One additional note is the early ESC had a opto sensor to synchronize the motor spin direction to the ESC control circuit.These were called "sensored" ESC units. Most today don't use this (some car ESC are still sold as sensored types). The sensoreless ones shown utilize the EMF filed that is generated by the motor windings and magnets, this signal gets processed and then used as a basic sync method to know where the motor shaft is during acceleration. This is the not the best way to do it, sometimes sensorless motors get what is called "cogging" due to the EMF signal not syncing up well.
All those FETs are setup in just 3 totem pole circuits. What happens is that one of the 3 totem pole outputs is set to go HIGH, and the other 2 are LOW. then the next totem pole is set to go HIGH, the the rest are set LOW. It cycles though all three and that is what makes the induction motor work.
I am new to RC, but not to electronics and for some time I wondered how ESCs worked. Given their low cost, I can see why most people buy them instead of make them. Very nice job keeping it simple, yet not to the point of inaccuracy.
This was a nice review. I had not ever considered cutting away part of the heat shrink for cooling purposes! Keep up the great efforts and respect from Apache Junction, Arizona
We also, strangely enough, pronounce half and calf omitting the L.Can't we all enjoy each others dialects and relish in the fact that we are able to communicate globally so easily now and share great knowledge and experiences?Thanks Bruce,really enjoy your vids! Happy Flying y'all !
Hi, I had trouble understanding the 3 wires coming out until a friend at my local hobby store told me that to reverse any two wires will reverse the motor. Then it clicked, these are nothing but 3 phase motors. Knowing that, I understood what the ESC is doing in replicating a public utilities electric generator (all are 3 phase). But instead of cycling between the phases at 60hz, it can be sped up or slowed down electronically. This technology is now used in HVAC to make super efficient airconditioner units by taking the AC current, turning it into DC and feeding it to an ESC to drive the 3 phase motors at a variable speed. This saves energy by never having to load up trying to compensate for an environment change in so many degrees.
These ESCs are not the same technology that is seen in large scale HVAC fan and pump motors. There aren't any "ESCs" on them. The Variable Frequency Drives or VFDs is what controls their speed. It does so by changing the frequency of the incoming AC voltage to the AC electric motor while the voltage stays constant. What is in our RC vehicles is a brushless DC motor which changes speed according to voltage and not frequency. What the Speed controller does is pulses a variable voltage between the 3 phases of the motor.
Correct, but the motors are 3 phase like the big industrial motors. However, they are powered (in the US) from 3 phase power at 60hz. An ESC can spin a motor much faster than that because it's computer driven to change the speed of the rotation between the legs of power. All the best and Happy flying!
Finaly a video not related to FPV nice to see this kind of information, it really helps us the new kids on the block to understand the science behind electric power. Thanks. How about one on how to use the GWS Servo tester and what is the meaning of all the adjustments and numbers.
@RCModelReviews you should also take into consideration, how fast does it take Hobby King customer service to answer an email or a phone, compared to Castle Creations service. That may have a huge affect on a price of the ESC. You get what you pay for.
nope, some of the fets are placed in parallel so they can achieve a required current rating. in this case there are 3 parallel fets placed in 6 groups required to achieve a 3 phase pushpull inverter bridge. the output (when connected to a motor) would have effectively 2 steps positive and 2 negative
That really explained so much-bl---- great video that has made me realize how it all works-one just gets an esc from HobbyKing as cheap- but to know what they do related to your motor and battery is crucial-Thank you!
Hi Bruce, Can you do a deeper technical video on this. I know you have a electronics back ground and I would like to have your opinion on some of the common ESC's from an electronics point of view. Most of them are based on the Atmega 8 and are easely flashable. I'm building a quad and got the 30A HK's (the ones with the blue wrapper) I flashed them with the SimonK firmware. The quad + camera is rather expensive and I would not want it to fail and crash because I was to cheap to by better ESC's. Thx!
thanks fett63 for your comments but i disagree about having more FPV. great video bruce. If i wanted to power a push bike as a concrete example what power controller and motor from hobbyking would youmsuggest and would it need a bec?:-)
Thanks Bruce, love the back to basics. One thing has always concerned me, some ESC's have coloured out puts but most are just all black. How import , or not, is connecting the ESC to the correct motor wire. I still live in the land of + & - , still don't fully understand how these new mortors work.
might be worth noting that all the linear BECs i have seen in the 2-4C range run 1A smd 7805 regulators in parallel. i believe the bec current rating advertised must be at the lowest number of operating cells because they are well under rated to dissipate the 6-10W (without heatsinking the 7805 as are all my ESC) needed for 3-4 cell operation at full current. other issue is i found 7805 directly parallel do not load share very well i find you usually get one that gets alot hotter than the rest.
I dont mean to be so off topic but does anybody know a trick to log back into an Instagram account..? I stupidly lost my login password. I appreciate any help you can give me.
@Jordy Judson I really appreciate your reply. I got to the site through google and Im trying it out atm. I see it takes a while so I will reply here later when my account password hopefully is recovered.
isnt it pulsed dc/pwm? i was under the understanding the polarity never reversed/ it never went bellow 0v.. you can get those fets cheap on ebay and 40-60 usd for a hot air rework station...cant recall if you had one, (thought i saw a rigol scope and the hakko station I wish i had bought...they left off a button on mine lol) im sure you are aware you could probably do it with just your iron as well.
