Any recommended lightweight high current ~15v regulator for quadcopter?

Anyone know of a lightweight 15 volt regulator that I can put on a drone? I need to convert 22.2 volts down to 14.8 in order to power some motors. Each motor should use around 40amps of current max. I imagine if I can find a regulator that can flow at least 10amps then I can connect 4 together for each motor?

The lighter the better for efficency, thanks!

I need to convert 22.2 volts down to 14.8 in order to power some motors.

A common misconception. Run the motors direct from 22.2V, and use PWM to reduce the drive to the motors,
problem solved. (Well, you need a 40A motor driver, so not quite)

Trying to connect voltage regulators in parallel is likely to blow everything up.

MarkT:
A common misconception. Run the motors direct from 22.2V, and use PWM to reduce the drive to the motors,
problem solved. (Well, you need a 40A motor driver, so not quite)

Trying to connect voltage regulators in parallel is likely to blow everything up.

Thanks for your reply!
Forgive me if I'm missing something but wouldn't using pwm still maintain 22.2 volts to the motors. The motors are rated at 15 volts and cannot take 22.2v at all.

Would the regulators in parallel still likely blow up if diodes were placed after each one? What if they contained their own internal diodes. Sorry for the noob questions?

The motors are rated at 15 volts

on average.

Would the regulators in parallel still likely blow up if diodes were placed after each one?

Yes. Never use regulators in parallel.

05silgto:
Thanks for your reply!
Forgive me if I'm missing something but wouldn't using pwm still maintain 22.2 volts to the motors. The motors are rated at 15 volts and cannot take 22.2v at all.

I really don't believe that - its a motor, its a set of windings. Motors fail through over heating or over-speed, or
insulation breakdown. Insulation breakdown isn't going to happen at 22V, over speed can be prevented
by setting the PWM level correctly, and overheating risk is then no different from running directly from 15V

What are these motors?

Voltage regulators in parallel will end badly unless they are specifically designed to run in tandem and have
current sharing behaviour. Parallel regulators if you are lucky just don't share current and only one carries the
current, if you are unlucky the setup is unstable, oscillates at full swing and fries everything, seen it happen.

MarkT:
I really don't believe that - its a motor, its a set of windings. Motors fail through over heating or over-speed, or
insulation breakdown. Insulation breakdown isn't going to happen at 22V, over speed can be prevented
by setting the PWM level correctly, and overheating risk is then no different from running directly from 15V

What are these motors?

Voltage regulators in parallel will end badly unless they are specifically designed to run in tandem and have
current sharing behaviour. Parallel regulators if you are lucky just don't share current and only one carries the
current, if you are unlucky the setup is unstable, oscillates at full swing and fries everything, seen it happen.

They are emax eco 2306 2300kv(edit:2400kv not 2300.)
If that's the case I could probably set a limit on the flight controller(ardupilot) hopefully. First time making a drone so I'm a bit of a noob.
I might end up using a nano if I can't configure my engine setup for my specific setup anyway so I could just use that to control the esc speed I imagine.

If not I found this regulator
https://www.analog.com/en/products/lt8228.html#product-overview

Looks rather complicated to me though. Not sure on the weight. Should support 40a and can be used in parallel if needed for added redundancy.

I should also add that this will be a coaxial quadcopter so 8 engines total.(4 on top 4 directly below other motors.)
4 of the motors run off of the 22.2 volt power supply and are the main motors and the emax motors are the other 4 which are the backup motors. This is for added redundancy in case a motor fails the secondary engines will switch on and the main engines geared for max efficency.

From what I understand when the secondary engines are unpowered and spinning from the airflow from the main engines it will generate reverse current so some form of current check valve will be needed regardless.

From what I understand

It appears that your understanding is rather limited, and not up to the requirements of this project.

I suggest to start with something less ambitious, and gain relevant experience.

Perhaps you should back up a little.

The motor you referenced is a brushless motor, so you need a brushless driver. Do you have a brushless driver in mind?

JohnRob:
Perhaps you should back up a little.

The motor you referenced is a brushless motor, so you need a brushless driver. Do you have a brushless driver in mind?

In fpv/Rc we use electronic speed controllers(ESC). I have everything picked out already, 40A ESC's for each motor.

It looks like I should be able to supply 22.2 volts safely if I turn down the max throttle in order to keep the wattage the same.

I found a couple different possible codes in ardupilot that may solve this already.

