RC Basics - Understanding Electronic Speed Controllers (ESC)

Summary

In 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

00:00

🔋 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.

05:02

🛠 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.

10:04

📲 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.

15:05

🔧 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.

Keywords

💡Electronic Speed Controllers (ESCs)

ESCs are devices that control the speed of electric motors in models, such as drones and RC planes. They are central to the video's theme as they perform the basic job of running the motor and, in many cases, supplying power to other electronics. The script explains how ESCs work with three wires and how they have evolved with firmware versions like Simon K and BL Helicopter, which are specialized for multirotors.

💡Three-Phase Motor

A three-phase motor is a type of electric motor that operates on three alternating current (AC) electricity supplies. In the script, it's described as the motor type used in conjunction with ESCs, where each of the three wires connects to the motor, allowing the ESC to control the motor's speed and direction.

💡Firmware

Firmware refers to the software that provides the instructions for an electronic device. In the context of ESCs, different firmware versions like traditional, Simon K, and BL Helicopter are mentioned, each offering specific features and optimizations for different types of models, particularly multirotors.

💡Throttle Calibration

Throttle calibration is the process of ensuring that the ESC understands the full range of throttle inputs from the control system. It's essential for matching the ESC's throttle response with the pilot's input, as the script explains the importance of this process in setting up ESCs for optimal performance.

💡Battery Eliminator Circuit (BEC)

A BEC is a part of the ESC that provides a stable 5-volt power supply for the flight controller and other electronics. The script discusses different types of BECs, such as linear, switched, and Optio, and their roles in supplying power and the considerations needed when using them.

💡Signal Wire

The signal wire is a component of the ESC that carries the control signal from the flight controller to the ESC, indicating how much power to deliver to the motor. The script explains that the signal wire's level tells the ESC how to regulate the motor's speed.

💡Brake

In the context of ESCs, a brake is a feature that allows for rapid deceleration of the motor when the throttle is reduced. The script mentions it as a setting that was important for certain models like gliders but not for multirotors.

💡Soft Start

Soft start is a feature that allows the motor to spin up slowly to prevent damage to the model. The script explains how this feature is useful in models like helicopters where a sudden burst of power could be detrimental.

💡One-Shot

One-Shot refers to a type of ESC signal processing that allows for faster and more precise motor speed updates. The script describes it as a new synchronous method that increases the update speed to 8 megahertz for immediate motor response.

💡Multirotor

A multirotor is a type of aircraft with multiple propellers, commonly used in drones. The script discusses how ESCs and their firmware have been adapted to work specifically well with multirotors, with features like faster throttle response.

💡Optio

Optio is a type of BEC that provides optical isolation between the power and signaling systems, rather than supplying 5 volts. The script explains that while it offers benefits in terms of safety, it requires an additional BEC for providing power to the flight controller and other electronics.

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

subscribe and happy flying