RC Basics - Understanding Electronic Speed Controllers (ESC)
Summary
TLDRIn this video, we explore electronic speed controllers (ESCs), explaining their function in running motors and supplying voltage to flight controllers and other electronics. Key topics include how ESCs work, their three-wire connections, motor control, firmware options (Simon K, BL Heli), and calibration. We also cover brake, throttle response, timing, and battery eliminator circuits (BECs). This video aims to demystify ESCs and provide enough context for viewers to further their research. It's a comprehensive guide for enthusiasts looking to understand and optimize their models' performance.
Takeaways
- 😀 Electronic Speed Controllers (ESCs) are essential for running motors and supplying power to flight controllers and other electronics.
- 🔧 ESCs have three wires because they control three-phase brushless motors, which require a specific sequence of power to function correctly.
- 📡 ESCs can be set up with various configurations, including brake, throttle response, and timing, which can affect motor performance.
- 🛠 Firmware versions like SimonK and BLHeli are specialized for multirotors, offering faster response times and better motor control.
- 🔄 Swapping any two of the three motor wires can reverse the motor's direction, which is a quick fix if the motor is spinning the wrong way.
- 🚫 Traditional ESC settings like 'brake' and 'low voltage alarm' may not be suitable for all applications, such as multirotors.
- 🔄 ESCs with a bootloader make it easier to change firmware, allowing for customization of motor control characteristics.
- 📶 One-shot ESCs offer an 8-megahertz update speed for motor control, providing faster and more instant response times than traditional 1-megahertz signals.
- 🔄 Throttle calibration is crucial for ensuring that the ESC understands the throttle range of the radio or flight controller, preventing motor misbehavior.
- 🔌 Battery Eliminator Circuits (BECs) provide +5 volts to the flight controller and servos, with different types like linear, switched, and Optio offering varying levels of efficiency and functionality.
- ⚠️ High-power ESCs may not include a BEC, requiring a separate power source for the flight controller and other electronics.
Q & A
What are the two basic functions of an Electronic Speed Controller (ESC)?
-The two basic functions of an ESC are to run a motor and, in many cases, to supply the +5 volts needed for flight controllers, servos, and other electronics in the craft to operate.
Why are there three wires coming out of an ESC instead of the usual two (black and red)?
-There are three wires because the ESC is connected to a three-phase brushless motor, with each wire connecting to one of the three phases of the motor.
How does an ESC control the speed of a motor?
-An ESC controls the speed of a motor by firing pairs of wires connected to electromagnets in the motor in rapid succession, which in turn rotates the motor's rotor. The ESC also listens to feedback from the motor to know where to fire the next electromagnet.
What is the purpose of the signal wire in an ESC setup?
-The signal wire in an ESC setup carries the signal from the transmitter or flight controller that tells the ESC how much power to allow through to the motor, effectively controlling the motor's speed.
What are some of the traditional settings found on ESCs?
-Traditional settings on ESCs include brake, soft start, motor direction, low voltage alarm, response time, and advanced settings that affect how the ESC responds to throttle inputs.
What is the difference between SimonK and BLHeli firmware for ESCs?
-SimonK firmware is one of the first variants specifically written for multirotors, offering faster throttle response and being set up for a multicopter. BLHeli, a newer firmware, offers all the benefits of SimonK but also allows for more detailed settings adjustments through a PC connection using the BL suite of software.
What is the purpose of throttle calibration for ESCs?
-Throttle calibration ensures that the throttle range on the ESC matches the throttle range on the radio or flight controller, ensuring that the motor speed changes are accurate and consistent with the pilot's input.
What is a Battery Eliminator Circuit (BEC) and why is it important?
-A Battery Eliminator Circuit (BEC) is a part of the ESC that provides the +5 volts needed for the flight controller, servos, and other electronics in the craft. It is important because it powers these components without drawing power directly from the main battery.
What are the different types of BECs mentioned in the script?
-The script mentions linear BECs, which are simple but inefficient and can get warm; switched BECs, which are more efficient and support larger batteries; Optio BECs, which provide optical isolation but not +5 volts; and some high-power ESCs that have no BEC at all, requiring an external source for +5 volts.
What is the concept of 'one shot' in ESCs and how does it differ from the default signal?
-One shot is a new synchronous method for updating motor speed from the flight controller. Unlike the default 1 megahertz signal using pulse width modulation, one shot operates at 8 megahertz and updates the motor speed instantly as soon as the flight controller signals a change, making it faster and more responsive.