I just crashed my Vision+ V3 so hard the poor phantom bounced twice and the battery went flying in the opposite direction. One ESC cracked in half, the body is shattered, the internal battery plug became unmounted and the motor was crushed. I was able to test and it still has power. The gimbal works and it also communicates with the vision app. However, when I tried starting the motors none of them spun. Of course I wouldn't expect the broken one to do anything but should that one ruined ESC and motor effect the other motors? Is this normal? I already ordered the body, a 2312 motor, an ESC v2.0 and an internal battery plug.
@Matthewandmatthewpwn almost correct, but not quite. "c" rating means how much more current (in Amps) the battery can provide than it has mAh. If you have a 1000 mAh battery it shpould be at least 40c to run 40a (1Ah*40c=40a) if you have a 5000 mAh battery and need 40 Amps it ought to be at least 8c rated (40A/5Ah=8c). And a 5000 mAh battery at 40c can provide as much as 200Amps of current. But having a bigger c rating puts less stress on the battery at the same current draw at the cost of mass.
hey, did you ever post the parts list of what you run in your axn?Im pretty new to the hobby, and it would help alot. thanks for the vids. there great.
wouldn't be able to point it out, but there is a small speaker, actually a piezo crystal on the controller someplace. that's what beeps. I suppose if you really wanted to, and if the motor was connected, you could make it beep too, by applying a DC signal to the motor at the frequency you wanted. It's called ferromagnetic resonance... that's why you hear transformers hum.
Fantastic...very nicely you have explained it. Sir, can you please clear a doubt of mine, that do PWM signal affects the activation of MOSFETs in ESC?? As what I was assuming till yesterday, that if we apply PWM signal for say forward then all the MOSFETs activated for carrying current and three phase switching will only vary as per the PWM signal value. But I got a weired problem with my Seaking HV130A ESC, that at 40% throttle value and 25A current consumption, the ESC got fried and when I asked the reason of this, I got the answer as the MOSFETs will open fully at 100% throttle only. And lesser throttle will partially open the MOSFETs and hence it generates more heat, consequently ESCs fried. So what is your opinion on this issue?
@adeptrc In this sense they indeed are AC (or alternating pulse DC to be more specific). But what i wanted to know is why for example CNC manufacturers are switching their from aternating pulse DC servo and "steppers" (which in essence are the same) to AC motor powered servo (induction (big machines) or synchronous based on magnets (smaller robotic arms) ). I still don't know what benefits has iduction/synchronous AC over pulse modulated DC?
A key think to know also is that ESC's have no reverse polarity protection so even a second of reverse polarity will try them. I learn this the expensive way when I killed all 4 esc's at once in my quad-copter.
Not the best idea to install 10A diode for racing/freestyle quadcopter power line where 80-140A current bursts are normal thing. From other side diode would be Ok for reverse polarity protection on workbench tests.
some people reverse their thrust upon landing in order to slow down the plane to making shorter landings, it's a cool concept. I think that's what he was talking about.
did i hear you say that the heat sink might fall off what there are not fastened down to the board ? have not opened one yet but have cut off some of the heat shrink off the around the heat sink
whats the little tan squares? has silver most time on each side? i have issue i see of mine burnt and esc turns off after a crash with tree branches but i dont wanna risk running if this is critical part its a dys xs20
where can I find the connection and function information on the 4 wire connector for the small ESCs that come on a Phantom 2. Also what is the current rating of it. I see no heat sinks on the FETS- is this a common failure mechanism
Cheers, I like your explanations of things. I would like to know if all BLDC ESC's can operate a PMDC brushed motor and what is or would be the best way to connect it. I know that some BLDC ESC's can, specifically Castle brand but I think that You need the Castle Link software to do it. Their instructions show the connections of the output wires having 2 of the 3 tied together and connected to the positive terminal of the brushes and the remaining output wire connected to the negative brush terminal. They were listed by color and I've forgotten which go to what connection. Any explanative help would be appreciated. I don't want to use a Castle controller if I don't have to.
Thanks for the awesome info A few questions if I may .. I have a speed controller with two smaller capacitors on the board with a common earth as well as the two big ones. I've replaced the big ones as one blew. And both the small ones as They were rusty. The speed controller still doesn't work. Is this likey to be the fets ? Why would my one large capacitor have blown ? Thanks so much in advance
i need a esc to turn a 24 volt 6s rc turbine i purchased to make a fan with. i would like to replace the receiver with a basic knob. can you post links for a inexpensive esc and speed controller? please,thank you.
Great video! I never thought about converting DC and AC power. I'm not sure if you have any experience but could you do a video on how to rewind a brushless motor?
hello Bruce Thank you for the great info. Im new to electric powered rc and recently bought a trex700 I poped the esc open and sodered new leads to make them longer I didnt relize the motor was ac and now ive relized since I dont have a O Scope im not going to be able to test it what should I do. thank you mb
Are their any Silicon Carbide transistors available to replace the Silicon Transistors? Sure they cost a lot more, but they would make the controller much smaller!
OR, it could be that throttle position determines duty cycle, and the resultant RPM is whatever the ESC senses is the correct RPM for the given commanded duty cycle and the load. Is this the correct understanding of what ESCs do with the commanded throttle position?
I am interested in running a two motored craft . I am interested in them running on opposite directions ( 1 ) I see no reason that the motor element will not cope with this process ? ( 2 ) is it possible to get the controllers to put out the required power just by reversing the wiring from the ESC ?