"MOT_BAT_VOLT_MAX: Battery voltage compensation maximum voltage
Note: This parameter is for advanced users
Battery voltage compensation maximum voltage (voltage above this will have no additional scaling effect on thrust). Recommend 4.4 * cell count, 0 = Disabled

Units Range
volt 6 - 35

MOT_SPIN_MAX: Motor Spin maximum
Note: This parameter is for advanced users
Point at which the thrust saturates expressed as a number from 0 to 1 in the entire output range

Values
0.9:Low, 0.95:Default, 1.0:High"

Now I just need to figure out the best way to activate the secondary engines and if I can do so with ardupilot.

jremington:
It appears that your understanding is rather limited, and not up to the requirements of this project.

I suggest to start with something less ambitious, and gain relevant experience.

Yes, my understanding is quite limited. That is why I am on a forum asking questions in order to extend my understanding. Starting with something "less ambitious" might help with basic quadcopter functions/design, but it's not going to provide me with "relevant experience" associated with my rather unique questions.

I did further research and it appears newer ESC's are designed to withstand reverse current, the current should end up causing engine braking. I plan on looking into this further just to double check.

What ESCs are you using and why are using 22Vwhen all escs are designed for standard lipo voltages ? Why aren't you using the correct XSXP
battery configuration ?

05silgto:
They are emax eco 2306 2300kv(edit:2400kv not 2300.)

Those are 4S motors, they will overheat with a 6S pack. The kv = 1700 version of that motor is 6S.

You didn't make it at all clear you were talking about the main motors for the quadcopter, you said
"power some motors"
The main motors need to be carefully chosen with matching props and matching ESCs to handle the
lift force + safety margin needed for max craft weight. The mass-budget needs to be carefully worked out
so that the motors are powerful enough, but not too powerful (which would be heavier),
running at the right rpm for the props, and matched to the ESCs and LiPo pack.

The better subject line for this thread would be "please help with my quadcopter design". The regulator thing
was an an "xyproblem".

The basic approach to designing anything with electric motors is do the sums first, figure out what you
need, then buy the motors and matching power source/drivers. Buying motors without doing the sums
means you'll have the wrong motors 90% of the time.

raschemmel:
What ESCs are you using and why are using 22Vwhen all escs are designed for standard lipo voltages ? Why aren't you using the correct XSXP
battery configuration ?

I'm using a 6s lipo battery which equals 22.2 bolts. The ESC I currently have picked out is designed for 6s.
You take 3.7 volts times the cell count of the battery to arrive at the final voltage. 6 x 3.7= 22.2
My main motor are tarot 4008 380kv and can handle 6s, thats why I plan on using 6s.

MarkT:
Those are 4S motors, they will overheat with a 6S pack. The kv = 1700 version of that motor is 6S.

You didn’t make it at all clear you were talking about the main motors for the quadcopter, you said
“power some motors”
The main motors need to be carefully chosen with matching props and matching ESCs to handle the
lift force + safety margin needed for max craft weight. The mass-budget needs to be carefully worked out
so that the motors are powerful enough, but not too powerful (which would be heavier),
running at the right rpm for the props, and matched to the ESCs and LiPo pack.

The better subject line for this thread would be “please help with my quadcopter design”. The regulator thing
was an an “xyproblem”.

The basic approach to designing anything with electric motors is do the sums first, figure out what you
need, then buy the motors and matching power source/drivers. Buying motors without doing the sums
means you’ll have the wrong motors 90% of the time.

I’m way ahead of you buddy.
I used ecalc to do all the calculations. The extra weight from the other motors are factored into each calculation. If only I could factor drag from the other propellers too. The 2400kv version had a better thrust to weight watio on 4s than the 1700kv version did on 6s. This is why i’m using the 2400kv version.

Please let us know when you have found the right lightweight voltage regulator for your motors.

You can calculate all you want but it won't do any good if there are no dc to dc converters that can handle the current load. Did you Google "25V to 17V (4S are 16.8V charged, NOT 15V) dc to dcconverters" Do you have ANY idea how much a 700W dc to dc converter would weigh ? (multiply that time 4) The only way you could know that is by reading the datasheet which means you would slready know the part number which means you wouldn't be posting with the title " Does anybody know ....?"
The voltage drop required (input to output) is
what the converter needs to dissipate.
25.2-16.8 = 8.4V
Power(W) = VI (voltage x current)
= 8.4
40A
P = 336W

As an example , this one, in the 500W version weighs just over a pound. (multiply that times 4)
Of course this is not the correct output voltage but only presented as a weight example.
DC to DC converter (500W)
If it's a high efficiency switching converter then
this doesn't apply.
Either way a dc to dc converter that can output
16.8V @40A is going to be heavy.
Getting 4 of them on a quadcopter doesn't seem
realistic.

