@chilidress Sorry, contains trade secrets. Schematic is huge. The circuit also has a CPLD and an MCU - lots of code. There are simpler controllers you could probably look up online.
How do you select which capacitors or varistors that will eliminate the power factor? Also, if the motor is rated at something like "115V 60Hz 7.1A" and the resistance across it's terminals is 2.5 ohms. Would the theoretical inductance be:
|Z| = 115/7.1
sqrt(2.5^2 + 2*pi*60*L^2) = 16.20
L = sqrt(16.2^2 - 2.5^2) / (2*pi*60)
L = 42 mH
Are you using the microcontroller to put 3 phase square wave into the MOSFETS or transistors? Are you varying the current, voltage or frequency?
@baboracus This isn't an AC motor - it's a DC brushless... can't help you with inductance calculations of an AC motor.
Unlike an AC motor, the frequency is completely adaptive because the controller is always reading the motor and applying a field that is a few degrees ahead of the rotor position. The controller doesn't care about resistance or inductance, and can run an ironless (super low inductance) motor.
@baboracus The micro chooses which FETs apply a field slightly ahead of the motor position and applies a 100kHz center-balanced PWM. Variations in speed, voltage, current and frequency are side-effects of motor resistance, inductance, load and the PWM duty cycle.
@nuriqa88 You don't want something this big though, it requires gigantic transistors. Usually, you'd want something with an encoder; making one that uses back-EMF is very difficult. I don't know where you can get one, but you could try searching for "DC Brushless Motor with encoder" on Google Shopping.
@karlsruheprotest It's well anchored, and the propeller is rated for far more than that load. While the propeller could chuck low-density stuff that gets caught by the air at my victim there, if the propeller managed to come off the motor (by moving forward off the motor's axle), its own thrust would push it backward at me! After this 1.5HP, we decided it'd be best to move it outside.
@karlsruheprotest Haha, this was only ~1.5HP We hit more than 9HP at one point, I posted the vid.
I forgot the thrust we calculated. At 9HP, it was probably more than 75 pounds.
You could derive the RPM from the audio pitch in the video (then divide by number of blades), and then look up the thrust from the propeller's RPM-to-thrust curve.
@stimps90 Try hobbyking. It's a Turnigy 180 7000W motor. Cheap too - only around $100. However, being a brushless motor, you'll need a controller (which is what I was developing in this video), and they can be a bit more expensive. The controller that was designed for this motor (also at hobbyking) sucks terribly, it induces BAD eddy currents in the motor, making it get really hot. And you'll need a controller that sends the right speed-control signal. Good luck!
@heberorozco A brushless motor will last many, many times longer than a brushed motor. The only moving part is the bearing. They usually don't get as hot (for the same amount of power), so you can put lots more power in before worrying about it failing.
@QuantumDevices With full heat sinking, those FETs can do >100 amps each. The switching rate in the video is 150KHz (I can run it up to 400Khz); the FETs turn on and off very quickly, which causes some pretty major spikes. The electrolytics are there to absorb that. The back EMF is clamped with diodes but is otherwise floating.
I think there are better options in terms of low ESR caps, but they're hard to find.
Check out the newer videos, the full circuit has 18 caps.
It is a custom controller and software. This may end up being a commercial endeavor, so I will not be sharing either, sorry!
The controller can operate sensorless (using back-EMF), with a pair of hall sensors, or with a 2-axis magnetometer. The theoretical limit of the circuit (with proper heat-sinks) is over 100kW... although realistically, I only expect to ever see 50kW out of it.
It's intended to run an ironless hub motor, which saves the whole issue of a chain and gearing.
I wrote all of the software on the controller -- It's a custom set-up because I'm doing things for efficiency that nobody else does. The PC is just running a terminal program to send speed values (0-255) to the controller.
You can't really measure the voltage across the wires in DC. You might be able to get a reading as AC, but it won't tell you anything useful.
The voltage I'm reading is across the battery -- Batteries fluctuate a lot when you're drawing power from them, so it's important to know how much they're really providing.