How does esc now motor position to apply voltage to coils (basically where is the feedback to keep the rotor and state in-sync? On DC brushed motor its physical position between brushes and comutator (I don't know if that correct terminology and spelling) to know when to power next set of coils. Is it detecting voltage through unpowered coil while other are getting power at that instant? Ex 1 2 on 3 off, 1 3 on 2 off, and so on? And is the signal into esc (from flight controller or receiver) just varying voltage or pulse frequency to tell esc whether to speed up or slow down motor? I am assuming esc doesn't provide feedback to controller or receiver. Yeah I know recently receiver controller an esc for servo. Controller controls esc In application such as quadcopter motors.
@noelywire Also more expensive ESC's have smoother throttle curve and generally are more reliable. They also have so functions like governor (to keep constant head speed for helicopters). But for not so expensive models cheap ESC's are great!
I always taught that you only need to switch two motor wires to reverse the motor spin direction, or am I wrong? Have not done that myself yet though. Seams like a overkill to reflash the microcontroller.
Great video, from your videos I understand selecting the right ESC and what motor, ESC and battery can be paired up, but do you have any videos with the equations behind selecting the optimal engine, prop and battery for a fixed wing EPP plane?
Had to pause the video about 100 times to find what I wanted to see, which was the capacity of those big capacitors. Looks like 330uF. Not the biggest available, which makes me wonder if improvements could be made by adding capacitance to a board for more zoom-zoom.
Thankyou for the informative video, I have an ESC a friend donated to my collection and I noticed that it gets warm not HOT just warm with no juice going threw, just being connected to the battery. Is this normal?
KV = 1000rpm/Vrms example: 1700kv bldc, the motor will rotate 1700rpm per 1V. so if the supply is 10V, simply multiple the rpm with 10 and you get the rpm. or you can google article about kv rating of bldc motor. Thera are alot of explanation out there.
Hello my friend, I have bought an ESC for forward and reverse and brake. can i change him to go forward only? his proper programming card doesn't have this option unfortunately....is there anything that can be done to do this? thanks, if you can answer me..
FIRE!!! well... white smoke at least... I am running naze32 full board with afro esc 12 amp flashed with BLheli on DYS be1806 2300KV Motors. as soon as I plug in power the motor that is connected to the ESC that powers the Naze starts to smoke. I have motor stop enabled. the Naze still works. I ordered new motors and as soon as I powered up again... White Smoke from the new motor... please advise. Software issue? dead ESC? Is there a simple test I can perform? thanks in advance!
The esc shootout sounds great. I'd love to see a shootout between super cheap like the ss, proven escs like the plush and high end ones like cc, scorpion ect.
I have an unlabeled ESC that looks identical to the one in your initial thumb image. I'm trying to figure out how to program the brake. Can you tell me what model that is or how to program the brake on it?
great vid! I have a hubsan h501s that I transferred all the components to a f330 frame and It uses 12 amp esc (just had one burn out), I'm trying to figure out if i could use a alternate esc besides the oem? Also could I even go higher amp and diff motors?
About the comment that people are flashing the on board microcontroller of their ESC to reverse the motor direction. That is not necessary, provided it is a 3-phase motor/ESC (you'll have 3 wires going to the motor). In this case all you have to do is swap any 2 of the wires going from the ESC to the motor. This is a simple principle of 3phase electrical theory/practice.
thanks for your review ,what can i do for not burning more esc , i match lipo battery current with motor and esc ,i use my esc in boats ,i am very careful to have adequate cooling and not too big props otherwise they draw more current and burn ,but whatever i do they also burn sooner or later .i normally use cheap esc like hobbyking,i m afraid to buy an expensive esc coz i ll be afraid to burnt it also
Hobbyking have told me the ESC's on thier out the box quad (BlackWidow260) are 20a, however I dont think they are! I dont understand how they can sell a product and not be able to confirm what ESC are on it :( anyone know?
If I have two identical sets of battery, ESC, and motor, and I put on different sized propellers on them, then how does (1) power output, and (2) RPM vary according to throttle position? I am under the impression that both setups will give the same RPM at the same throttle positions, (and power output is greater in the setup that has the bigger prop). Is this correct? i.e. at say 90% throttle position in both set ups, both props would be spinning at the same RPM?
Do you think that a battery really benefits from the capacitors? I always assumed the capacitors were there to make life easier on the regulator that feeds the other electronics...especially the RX. Wouldn't the series inductance from the wires and the battery's internals alone keep it from seeing spikes? What do you think? Would a battery get hotter without them?
I want to replace the MOSFETs in my mamba phoenix rated for 50v 160a continuous. I need an ESC that can output 30v at 400a. I was wondering how feasible it would be to Replace each MOSFET with ones that can handle 30v (instead of 50). another thing I saw online were stacking MOSFETs on top of each other.... i already made an enormous cap pack using 6 35v 4700f (in parallel) so replacing the MOSFETs looks like it would be harder than stacking an extra one right on top.. oh and I'm going to use 2 larger cooling fans along with the stock heatsink. any suggestions?.... my brush less motor is rated for 25v 350a continuous; something like 7200w. (200km/h+ 1/8 rc car)
Does the ESC maintain a fixed RPM at a specific Throttle setting? What happens if the propellar spins faster than that RPM? Will the motor be commanded by the ESC to slow down? Does the Throttle setting control fixed RPM or Fixed Wattage or Fixed Voltage or Fixed Current? Which one?
Hi Bruce: Had a crash with my Heli and now my 35Amp ESC is not working. What would be the proceedure to confirm that the ESC is broken and if it is, would there be a method to fix it?
How do these RC ESC know the position of the rotor ? No doubt it is through back emf sensing but how do they actually do it ? Are they doing zero crossing sensing on the inactive coil ? Do they sense zero crossing only on one phase or on all three phases ? What is the exact microcontroller on these boards ? Are they general purpose uC or specialized for this application ? How are the outputs ? Are they pwm driving the motors or do they do a single pulse per turn on each phase ?