Outlines
🔋 Introduction to Electronic Speed Controllers (ESCs)
The video introduces Electronic Speed Controllers (ESCs), explaining their basic function in running motors and supplying power to flight controllers and other electronics in models. It addresses common questions and misconceptions, focusing on how ESCs work, the significance of the three wires, and their role in controlling motor speed and direction. The script also mentions the importance of ESC setup, including features like brake, throttle response, and timing.
🛠 Understanding ESCs and Motor Control
This paragraph delves into the technical aspects of ESCs, describing them as controllers for three-phase brushless motors. It explains the connection of motor wires to the ESC and the function of the additional signal wire that communicates power instructions. The explanation includes the process of how ESCs fire electromagnets to rotate the motor and use feedback from the rotor's position to control the motor's speed and direction. The paragraph also touches on the ability to reverse motor direction by swapping wires and the settings available in traditional ESCs.
📲 Firmware Options and Multirotor Compatibility
The script discusses various firmware options available for ESCs, including traditional, Simon K, and BL heli firmware. It highlights the benefits of Simon K and BL heli firmware, which are tailored for multirotor use, offering faster throttle response and configuration options. The paragraph explains the process of changing firmware using a bootloader and a USB cable, and it also introduces the concept of one-shot ESCs, which provide faster and more instantaneous motor speed updates through a synchronous connection.
🔧 Throttle Calibration and Battery Eliminator Circuits (BECs)
This section covers the importance of throttle calibration to ensure the ESC's throttle range matches the radio or flight controller's range. It also explains the different types of Battery Eliminator Circuits (BECs) found in ESCs: linear, switch, Optio, and none. The paragraph details the functionality and efficiency of each BEC type, the potential need for separate power sources, and the importance of proper BEC selection and installation for optimal model performance.
Mindmap
Keywords
💡Electronic Speed Controllers (ESCs)
💡Three-Phase Motor
💡Firmware
💡Throttle Calibration
💡Battery Eliminator Circuit (BEC)
💡Signal Wire
💡Brake
💡Soft Start
💡One-Shot
💡Multirotor
💡Optio
Highlights
Electronic Speed Controllers (ESCs) are devices that control motor speed in models and also supply +5 volts for other electronics.
ESCs have three wires due to the three-phase nature of brushless motors, which connect to the ESC to control motor direction and speed.
ESCs are equipped with a signal wire that communicates the required power level to the motor based on the ESC's internal computer code.
Traditional ESC settings include brake, soft start, motor direction, low voltage alarm, response time, and advanced settings for fine-tuning motor performance.
Firmware versions like Simon K and BL Heli are designed for multirotors, offering faster throttle response and configuration options.
Simon K firmware is known for its instant speed changes suitable for multirotors, while BL Heli provides additional configurability through PC software.
ESCs with a bootloader allow for easy firmware changes, making it simpler to switch between different versions like Simon K and BL Heli.
One-shot ESCs use an 8 megahertz signal for faster and more instant motor speed updates from the flight controller.
Throttle calibration is crucial for matching the ESC's throttle range with the radio or flight controller, ensuring consistent motor response.
Battery Eliminator Circuits (BECs) within ESCs provide the +5 volts needed for flight controllers and servos, with options like linear, switched, and Optio types.
Linear BECs are simple but inefficient, generating heat by dropping excess voltage, and are limited to lower current capacities.
Switched BECs are more efficient, converting voltage into pulses and smoothing it for use, and can support higher battery capacities.
Optio BECs offer optical isolation between power and signaling systems but do not provide +5 volts, requiring a separate BEC for power.
Some high-power ESCs do not include any BEC, requiring modelers to provide their own +5 volts for model electronics.
Understanding ESCs, their firmware, and BECs is essential for optimizing model performance and ensuring safe operation.
The video provides a comprehensive guide to ESCs, catering to both beginners and experienced hobbyists looking to enhance their model's capabilities.
