PCB stator design for DC motor (for single phase?)

Thread Starter

friendy

Joined Mar 23, 2023
6
Hello,

I'm wondering if it's possible to design a PCB stator as part of a single phase DC motor. I've seen a lot of 3 phase PCB designs but wonder if anyone has knowledge of any single phase designs even existing. I'm both not an EE and new to motor terminology/designs so finding answers has proven difficult. thx!
 

panic mode

Joined Oct 10, 2011
2,703
difficult terminology?
DC is DC... no phases
when you start talking about phases (one or three phases) it means AC
also you need numbers. motor power, speed, voltage. then lookup motor of same specs and see if you could convert it to PCB design.
 

MaxHeadRoom

Joined Jul 18, 2013
28,576
Maybe the OP is referring to the three windings or 'Phases' in a BLDC motor.?
This motor can be used in BLDC (DC) or 3ph modes.
Just the commutation is different.
The terminology starts to get a little blurry! :oops:
 
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Thread Starter

friendy

Joined Mar 23, 2023
6
Maybe the OP is referring to the three windings or 'Phases' in a BLDC motor.?
This motor can be used in BLDC or 3ph modes.
Just the commutation is different.
The terminology starts to get a little blurry! :oops:
I'm looking to make a pretty small motor (think common toy size) that runs on 9v that only needs one PWM signal from a 555 timer to run as opposed to 3 PWM signals. Because I'm a beginner with blurry terminology all around I'm not certain what to ask or how to define size. I'll look up what commutation is now :) Thanks for your help!
 

Thread Starter

friendy

Joined Mar 23, 2023
6
difficult terminology?
DC is DC... no phases
when you start talking about phases (one or three phases) it means AC
also you need numbers. motor power, speed, voltage. then lookup motor of same specs and see if you could convert it to PCB design.
hey thanks for your help.
ok good to know that means AC.
9v, 3000rpm is all the information i know given my knowledge.

So i've only found AC (three phase) PCB designs. Do you know if a DC motor that only uses a single PWM signal (for example from a single 555 timer) could use a PCB Stator design (coils made by traces)?
 
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panic mode

Joined Oct 10, 2011
2,703
What do you mean by difficult terminology?
as an engineer i expect to see numbers. i have no idea what others may call "pretty small motor" or "common toy size". some toy with 15m tall trebuchets that throw cars across the field. others may toy with silly MEMS contraptions. i don't know how common either of them are. but my things i consider toys come in all sizes.

if i am to guess, you are probably looking at something like this:
 

Audioguru again

Joined Oct 21, 2019
6,647
The small cheap DC motors in toy helicopters, small drones and small toy airplanes soon burn out their brushes.
The motors were first used in a vibrating pager, then to open and close a CD tray. The motors are called "coreless".
 

KeithWalker

Joined Jul 10, 2017
3,050
Hello,

I'm wondering if it's possible to design a PCB stator as part of a single phase DC motor. I've seen a lot of 3 phase PCB designs but wonder if anyone has knowledge of any single phase designs even existing. I'm both not an EE and new to motor terminology/designs so finding answers has proven difficult. thx!
The stator in a DC motor is usually a magnetic circuit consisting of one or more magnets and shaped magnetic poles. An electro magnetic stator would require lots of turns and would need enough current to produce a useable magnetic field. That would not be a suitable subject for design as a PCB. In a motor, the torque depends on the product of the current and number of turns on the armature. For a 9V toy motor quite a few turns will be require so that too would not be very suitable for disign using PCB. The only part of the motor that would be suitable to be designed using PCB is the commutator.
 

Thread Starter

friendy

Joined Mar 23, 2023
6
Any reason you cannot use a small already available DC motor as opposed to making one?
It's mainly a form factor thing. I need to make it very thin and am using PCB in my design anyway.
Yea by small I mean a thin pancake shape approximately 40-50mm in diameter. The spinning magnet disc mounted to the PCB would be about 4mm tall.
 

Thread Starter

friendy

Joined Mar 23, 2023
6
as an engineer i expect to see numbers. i have no idea what others may call "pretty small motor" or "common toy size". some toy with 15m tall trebuchets that throw cars across the field. others may toy with silly MEMS contraptions. i don't know how common either of them are. but my things i consider toys come in all sizes.

if i am to guess, you are probably looking at something like this:
Yea exactly, something like that but if I'm not mistaken that example is using 3 PWM signals (I can only used one PWM signal in my design). Good point about the toy sizes. I'm looking for 40mm diameter pancake size at about 10mm overall thickness once the magnet disc is attached like in the video example you provided.
 

Thread Starter

friendy

Joined Mar 23, 2023
6
The small cheap DC motors in toy helicopters, small drones and small toy airplanes soon burn out their brushes.
The motors were first used in a vibrating pager, then to open and close a CD tray. The motors are called "coreless".
[/Q
The stator in a DC motor is usually a magnetic circuit consisting of one or more magnets and shaped magnetic poles. An electro magnetic stator would require lots of turns and would need enough current to produce a useable magnetic field. That would not be a suitable subject for design as a PCB. In a motor, the torque depends on the product of the current and number of turns on the armature. For a 9V toy motor quite a few turns will be require so that too would not be very suitable for disign using PCB. The only part of the motor that would be suitable to be designed using PCB is the commutator.
Thank you, I'm not sure if this changes what you are saying here but Panic posted a video above of the motor design example. And i'm looking for an answer if running this type of design with a single PWM circuit is possible.
 

MaxHeadRoom

Joined Jul 18, 2013
28,576
In a BLDC motor, although only two conductors out of the three are energized at any one time, it still requires a three signal PWM, the only way with one PWM power signal is a DC brushed motor.
 

KeithWalker

Joined Jul 10, 2017
3,050
Thank you, I'm not sure if this changes what you are saying here but Panic posted a video above of the motor design example. And i'm looking for an answer if running this type of design with a single PWM circuit is possible.
No, it is not practical. It could be done but it would not start without help.
 

panic mode

Joined Oct 10, 2011
2,703
all electric motors work by producing magnetic field that is somehow changing. either with the help of commutator (like in DC motor) or with electronics (like BLDC) or using rotary magnetic field produced by AC. the rotary magnetic field in 3phase circuit is quite obvious but some types AC motors can be powered by single phase too. those use commutator (like DC motors) or need rotary magnetic field that is produced by another "phase". this could be obtained by additional components like start capacitor or shaded magnetic pole. when working with PCBs the most reasonable solution is to generate polyphase in electronic. for example use 555 as an oscillator to drive counter like 4017... just like in chasing light circuits.
 
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