+shodanxx Yes, they detect rotor position through back-emf sensing on the undriven phase. When the motor starts from a standstill, the ESC feeds it a canned commutation sequence to kick the rotor over fast enough to acquire a back emf signal. Thats' why sensorless ESCs won't start a motor smoothly at very low power and RPM, and it's also why they suck for low-RPM high-torque applications, because at high currents the switching noise on the coils messes with the faint back emf signal, and 'confuses' the ESC. For traction applications i.e. electric bikes & skateboards, large heavy RC cars etc. a sensored ESC is better because rotor position sensing is independent of back-emf signal strength and is unaffected by power switching noise. The microcontrollers, as I understand, are general purpose units and are very inexpensive. The software for sensing and noise filtering of the back-emf rotor position signal is mighty clever though! The outputs drive the motor using PWM for throttle control. On many ESC types, the PWM rate can be selected by the user. Same with the lead angle, which they often refer to as 'timing'.
shodanxx You sample the adc mid pwm pulse when signal is stabilized. Your zero is sum of all emf voltages and on the dangling coil the voltage is 0 to vemf range so it is not an ac current making it easy to sample directly on the uc using just a resistor voltage divider to step down the voltage to adc levels.
the motors have 3 channels corresponding to the 3 output wires from the esc, these are positive,ground and open. When the magnets inside the motor pass through the open terminal the impedance sky rockets and makes it possible to know exactly when the magnet is in the center of the open terminal, once this is detected, the terminals are changed to pull the motor around to the next stage and this cycle continues.
What are the 3 IGBT on the Microcontroller side for? right side, opposite to the DCDC (UBEC). I opened a citrix stock spec car controller and it looks similar to this one with an ATmega and those 3 IGBTs on the right side.
+Mathieu Bacquet this is not an IGBT these are the FETs drivers high and low side drivers they use to control the FETs to supply the motor with power in its right sequence.
@cynr100 brushless motors are driven by 3 phase AC current. there is no difference in how you connect these 3 wires) If the motor turns backwards you just reverse 2 of them. For example if you plug wires like 1-2-3 and it goes th wrong way - hust plug them in 2-1-3 order. You can read more on motors on Wiki: en (dot) wikipedia (dot) org/wiki/Brushless_DC_electric_motor
Can you hook up an normal dc motor to the ESC? The one with only two wires? Or do you absolutely need a 3 phase motor. Just getting into the hobby myself.
hi there, i have a question regarding esc wire length. some RCgroups topics are talking about maximum lenght (about 20 to 30cm) and never go longer some are talking about never touch power wire and add lenght to 3 wires that goes to motor some are talking that if you go above 30cm of wire, you have to add capacitors on power wires, and eventually add other every 20cms effectively, some companies (YGE, Castle, Schulze....) are selling kits with extra capacitors. What's you technical advise on that ?
The correct answer is smoke. The chinese smoke manufacturers fit plenty of smoke into these devices, if it happens to fail, it is due to a lack of smoke, which becomes quite apparent due to the new exterior location of all of said smoke.
One additional note is the early ESC had a opto sensor to synchronize the motor spin direction to the ESC control circuit.These were called "sensored" ESC units. Most today don't use this (some car ESC are still sold as sensored types). The sensoreless ones shown utilize the EMF filed that is generated by the motor windings and magnets, this signal gets processed and then used as a basic sync method to know where the motor shaft is during acceleration. This is the not the best way to do it, sometimes sensorless motors get what is called "cogging" due to the EMF signal not syncing up well.
Thanks, I have spent days trying to understand an ESC, an you have done it in 7 min's, well done
All those FETs are setup in just 3 totem pole circuits. What happens is that one of the 3 totem pole outputs is set to go HIGH, and the other 2 are LOW. then the next totem pole is set to go HIGH, the the rest are set LOW. It cycles though all three and that is what makes the induction motor work.
I am new to RC, but not to electronics and for some time I wondered how ESCs worked. Given their low cost, I can see why most people buy them instead of make them. Very nice job keeping it simple, yet not to the point of inaccuracy.
This was a nice review. I had not ever considered cutting away part of the heat shrink for cooling purposes! Keep up the great efforts and respect from Apache Junction, Arizona
We also, strangely enough, pronounce half and calf omitting the L.Can't we all enjoy each others dialects and relish in the fact that we are able to communicate globally so easily now and share great knowledge and experiences?Thanks Bruce,really enjoy your vids! Happy Flying y'all !
Hi, I had trouble understanding the 3 wires coming out until a friend at my local hobby store told me that to reverse any two wires will reverse the motor. Then it clicked, these are nothing but 3 phase motors. Knowing that, I understood what the ESC is doing in replicating a public utilities electric generator (all are 3 phase). But instead of cycling between the phases at 60hz, it can be sped up or slowed down electronically. This technology is now used in HVAC to make super efficient airconditioner units by taking the AC current, turning it into DC and feeding it to an ESC to drive the 3 phase motors at a variable speed. This saves energy by never having to load up trying to compensate for an environment change in so many degrees.
These ESCs are not the same technology that is seen in large scale HVAC fan and pump motors. There aren't any "ESCs" on them. The Variable Frequency Drives or VFDs is what controls their speed. It does so by changing the frequency of the incoming AC voltage to the AC electric motor while the voltage stays constant. What is in our RC vehicles is a brushless DC motor which changes speed according to voltage and not frequency. What the Speed controller does is pulses a variable voltage between the 3 phases of the motor.