Sweet! Now you can make your own wind tunnel :). I find it hard to believe thet that tiny motor is acctually capable of handiling the current that would be going through its windings at 9 HP.. thats some where around 6,4 KW..and 6400 W / 24 V = 266 A... :O or is the motor designed for mutch higher voltage than you were using? But super awsome video!
wow that was a beast..but the guy on the sofa kinda rised his life..i mean if the prop would have broken free..it wud have gone straight for him..bt nevrthelss great vid
If the prop broke free, since it is pushing air toward him, it would be pushed back towards me... Considering failure is not an option on airplanes, this propeller was definitely NOT going to break (It is a real aircraft propeller). What was more likely was one of the numerous papers or trinkets flying off the desk towards him!
Awesome setup, but seriously, I wouldn't sit in front of propeller.....any catastrophic (unk unk) failure could result in someone's head getting sliced off!
schematic? i'm gonna try this at a 13v 80 amp car alternator muhahaha
chilidress 4 months ago
@chilidress Sorry, contains trade secrets. Schematic is huge. The circuit also has a CPLD and an MCU - lots of code. There are simpler controllers you could probably look up online.
KippTheKidd 4 months ago
How do you select which capacitors or varistors that will eliminate the power factor? Also, if the motor is rated at something like "115V 60Hz 7.1A" and the resistance across it's terminals is 2.5 ohms. Would the theoretical inductance be:
|Z| = 115/7.1
sqrt(2.5^2 + 2*pi*60*L^2) = 16.20
L = sqrt(16.2^2 - 2.5^2) / (2*pi*60)
L = 42 mH
Are you using the microcontroller to put 3 phase square wave into the MOSFETS or transistors? Are you varying the current, voltage or frequency?
baboracus 5 months ago
@baboracus This isn't an AC motor - it's a DC brushless... can't help you with inductance calculations of an AC motor.
Unlike an AC motor, the frequency is completely adaptive because the controller is always reading the motor and applying a field that is a few degrees ahead of the rotor position. The controller doesn't care about resistance or inductance, and can run an ironless (super low inductance) motor.
KippTheKidd 5 months ago
@baboracus The micro chooses which FETs apply a field slightly ahead of the motor position and applies a 100kHz center-balanced PWM. Variations in speed, voltage, current and frequency are side-effects of motor resistance, inductance, load and the PWM duty cycle.
KippTheKidd 5 months ago
Probably not. You'd want about 50HP on a drifter. This motor can put out about 10 (it was only 1.5 in this video - I have another vid that's 9.5HP)
KippTheKidd 10 months ago
Would this be powerful enough to lift an ultralight plane?
killer00630 11 months ago
where can I get Brushless DC motor?I need to do A low cost Brusless Dc motor controller using 8 bit microcontroller...
nuriqa88 1 year ago
@nuriqa88 You don't want something this big though, it requires gigantic transistors. Usually, you'd want something with an encoder; making one that uses back-EMF is very difficult. I don't know where you can get one, but you could try searching for "DC Brushless Motor with encoder" on Google Shopping.
KippTheKidd 1 year ago
Cool! Thanks for that, if i can find a siutable circuit design i might get one! Would be perfect to start the jet
stimps90 1 year ago
@karlsruheprotest It's well anchored, and the propeller is rated for far more than that load. While the propeller could chuck low-density stuff that gets caught by the air at my victim there, if the propeller managed to come off the motor (by moving forward off the motor's axle), its own thrust would push it backward at me! After this 1.5HP, we decided it'd be best to move it outside.
KippTheKidd 1 year ago
@karlsruheprotest Haha, this was only ~1.5HP We hit more than 9HP at one point, I posted the vid.
I forgot the thrust we calculated. At 9HP, it was probably more than 75 pounds.
You could derive the RPM from the audio pitch in the video (then divide by number of blades), and then look up the thrust from the propeller's RPM-to-thrust curve.
KippTheKidd 1 year ago
Ive never seen such a tuff little motor! I want to get my hands on one of these to start my jet engine! Where do u get these motors?
stimps90 1 year ago
@stimps90 Try hobbyking. It's a Turnigy 180 7000W motor. Cheap too - only around $100. However, being a brushless motor, you'll need a controller (which is what I was developing in this video), and they can be a bit more expensive. The controller that was designed for this motor (also at hobbyking) sucks terribly, it induces BAD eddy currents in the motor, making it get really hot. And you'll need a controller that sends the right speed-control signal. Good luck!
