllers , they use STM32 processors and offer sensorless sinusodial drive. regards stancecoke That's actually pre...
by lizardmech
Jun 08 2018 8:03am
Forum: Motor Technology
Topic: Building a 100% DIY ESC for motors
Replies: 34
Views: 1811

Re: Building a 100% DIY ESC for motors

At the time of the incident, the battery that I was using was 25 volts. The resistance of the motor was 200mΩ, the battery was 35mΩ, and both FETs 65mΩ. 25 volts into 300mΩ gives 83 peak amps. Half that into a 60mΩ FET gives a whopping 103 watts. Bang! I never thought that surges could be that bad....
by lizardmech
Jun 01 2018 3:27am
Forum: Motor Technology
Topic: FOC identification
Replies: 10
Views: 474

Re: FOC identification

A hobbywing unit. It is only compatible with their motors and offers no tuning of motor parameter, so it's quite limited in this regard. Looking at it, it probably is FOC, it won't run other motors as FOC needs to know the motor resistance, inductance and flux linkage. FOC controllers have to eithe...
by lizardmech
May 31 2018 10:09pm
Forum: Motor Technology
Topic: FOC identification
Replies: 10
Views: 474

Re: FOC identification

Which controller is it?