Transcripts
in this video we're going to talk about
electronic speed controllers or II SCS
this is a subject that I've been asked
to do a video about from a couple of
subscribers so this is a subscriber
request so if you have asked for this
this is for you
ESC is and one of those topics that can
appear very complicated but they
actually do a little basic job in the
models that we have the two basic jobs
that they're doing is running a motor
but also in a lot of cases supplying the
+5 volts that the flight controllers
servos and other electronics in the
craft need to operate in this video
we're going to talk about a couple of
things and cover the main questions that
I'm getting asked about and why we're
doing the video
first of all we're going to talk about
how they actually work why there are
three wires come out of them because
normally you'd expect a black wire and a
red wire we'll talk about how they sense
how they control everything we'll talk
about the standard bits and pieces that
they have for set up things like brake
throttle response and timing that you
may hear about as well then we'll talk
about the firmware version there's a lot
of discussion about firmware and and
recently with the introduction of
multirotors we have lots of additional
choices so there are specialized speed
controllers now to run our motors that
are built and programmed just to work
with multirotors really well and you'll
hear about things like simon k or BL
heli firmware and we'll talk about what
that is and why it's different then
we'll do a little bit on throk and
calibration about why that's important
and what it actually does on the speed
controller and then finally we'll cover
a bit about becs as part the esc s so
the electronic speed controller is the
bit that runs the motor the B EC or the
battery eliminator circuit is the part
of the speed controller that provides
that 5 volts that we talked about but
there are lots of different options and
some speed controllers don't have that
in it at all so we'll cover this at a
reasonably high level but hopefully for
those of you that are little confused it
will give you enough context to go and
do your own research and read manuals
and understand what it's actually
telling you
so the first thing we'll talk about then
is how they actually work so a brushless
motor is actually a three-phase motor so
each of the wires actually connect to
one of the three wires on the electronic
speed controller so if we put a diagram
up here here we have our little three
wires on the right hand side these are
our motor connections and we can connect
them to any one of the three wires
coming out of the motor and we have to
make sure that all three are connected
and we'll explain why in a second on the
other side of the speed controller then
we have our classic black and red wires
those would normally connect to the
flight battery or to a Power
Distribution board if it's a multicopter
and then we have another cable that
comes out the side that's actually
supplying the +5 volts to the rest of
the craft but also has a signal wire on
it and the level on that signal wire is
telling the ESC how much power to allow
through to the motor so let's talk about
that three-phase thing and three wires
because that's a little confusing so
here's a diagram of our motor so the
middle is going to turn around and we
can see that each of these wires are
connecting to each side of an
electromagnet so those little gray bits
in the walls at the nine o'clock 2
o'clock and 6 o'clock position are
actually magnets so if we then apply
power to the red wire and the yellow
wire then it actually pushes electricity
through the electromagnet at the two
o'clock position and that then becomes
energized and pulls the rotor the
rotating bit of the motor towards it
then the black wire and the yellow wire
are powered up next and that then powers
up the electromagnet at the bottom of
the motor so that pulled the rotor down
to that position then the black wire and
the red wire are fired next and that
then pulls the rotor round to that
position and so on and what happens is
the speed controller is actually firing
these pairs of wires one after the other
faster and faster faster and faster and
that
pulls the rotor round and that's what
the speed control is doing not only is
the speed controller doing that it's
actually also listening to the feedback
that it gets because as the permanent
magnets that a part of the rotor are
pulled around and past the
electromagnets they also send back a
little money pulse back to the speed
controller which the speed controller
then uses to sense where the rotor is so
it knows where to fire the next
electromagnet so there's a lot of really
clever stuff going on inside the
computer code running on the speed
controller and what it's doing is
sensing the rotor and firing each of
those electromagnets in turn and pulling
it round in reality the inside of a
motor if you've ever seen your side one
it's far more complicated with that with
a lot more poles or being aligned at
different amounts so the inside of the
motor isn't simple but hopefully that
explains how it's actually working
that's why you need the three wires
that's also why if you swap any two of
those three wires around it actually
reverses the direction of the motor now
as we'll look at in a second some of the
more traditional speed controllers allow
you to set the forward or reverse
direction so you can tell it which of
the phases you want swap round in
software but if you're playing with
something like a Simon K or a BL heli or
even a traditional firmware DSC and the
motors going the wrong way the fastest
and easiest way to do it you just swap
any two of those three wires and you'll
reverse the rotation of the motor now
you'll see some words bandied around
when we're talking about traditional es
CS and traditional settings include
things like brake
so when es CS were originally brought to
market multirotors were a twinkle in the
inventors eyes so we were using them on
helicopters and planes also things like
gliders and sometimes when you cut the
throttle you wanted the propeller to
stop rotating really quickly you
wouldn't want that on something like a
helicopter because you want the blades
to continue
but on something like a glider where
maybe the propellers fold in flat
against the body for aerodynamics then
absolutely as soon as you cut the