Correct, but the motors are 3 phase like the big industrial motors. However, they are powered (in the US) from 3 phase power at 60hz. An ESC can spin a motor much faster than that because it's computer driven to change the speed of the rotation between the legs of power. All the best and Happy flying!
Wow, great job. you have a pleasing and proper voice for these vids. well done sir!
From DC to AC! Duh, now I understand the 3 wires and the fact that they can be connected in different positions. Thanks for that mate.
My knowledge of these beasts has just taken a quantum leap thanks to you very clear video ;-)
i am watching you from years , you are a great passionate person and make very helpful videos.
keep going
"Fitz" = MOSFETS
(To avoid confusion)
Thanks for the video.
Hi Bruce was wondering if you would show us how to repair the capacitors and where exactly to solder them on the board thanks keep them coming
Pretty sure that round thing you pointed at @3:55 is an inductor (coil).
FET=Field effect transistor
Finaly a video not related to FPV nice to see this kind of information, it really helps us the new kids on the block to understand the science behind electric power. Thanks.
How about one on how to use the GWS Servo tester and what is the meaning of all the adjustments and numbers.
It is also good to mount the ESC in a way where it will get airflow for cooling if possible.
@gluino the setup with the lesser prop will be spinning faster and with a
lower current draw.
@RCModelReviews
you should also take into consideration, how fast does it take Hobby King customer service to answer an email or a phone, compared to Castle Creations service. That may have a huge affect on a price of the ESC. You get what you pay for.
nope, some of the fets are placed in parallel so they can achieve a required current rating. in this case there are 3 parallel fets placed in 6 groups required to achieve a 3 phase pushpull inverter bridge. the output (when connected to a motor) would have effectively 2 steps positive and 2 negative
I think it switches them all in parallel, meaning each individual FET handles a sixth of the full current - sharing the load
That really explained so much-bl---- great video that has made me realize how it all works-one just gets an esc from HobbyKing as cheap- but to know what they do related to your motor and battery is crucial-Thank you!
Hi Bruce,
Can you do a deeper technical video on this. I know you have a electronics back ground and I would like to have your opinion on some of the common ESC's from an electronics point of view. Most of them are based on the Atmega 8 and are easely flashable. I'm building a quad and got the 30A HK's (the ones with the blue wrapper) I flashed them with the SimonK firmware. The quad + camera is rather expensive and I would not want it to fail and crash because I was to cheap to by better ESC's.
Thx!
thanks fett63 for your comments but i disagree about having more FPV. great video bruce. If i wanted to power a push bike as a concrete example what power controller and motor from hobbyking would youmsuggest and would it need a bec?:-)
Awesome video. Have always wondered whats inside but havent broke anyone yet so havent had the chanse to open :) Thank you
Thanks Bruce, love the back to basics. One thing has always concerned me, some ESC's have coloured out puts but most are just all black. How import , or not, is connecting the ESC to the correct motor wire. I still live in the land of + & - , still don't fully understand how these new mortors work.
might be worth noting that all the linear BECs i have seen in the 2-4C range run 1A smd 7805 regulators in parallel. i believe the bec current rating advertised must be at the lowest number of operating cells because they are well under rated to dissipate the 6-10W (without heatsinking the 7805 as are all my ESC) needed for 3-4 cell operation at full current. other issue is i found 7805 directly parallel do not load share very well i find you usually get one that gets alot hotter than the rest.
Thank you for doing such a good job on your videos! It's nice to have someone explain this in the detail that I need! Your videos are invaluable!
I dont mean to be so off topic but does anybody know a trick to log back into an Instagram account..?
I stupidly lost my login password. I appreciate any help you can give me.
@Jorge Kane instablaster ;)
@Jordy Judson I really appreciate your reply. I got to the site through google and Im trying it out atm.
I see it takes a while so I will reply here later when my account password hopefully is recovered.
@Jordy Judson it did the trick and I actually got access to my account again. Im so happy:D
Thanks so much you really help me out !
@Jorge Kane Glad I could help =)
isnt it pulsed dc/pwm? i was under the understanding the polarity never reversed/ it never went bellow 0v.. you can get those fets cheap on ebay and 40-60 usd for a hot air rework station...cant recall if you had one, (thought i saw a rigol scope and the hakko station I wish i had bought...they left off a button on mine lol) im sure you are aware you could probably do it with just your iron as well.
hey bruce, any chance you could make a video on where to place ferrite rings on a rc model plane, particularly a fpv plane? would love that!
I just crashed my Vision+ V3 so hard the poor phantom bounced twice and the battery went flying in the opposite direction. One ESC cracked in half, the body is shattered, the internal battery plug became unmounted and the motor was crushed. I was able to test and it still has power. The gimbal works and it also communicates with the vision app. However, when I tried starting the motors none of them spun. Of course I wouldn't expect the broken one to do anything but should that one ruined ESC and motor effect the other motors? Is this normal? I already ordered the body, a 2312 motor, an ESC v2.0 and an internal battery plug.
good info Bruce, keep the how it works segment going.
@Matthewandmatthewpwn almost correct, but not quite. "c" rating means how much more current (in Amps) the battery can provide than it has mAh. If you have a 1000 mAh battery it shpould be at least 40c to run 40a (1Ah*40c=40a) if you have a 5000 mAh battery and need 40 Amps it ought to be at least 8c rated (40A/5Ah=8c). And a 5000 mAh battery at 40c can provide as much as 200Amps of current. But having a bigger c rating puts less stress on the battery at the same current draw at the cost of mass.
hey, did you ever post the parts list of what you run in your axn?Im pretty new to the hobby, and it would help alot. thanks for the vids. there great.