KippTheKidd 1 year ago
Ive never seen such a tuff little motor! I want to get my hands on one of these to start my jet engine! Where do u get these motors?
stimps90 1 year ago
a brushless motor can last longer than a brushed one? it gets hot?
heberorozco 1 year ago
@heberorozco A brushless motor will last many, many times longer than a brushed motor. The only moving part is the bearing. They usually don't get as hot (for the same amount of power), so you can put lots more power in before worrying about it failing.
KippTheKidd 1 year ago
Cool.
Although I didn't see a lot of safety gear being employed...
You should be able to squeeze a lot out of those FET's with heat sinking. They work great for BLDC driving.
Those are some pretty good sized Electrolytics. Are you using them to suck up the back EMF for their next power on cycle?
Jim
QuantumDevices 1 year ago
@QuantumDevices With full heat sinking, those FETs can do >100 amps each. The switching rate in the video is 150KHz (I can run it up to 400Khz); the FETs turn on and off very quickly, which causes some pretty major spikes. The electrolytics are there to absorb that. The back EMF is clamped with diodes but is otherwise floating.
I think there are better options in terms of low ESR caps, but they're hard to find.
Check out the newer videos, the full circuit has 18 caps.
KippTheKidd 1 year ago
Very impressive!
ksandom40 1 year ago
Excellent setup !
You enhanced the amount of condensators to achieve higher power supply, right ?
What controller are you using & would you share your software ?
Great, weel done !
hoverpal 2 years ago
It is a custom controller and software. This may end up being a commercial endeavor, so I will not be sharing either, sorry!
The controller can operate sensorless (using back-EMF), with a pair of hall sensors, or with a 2-axis magnetometer. The theoretical limit of the circuit (with proper heat-sinks) is over 100kW... although realistically, I only expect to ever see 50kW out of it.
It's intended to run an ironless hub motor, which saves the whole issue of a chain and gearing.
KippTheKidd 2 years ago
well which software you use to controll speed
amarslove1 2 years ago
I wrote all of the software on the controller -- It's a custom set-up because I'm doing things for efficiency that nobody else does. The PC is just running a terminal program to send speed values (0-255) to the controller.
KippTheKidd 2 years ago
how do one measure the Volt on brushless dc, I cant with my normal meter
leviterande 2 years ago
You can't really measure the voltage across the wires in DC. You might be able to get a reading as AC, but it won't tell you anything useful.
The voltage I'm reading is across the battery -- Batteries fluctuate a lot when you're drawing power from them, so it's important to know how much they're really providing.
KippTheKidd 2 years ago
Sweet! Now you can make your own wind tunnel :). I find it hard to believe thet that tiny motor is acctually capable of handiling the current that would be going through its windings at 9 HP.. thats some where around 6,4 KW..and 6400 W / 24 V = 266 A... :O or is the motor designed for mutch higher voltage than you were using? But super awsome video!
paloperse 2 years ago
how do you make the driver i need to maek one
jomes31 3 years ago
wow that was a beast..but the guy on the sofa kinda rised his life..i mean if the prop would have broken free..it wud have gone straight for him..bt nevrthelss great vid
harshil69 3 years ago
If the prop broke free, since it is pushing air toward him, it would be pushed back towards me... Considering failure is not an option on airplanes, this propeller was definitely NOT going to break (It is a real aircraft propeller). What was more likely was one of the numerous papers or trinkets flying off the desk towards him!
Yeah, kinda stupid I guess, but it was a thrill!
KippTheKidd 3 years ago
neverthlss.!lovely vid HAHAH
harshil69 3 years ago
Awesome setup, but seriously, I wouldn't sit in front of propeller.....any catastrophic (unk unk) failure could result in someone's head getting sliced off!
Otherwise, WOW, lot of power!
UnderseaCaveman 3 years ago
nice lol
CupNoodles1 3 years ago
Sixth comment yay
Mykai73 3 years ago
Fifth comment yay
Mykai73 3 years ago
Fourth comment yay
Mykai73 3 years ago
Wow, what a great way to shoot stuff into Donny's face!
redlami 3 years ago
Niceeee... :)
frzsabet 3 years ago
This has been flagged as spam show
first comment yay
pokeabsol 3 years ago