throttle you'd want the engine to stop
dead and those propellers to fold in so
a brake used to be something that you
had to disable for things like
multirotors then you had something
called soft start soft start is the
ability to spin up the motor slowly so
if you are a little bit aggressive on
the throttle rather than the speed
controller just pile all the energy into
the motor and strip the cogs and gears
that you had in your model it would
slowly spin up the motor and once it was
up to speed then it would have a much
faster throttle response that was very
useful in things like remote-control
helicopters and still is because that
way you can put the throttle to the
level just below where you're going to
take off and the speed controller does
the rest for you and my earliest
helicopters they didn't have things like
soft start and you're a little bit
aggressive on the throttle you'd strip
the cogs things like motor direction in
the software you could actually set up
things like reverse and forward as we've
talked about and that could either be
done within something like a programming
card or you can actually use it through
actual throttle position and sticks on
the transmitter to go into a programming
mode there were things like a low
voltage alarm where if the voltage that
it saw dropped below a certain level it
actually started to reduce power to the
motor again very handy if you're in
something like a plane less handy if
you're in something like a helicopter
and something you absolutely don't want
if you have in a multi rotor then we've
got things like response time so that
was how quickly it would change the
motor speed so if you said one second
the motor needed to be at 60% throttle
and the next instant it was 80% throttle
then how quickly does it take the motor
from 60 to 80 percent because what
you're dealing with here is a physical
system and it takes a certain amount of
time to increase the speed of all of
that mass of the motor and the attached
propeller and then finally had some
called advanced and that is how far
forward in advance of the rotor coming
round you'd actually
the next set of electromagnets and that
depended on how fast the motor was
turning on how much power you wanted and
your individual setup getting advanced
wrong would sometimes cause horrible
noises and occasionally caused excess
heat in the motor so that's the kind of
stuff that you'll occasionally read in
the traditional settings so if we talk
about the firmware option there were
three that you can commonly come across
now when you're looking at speed
controllers and each of these are pretty
interchangeable but you have to program
and change them so a lot of speed
controllers these days you can actually
program them and put different firmwares
on them tends to be that you tend to be
able to go from traditional to Simon K
and then Simon K to BL heli and BL heli
- Simon K but it's tricky to get back to
the traditional code a lot of the
vendors don't tend to post that I'm not
going to talk about exactly how you do
that here I'm going to link in the
description to my video showing how I
program a speed controller with Simon K
you typically need a special cable and
some software but if you buy a Simon K
or BL heli speed controller that has
something on it called a boot loader
then by using a simple USB cable and a
program you can then change the both the
version of either Simon K or BL heli or
actually change between Simon K + BL
heli so it gets a lot easier so I'll
link to that video in the description if
you want to have a look at that but
we'll go through each of these firmware
options in turn and hopefully it will
start to make a little bit more sense so
traditional we've talked about already
so it's really one that came from plane
and helicopter use it's setup via the
remote control itself or via a
programming card
Simon K one of the first variants of
firmware to be specifically written for
multirotors and it sets all of those
settings that we've looked at it in the
traditional ESC up for a multicopter in
addition to that it also increases the
response time so when the flight
controller wants this change in speed to
be pretty instant the Simon K speed
controller will do it
best to get it there as fast as it
possibly can really really great for
multirotors and a lot of my models here
run on simon k firmware and that's
actually the version of the software
that's flashed on to my speed
controllers in the video that I've
talked about the third one then is BL
heli and this is a little bit newer but
it's starting to appear in lots of
different places and there's very
distinct camps some love Simon K some
love BL heli and I think they're both
really good
the advantage of BL heli over Simon K is
that not only does it give you all of
the benefits of Simon K in terms of the
faster throttle response being set up
for a multi rotor really well but it
also then allows you via the BL suite of
software to go and connect it to your PC
via a USB cable and to change the
settings and set it up how you want it
to be so where Simon K your only option
really is to flash the software and you
have versions and different versions
have slightly different characteristics
with BL heli if you want to change
something on it you can absolutely
connect to it just like a traditional
firmware you can change it to be the way
you need there are instances I've read
where BL heli is a little bit better
with some of the larger low speed motors
so if you're using really big props and
really low kV motors then BL heli can
sometimes be a better option for you but
as we talked about if you have a Simon K
or a BL heli speed controller that
already has a boot loader on it then you
can get hold of one of the USB cables
then you can actually start changing and
swapping things around my personal
advice would be I would actually get one
or the other both in the majority of
instances will work really well by ESC s
that already come pre flashed with
either Simon K or BL heli if you're
going to use it for a multi rotor make
sure it has a bootloader installed and
when you order your speed controllers
I'd always recommend ordering a separate
one anyway for spares and order whatever
associated USB cable comes with it for
programming and then if
you find this a problem you can change
your mind last thing we'll talk about
then is the one shot you'll have heard