Thanks for the video, very educational and clear. You also have the perfect narrating voice for this type of video - keep up the good work :-)
Great videos. Have you done a video on properly matching your motor, ESC and battery?
Great video 👌🏻
wouldn't be able to point it out, but there is a small speaker, actually a piezo crystal on the controller someplace. that's what beeps. I suppose if you really wanted to, and if the motor was connected, you could make it beep too, by applying a DC signal to the motor at the frequency you wanted. It's called ferromagnetic resonance... that's why you hear transformers hum.
Fantastic...very nicely you have explained it.
Sir, can you please clear a doubt of mine, that do PWM signal affects the activation of MOSFETs in ESC?? As what I was assuming till yesterday, that if we apply PWM signal for say forward then all the MOSFETs activated for carrying current and three phase switching will only vary as per the PWM signal value. But I got a weired problem with my Seaking HV130A ESC, that at 40% throttle value and 25A current consumption, the ESC got fried and when I asked the reason of this, I got the answer as the MOSFETs will open fully at 100% throttle only. And lesser throttle will partially open the MOSFETs and hence it generates more heat, consequently ESCs fried. So what is your opinion on this issue?
@adeptrc
In this sense they indeed are AC (or alternating pulse DC to be more specific).
But what i wanted to know is why for example CNC manufacturers are switching their from aternating pulse DC servo and "steppers" (which in essence are the same) to AC motor powered servo (induction (big machines) or synchronous based on magnets (smaller robotic arms) ).
I still don't know what benefits has iduction/synchronous AC over pulse modulated DC?
in fact, they are dc motors but controlled in 6 steps with pwm signal
Hey Bruce, what are these three SMT 8 legs chips next to motor wires? FET drivers I guess?
A key think to know also is that ESC's have no reverse polarity protection so even a second of reverse polarity will try them. I learn this the expensive way when I killed all 4 esc's at once in my quad-copter.
Harsh. Well you will never do it again now
Hi, just a Idea could you put a 10A diode in the power side to stop the reverse current from blowing the esc out?
Ivan G-S how did you do that unless you hooked a battery to 2 of the 3 wires on the other side, the side that the motor connects too
Not the best idea to install 10A diode for racing/freestyle quadcopter power line where 80-140A current bursts are normal thing. From other side diode would be Ok for reverse polarity protection on workbench tests.
some people reverse their thrust upon landing in order to slow down the plane to making shorter landings, it's a cool concept. I think that's what he was talking about.
did i hear you say that the heat sink might fall off
what there are not fastened down to the board ?
have not opened one yet
but have cut off some of the heat shrink off
the around the heat sink
I have an ESC where one of the IGBT driver chips failed. Not any of the MOSFETs.
Looks the ESC generates a 3 phase signal. I was wondering where is the ground then, which would need 4 wires. Right?
whats the little tan squares? has silver most time on each side? i have issue i see of mine burnt and esc turns off after a crash with tree branches but i dont wanna risk running if this is critical part its a dys xs20
where can I find the connection and function information on the 4 wire connector for the small ESCs that come on a Phantom 2. Also what is the current rating of it. I see no heat sinks on the FETS- is this a common failure mechanism
Hi Bruce. whats a good way to attach a heatsink to those fets?
Cheers, I like your explanations of things. I would like to know if all BLDC ESC's can operate a PMDC brushed motor and what is or would be the best way to connect it. I know that some BLDC ESC's can, specifically Castle brand but I think that You need the Castle Link software to do it. Their instructions show the connections of the output wires having 2 of the 3 tied together and connected to the positive terminal of the brushes and the remaining output wire connected to the negative brush terminal. They were listed by color and I've forgotten which go to what connection. Any explanative help would be appreciated. I don't want to use a Castle controller if I don't have to.
Another informative video, and another great job buddy! Keep em' coming.
Thanks for the awesome info
A few questions if I may ..
I have a speed controller with two smaller capacitors on the board with a common earth as well as the two big ones.
I've replaced the big ones as one blew. And both the small ones as They were rusty.
The speed controller still doesn't work.
Is this likey to be the fets ?
Why would my one large capacitor have blown ?
Thanks so much in advance
When we connect the battery to the ESC..there will be the beep sound..but where the beep sound actually come from?
i need a esc to turn a 24 volt 6s rc turbine i purchased to make a fan with. i would like to replace the receiver with a basic knob. can you post links for a inexpensive esc and speed controller? please,thank you.
Great video! I never thought about converting DC and AC power. I'm not sure if you have any experience but could you do a video on how to rewind a brushless motor?
Thank you for one more informative video, Bruce
Nice vid. Im familiar with a few of those components but i now look at my esc's like they are alot more complex besides what they do.
hello Bruce Thank you for the great info. Im new to electric powered rc and recently bought a trex700 I poped the esc open and sodered new leads to make them longer I didnt relize the motor was ac and now ive relized since I dont have a O Scope im not going to be able to test it what should I do. thank you mb
Great video Bruce. Keep them coming, can you do a video on brushless motors? What all the ratings mean, how to find out how many polls ect..
Are their any Silicon Carbide transistors available to replace the Silicon Transistors? Sure they cost a lot more, but they would make the controller much smaller!
OR, it could be that throttle position determines duty cycle, and the resultant RPM is whatever the ESC senses is the correct RPM for the given commanded duty cycle and the load.