"You take 3.7 volts times the cell count of the battery to arrive at the final voltage. 6 x 3.7= 22.2 "
False.
You use the CHARGED voltage (4.2V/cell)
4*4.2V/cell=16.8V.
Your 6S pack is 8.4V higher than the 4S ESC
Input voltage.

25.2V-16.8V=8.4V
6*4.2V=25.2V (charged) NOT 22.2V.
The input voltages for ESCs is the EXACT voltage
applied to the input. 3.7V is an uncharged cell
so you're not even going to get off the ground
with a 6S cell measuring 22.2 V because that would mean it is not charged. That's RC-101.
I would expect someone building a quadcopter
to already know that.
Bottom line is the answer to your post title
question is:" NO".

"
Please let us know when you have found the right lightweight voltage regulator for your motors"

Don't hold your breath.

raschemmel:
You can calculate all you want but it won't do any good if there are no dc to dc converters that can handle the current load. Did you Google "25V to 17V (4S are 16.8V charged, NOT 15V) dc to dcconverters" Do you have ANY idea how much a 700W dc to dc converter would weigh ? (multiply that time 4) The only way you could know that is by reading the datasheet which means you would slready know the part number which means you wouldn't be posting with the title " Does anybody know ....?"
The voltage drop required (input to output) is
what the converter needs to dissipate.
25.2-16.8 = 8.4V
Power(W) = VI (voltage x current)
= 8.4
40A
P = 336W

As an example , this one, in the 500W version weighs just over a pound. (multiply that times 4)
Of course this is not the correct output voltage but only presented as a weight example.
DC to DC converter (500W)
If it's a high efficiency switching converter then
this doesn't apply.
Either way a dc to dc converter that can output
16.8V @40A is going to be heavy.
Getting 4 of them on a quadcopter doesn't seem
realistic.

"You take 3.7 volts times the cell count of the battery to arrive at the final voltage. 6 x 3.7= 22.2 "
False.
You use the CHARGED voltage (4.2V/cell)
4*4.2V/cell=16.8V.
Your 6S pack is 8.4V higher than the 4S ESC
Input voltage.

25.2V-16.8V=8.4V
6*4.2V=25.2V (charged) NOT 22.2V.
The input voltages for ESCs is the EXACT voltage
applied to the input. 3.7V is an uncharged cell
so you're not even going to get off the ground
with a 6S cell measuring 22.2 V because that would mean it is not charged. That's RC-101.
I would expect someone building a quadcopter
to already know that.
Bottom line is the answer to your post title
question is:" NO".

"
Please let us know when you have found the right lightweight voltage regulator for your motors"

Don't hold your breath.

I appreciate your input but at this point I was leaning more towards hooking up the 6s batteries directly to those motors and limiting the max throttle for those specific motors in order to achieve the same wattage. Thanks to the help I received from the other posters it looks pretty doable. Those motors are not very expensive in case things don't go as planned. Honestly, I'm more focused on the coding at the moment, and how I'm going to be able to get the secondary motors set up in ardupilot as backup engines. I'm going to use way-points with this build a lot so I wanted the secondary motors to only activate in the case of a engine failure, automatically somehow. It would be easy to do with a nano and a small npn transistor between the signal wires of the motor and flight controller but I'm sure there's some other way to achieve the same result somewhere in the ardupilot code.

In short , you abandoned the regulator idea as not doable and chose the throttle limit approach.
You could have saved time by simply asking if it is possible to us a 6S battery pack with 4S motors.
Is that not the case?

raschemmel:
In short , you abandoned the regulator idea as not doable and chose the throttle limit approach.
You could have saved time by simply asking if it is possible to us a 6S battery pack with 4S motors.
Is that not the case?

I had no idea when I started this thread that it was possible to do so. Thanks to the posters here I learned it was possible and was able to find a solution to my problem. It's easier to limit the throttle of the motors than to add extra components and weight. I wouldn't say I "abandoned the regulator idea as not doable", I just found a better and more logical approach to solve my problem. At this point, even if the regulator was doable, and only added a gram of weight, I would still not use one. With that being said, I'm sure the regulator idea is very impractical

I also would like to take the time to thank everyone who took the time to offer me advice and input on this subject. Not only did you help me solve my issue but I ended up learning a lot in the process.