about this and read it in places about
one shot es si s now one shot is a
relatively new thing so if you're
watching this in 2017 and it probably
doesn't feel very new but right now it
kind of is one shot is a new synchronous
way that you can get the updates from
the flight controller for how fast the
motor needs to run by default it's a 1
megahertz signal coming from the flight
controller using pulse width modulation
and actually changing the speed of the
motor the way one shot works is
increases that update speed to 8
megahertz and uses a synchronous
connection so that as soon as the flight
controller needs a change in the speed
of the motor then that is sent once
which is why I think it's called one
shot up to the speed controller to
change that speed so it's an awful lot
faster and it's a lot more instant you
have to of course not only have one shot
es es you also need to have flight
controllers that also understand one
shot as well so let's quickly talk about
throttle calibration throttle
calibration is the process that you use
to make sure that the throttle range on
the speed controller it matches the
throttle range on either your radio or
your flight controller when you come
into the hobby it's a bit confusing to
think that there's no standards for what
the throttle range is but in reality
everyone has their own slightly
different version and different radios
output different throttle ranges
different flight controllers can be set
up to have different possible ranges so
you have to tune and setup the ESC so it
understands where high and where low
throttle is you can also find the esc s
from the same manufacturer might have
slightly different settings so if you
have a quadcopter you might find that
when you arm the quadcopter and increase
the throttle three of the motors will
start and one of them will be lazy until
you get to about 10% trottle and that'll
start running that's because you haven't
done esc calibration so what esc
calibration does is teaches the esc
where the high-low point is and you
could always do that as part of your
setup
some of the firmwares like the simon k
firmwares are predefined high and low
points and that's one of the values of
having a multicopter specific firmware
but I would always recommend it's
worthwhile going through it anyway if
you want to know more about ESC
calibration I'll put a link in the
description to one of my videos where I
actually show the process which is a
guaranteed way to make sure it works
every time so the last thing we'll talk
about then are battery eliminator
circuits becs so a lot of esc s will
come with a battery eliminator circuit
on them and the battery eliminator
circuit or becs job is to provide the +5
volts that run your flight controller
the servos and everything else on the
model so let's go through each of these
in turn
and the first one we'll talk about is
linear linear is a really simple circuit
it reduces the voltage by getting rid of
the excess voltage as heat so it tends
to get quite warm because of this
inefficiency only really supports what
kind of 4s lipo batteries and they tend
to be lower current capacity as well the
nice thing with linear becs is that you
can plug multiple ones into a flight
controller side-by-side and you don't
need to worry about it switched becs are
a lot cleverer they are a little circuit
that breaks up the voltage into little
pulses and then smooth that into the +5
volts that you need much much more
efficient isn't wasting any power as
heat also tends to support much larger
batteries like five six seven eight nine
s the thing you have to be careful over
the switch to be ec is it should only
really install one at once because it
has some advanced electronics that's
actually sensing the output voltage and
trying to accommodate that output
voltage and maybe have a little bit more
power a little bit less as it sees the
+5 volts go up or down if you have two
or three connected together they can
fight each other so with these if you're
going to have for electronic speed
controllers in the quadcopter and they
have switched becs then you need to pop
off three of the four red wires on the
way in and just use one B EC from one of
the ESC s to power everything if you've
got swear
Optio Optio is an interesting one it
doesn't actually provide the +5 volts to
the flight controllers and everything
else it provides optical isolation
between the power system and the
signaling system which is a good idea
thing you have to be careful of here if
you're getting up to your speed
controllers you need another battery
eliminator circuit a separate little one
that you buy and you power the model
from that the thing you have to be
careful with Optio is that a lot of them
will only power on and run if they see
that +5 volts on the output rail and the
last one is some of the really large
high-power speed controllers for the big
motors don't have any done at all
they're not interested in providing the
+5 volts that you need for your model so
you have to completely sort that out
yourself so it's kind of like Optio in
that respect so very quickly if it's
linear you plug everything in dead easy
dead simple can get a bit warm so just
don't use them on more than 4s switched
more efficient don't only plug one red
wire in at once Optio don't provide +5
volts at all so use something else to
provide the power and none well you know
what you're going to have to sort that
out yourself so we've been going for a
little while now we're coming up on the
20 minute mark hopefully that explains
some of the concepts and how ESC s
worked we've talked about how the
three-phase motor works the power how
they send some of the standard settings
on traditional firmware then we've
looked at firmware itself how we kind of
program them we've talked about three of
the most common ones that you'll come
across we've talked about B each season
esc s and we've also talked about
throttle programming thank you for
taking the time to watch that video
there are lots of other videos on the
channel and they're carefully ordered
into playlists so you may find that
there are other videos on this same
subject that you can go and watch so I
would recommend going into the playlist
area of painless 360 YouTube channel and
looking around and seeing what there is
you never know what you might find
thanks for watching please like
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