Is this the correct understanding of what ESCs do with the commanded throttle position?
I am interested in running a two motored craft . I am interested in them running on opposite directions ( 1 ) I see no reason that the motor element will not cope with this process ? ( 2 ) is it possible to get the controllers to put out the required power just by reversing the wiring from the ESC ?
How does esc now motor position to apply voltage to coils (basically where is the feedback to keep the rotor and state in-sync? On DC brushed motor its physical position between brushes and comutator (I don't know if that correct terminology and spelling) to know when to power next set of coils. Is it detecting voltage through unpowered coil while other are getting power at that instant? Ex 1 2 on 3 off, 1 3 on 2 off, and so on?
And is the signal into esc (from flight controller or receiver) just varying voltage or pulse frequency to tell esc whether to speed up or slow down motor? I am assuming esc doesn't provide feedback to controller or receiver. Yeah I know recently receiver controller an esc for servo. Controller controls esc In application such as quadcopter motors.
@noelywire Also more expensive ESC's have smoother throttle curve and generally are more reliable. They also have so functions like governor (to keep constant head speed for helicopters). But for not so expensive models cheap ESC's are great!
I always taught that you only need to switch two motor wires to reverse the motor spin direction, or am I wrong? Have not done that myself yet though. Seams like a overkill to reflash the microcontroller.
Great video, from your videos I understand selecting the right ESC and what motor, ESC and battery can be paired up, but do you have any videos with the equations behind selecting the optimal engine, prop and battery for a fixed wing EPP plane?
Is cause of board failure attributed to FET, MOSFET, resistor, cap or other discrete component and rarely affects the chipset itself?
Had to pause the video about 100 times to find what I wanted to see, which was the capacity of those big capacitors. Looks like 330uF. Not the biggest available, which makes me wonder if improvements could be made by adding capacitance to a board for more zoom-zoom.
Thankyou for the informative video, I have an ESC a friend donated to my collection and I noticed that it gets warm not HOT just warm with no juice going threw, just being connected to the battery. Is this normal?
Great video! One question though: How can regenerative braking be programmed?
KV = 1000rpm/Vrms
example: 1700kv bldc, the motor will rotate 1700rpm per 1V. so if the supply is 10V, simply multiple the rpm with 10 and you get the rpm. or you can google article about kv rating of bldc motor. Thera are alot of explanation out there.
Why would you need to "Flash" the esc to make the motor spin backwards when you can just
swap 2 of the motor wires around?
Hello my friend, I have bought an ESC for forward and reverse and brake. can i change him to go forward only? his proper programming card doesn't have this option unfortunately....is there anything that can be done to do this? thanks, if you can answer me..
So who writes the firmware for these ESCs? Is it HK/Turnigy/Hextronik?
Any links to any custom firmware projects for them?
Thanks for the vid.
FIRE!!! well... white smoke at least... I am running naze32 full board with afro esc 12 amp flashed with BLheli on DYS be1806 2300KV Motors. as soon as I plug in power the motor that is connected to the ESC that powers the Naze starts to smoke. I have motor stop enabled. the Naze still works. I ordered new motors and as soon as I powered up again... White Smoke from the new motor... please advise. Software issue? dead ESC? Is there a simple test I can perform? thanks in advance!
Which microcontroller is used in the ESC shown in the video ?
The esc shootout sounds great. I'd love to see a shootout between super cheap like the ss, proven escs like the plush and high end ones like cc, scorpion ect.
I have an unlabeled ESC that looks identical to the one in your initial thumb image. I'm trying to figure out how to program the brake. Can you tell me what model that is or how to program the brake on it?
I got an blackfoot rc for my son, it was the mechanical control. I want to bring it up to date. I need a cheap esc with bec, what would you do.
Hi, how different is an esc from a what you have shown here to an esc that is in a brushless cordless drill?
great vid! I have a hubsan h501s that I transferred all the components to a f330 frame and It uses 12 amp esc (just had one burn out), I'm trying to figure out if i could use a alternate esc besides the oem? Also could I even go higher amp and diff motors?
What kind of control signal is sent to esc? Is it a DC voltage and frequency is proportional to DC voltage is it it an oscillating signal?
About the comment that people are flashing the on board microcontroller of their ESC to reverse the motor direction. That is not necessary, provided it is a 3-phase motor/ESC (you'll have 3 wires going to the motor). In this case all you have to do is swap any 2 of the wires going from the ESC to the motor. This is a simple principle of 3phase electrical theory/practice.
thanks for your review ,what can i do for not burning more esc , i match lipo battery current with motor and esc ,i use my esc in boats ,i am very careful to have adequate cooling and not too big props otherwise they draw more current and burn ,but whatever i do they also burn sooner or later .i normally use cheap esc like hobbyking,i m afraid to buy an expensive esc coz i ll be afraid to burnt it also
Hobbyking have told me the ESC's on thier out the box quad (BlackWidow260) are 20a, however I dont think they are! I dont understand how they can sell a product and not be able to confirm what ESC are on it :( anyone know?
Robert Slackware Ford cars made in Mexico are made in America. The Americas consist of a lot more than just the USA.
If I have two identical sets of battery, ESC, and motor, and I put on different sized propellers on them, then how does (1) power output, and (2) RPM vary according to throttle position?
I am under the impression that both setups will give the same RPM at the same throttle positions, (and power output is greater in the setup that has the bigger prop). Is this correct?
i.e. at say 90% throttle position in both set ups, both props would be spinning at the same RPM?
I'd like to know your thoughts on expensive escs v inexpensive ones. Why are expensive ones, expensive? Are they ever worth the money?
If I have a 40a esc do I need a higher 40c discharge battery to cope with it or will the battery have to much power being pulled out of it?
Do you think that a battery really benefits from the capacitors? I always assumed the capacitors were there to make life easier on the regulator that feeds the other electronics...especially the RX. Wouldn't the series inductance from the wires and the battery's internals alone keep it from seeing spikes? What do you think? Would a battery get hotter without them?
sorry for being 10 years to late but they are to filter the power llines cause of spikes of the motor
I want to replace the MOSFETs in my mamba phoenix rated for 50v 160a continuous. I need an ESC that can output 30v at 400a. I was wondering how feasible it would be to Replace each MOSFET with ones that can handle 30v (instead of 50).
another thing I saw online were stacking MOSFETs on top of each other.... i already made an enormous cap pack using 6 35v 4700f (in parallel) so replacing the MOSFETs looks like it would be harder than stacking an extra one right on top.. oh and I'm going to use 2 larger cooling fans along with the stock heatsink. any suggestions?.... my brush less motor is rated for 25v 350a continuous; something like 7200w. (200km/h+ 1/8 rc car)
Does the ESC maintain a fixed RPM at a specific Throttle setting? What happens if the propellar spins faster than that RPM? Will the motor be commanded by the ESC to slow down? Does the Throttle setting control fixed RPM or Fixed Wattage or Fixed Voltage or Fixed Current? Which one?
i am going to use 2600 mah 14.8v 40c ,, with 40 amp esc ,,, i am afraid i might burn it ,,,,, do you think its a good idea ,, please reply me ,, thnx
Hi Bruce: Had a crash with my Heli and now my 35Amp ESC is not working.
What would be the proceedure to confirm that the ESC is broken and if it is, would there be a method to fix it?
How do these RC ESC know the position of the rotor ? No doubt it is through back emf sensing but how do they actually do it ? Are they doing zero crossing sensing on the inactive coil ? Do they sense zero crossing only on one phase or on all three phases ?
What is the exact microcontroller on these boards ? Are they general purpose uC or specialized for this application ?
How are the outputs ? Are they pwm driving the motors or do they do a single pulse per turn on each phase ?
+shodanxx
Yes, they detect rotor position through back-emf sensing on the undriven phase. When the motor starts from a standstill, the ESC feeds it a canned commutation sequence to kick the rotor over fast enough to acquire a back emf signal. Thats' why sensorless ESCs won't start a motor smoothly at very low power and RPM, and it's also why they suck for low-RPM high-torque applications, because at high currents the switching noise on the coils messes with the faint back emf signal, and 'confuses' the ESC. For traction applications i.e. electric bikes & skateboards, large heavy RC cars etc. a sensored ESC is better because rotor position sensing is independent of back-emf signal strength and is unaffected by power switching noise.
The microcontrollers, as I understand, are general purpose units and are very inexpensive. The software for sensing and noise filtering of the back-emf rotor position signal is mighty clever though!
The outputs drive the motor using PWM for throttle control. On many ESC types, the PWM rate can be selected by the user. Same with the lead angle, which they often refer to as 'timing'.
shodanxx You sample the adc mid pwm pulse when signal is stabilized. Your zero is sum of all emf voltages and on the dangling coil the voltage is 0 to vemf range so it is not an ac current making it easy to sample directly on the uc using just a resistor voltage divider to step down the voltage to adc levels.
the motors have 3 channels corresponding to the 3 output wires from the esc, these are positive,ground and open. When the magnets inside the motor pass through the open terminal the impedance sky rockets and makes it possible to know exactly when the magnet is in the center of the open terminal, once this is detected, the terminals are changed to pull the motor around to the next stage and this cycle continues.
Josh Brown impedance is of no interest at all. It is never measured. Don't confuse people.
Excellent and Clear explanation. Sure you are a basement engineer. ?
What are the 3 IGBT on the Microcontroller side for? right side, opposite to the DCDC (UBEC). I opened a citrix stock spec car controller and it looks similar to this one with an ATmega and those 3 IGBTs on the right side.
+Mathieu Bacquet this is not an IGBT these are the FETs drivers high and low side drivers they use to control the FETs to supply the motor with power in its right sequence.
@cynr100 brushless motors are driven by 3 phase AC current. there is no difference in how you connect these 3 wires) If the motor turns backwards you just reverse 2 of them. For example if you plug wires like 1-2-3 and it goes th wrong way - hust plug them in 2-1-3 order. You can read more on motors on Wiki: en (dot) wikipedia (dot) org/wiki/Brushless_DC_electric_motor
Can you hook up an normal dc motor to the ESC? The one with only two wires? Or do you absolutely need a 3 phase motor. Just getting into the hobby myself.
Great vid. Thanks. Is your esc under the same stress whether its running full throttle or partial throttle?
hi there, i have a question regarding esc wire length.
some RCgroups topics are talking about maximum lenght (about 20 to 30cm) and never go longer
some are talking about never touch power wire and add lenght to 3 wires that goes to motor
some are talking that if you go above 30cm of wire, you have to add capacitors on power wires, and eventually add other every 20cms
effectively, some companies (YGE, Castle, Schulze....) are selling kits with extra capacitors. What's you technical advise on that ?
What's inside ESC's? The Magic Smoke of course!
The correct answer is smoke. The chinese smoke manufacturers fit plenty of smoke into these devices, if it happens to fail, it is due to a lack of smoke, which becomes quite apparent due to the new exterior location of all of said smoke.