Washing Machine Motor

Wire Colors

I used

Phase 1 (red)	Ground	8 Ω
Phase 2 (yellow)	Ground	8 Ω
Phase 3 (blue)	Ground	8 Ω

Phase 1 (red)	Phase 2 (yellow)	17 Ω
Phase 1 (red)	Phase 3 (blue)	17 Ω
Phase 2 (yellow)	Phase 3 (blue)	17 Ω

It seems like I screwed up the decimal point and it should be 10.5 mH, not 105 mH

Phase 1 (red)	Ground	105 mH
Phase 2 (yellow)	Ground	105 mH
Phase 3 (blue)	Ground	105 mH

Phase 1 (red)	Phase 2 (yellow)	39 mH
Phase 1 (red)	Phase 3 (blue)	39 mH
Phase 2 (yellow)	Phase 3 (blue)	39 mH

Phase 1 (red)	Ground	189 pF
Phase 2 (yellow)	Ground	192 pF
Phase 3 (blue)	Ground	198 pF

Phase 1 (red)	Phase 2 (yellow)	118 pF
Phase 1 (red)	Phase 3 (blue)	120 pF
Phase 2 (yellow)	Phase 3 (blue)	120 pF

When a phase wire is connected to the "+" side of the battery, the outside part of the coil pulls toward the South.

Phase 1 (red) Phase 2 (yellow) Phase 3 (blue)	Ground	Direction
Connected to
-	+	Outside of coil pulls north
+	-	Outside of coil pulls south

Phase 1 (red)	Phase 3 (blue)
Connected to
-	+	Phase 1 (red) pulls north Phase 3 (blue) pulls south
+	-	Phase 1 (red) pulls south Phase 3 (blue) pulls north
Phase 1 (red)	Phase 2 (yellow)
Connected to
-	+	Phase 1 (red) pulls north Phase 2 (yellow) pulls south
+	-	Phase 1 (red) pulls south Phase 2 (yellow) pulls north
Phase 2 (yellow)	Phase 3 (blue)
Connected to
-	+	Phase 2 (yellow) pulls north Phase 3 (blue) pulls south
+	-	Phase 2 (yellow) pulls south Phase 3 (blue) pulls north

The wheel or armature that spins has 36 magnets in it.

The magnetic fields alternate.

One magnet will have it's north field pointing up and the next magnet will have it's south field pointing up.

I used a magnet to verify that instead of the compass.

It was the magnet with one flat side and the other side was curved.

The flat side of the magnet stuck to every other magnet.

I can't tell if the wheel has a starting position or number one position.

Oddly there are 36 magnets, but only 27 coils.

There are 1.33 magnets for every coil.

There are 0.75 coils for every magnet.

The stator or non-moving part has 27 coils.

Each phase, i.e. phases 1 thru 3 has 9 coils.

All 9 coils for each phase are connected electrically.

The coils for the 3 phases are connected in a "Y" configuration. That is a "Y" configuration verses a "delta" configuration.

The center of the "Y" configuration is the ground wire. Phase 1 is the first arm of the "Y", phase 2 is the second arm of the "Y", and phase 3 is the bottom arm of the "Y".

You can run current thru:

In each of those cases you are running current thru 18 coils.

When you run current thru 2 different phases, the magnetic fields in each of the phases flip flops.

I.e. if you are running current thru phase 1 and phase 2, the outside of all the coils in phase 1 will have a north pole, and the outside of all of the coils in phase 2 will have a south pole or vice versa.

Oddly there are 36 magnets, but only 27 coils.

There are 1.33 magnets for every coil.

There are 0.75 coils for every magnet.

There are 1.33 magnets for every coil.

There are 0.75 coils for every magnet.

We have 36 magnets on the rotating armature. We have 18 magnets on the rotating armature with the north pole up, and 18 magnets on the rotating armature with the south pole up.

We have 3 hall effect sensors mounted on the non-moving stator.

How many times are the hall effect sensors fired during one revolution of the motor?

During one revolution of the armature, the Hall Effect sensors each fire 18 times for each phase.

That is a total of 54 firings for all three hall effect sensors combined.

Remember while we have 36 magnets, 18 or half of them have their north poles facing up. The other 18 of them have south poles facing up.

The Hall Effect sensors are the type that only are triggered by one pole. I.e., they are either triggered by the north pole of the magnet, or the south pole of the magnet, but not both poles.

Since the magnets are installed with half of their north poles facing up and the other half with their south poles facing down, only half of the 18 magnets will fire the Hall Effect sensors. The other 18 magnets have their pole reversed and don't trigger the Hall Effect sensor.

The signal names are from the printed circuit board on the machine.

The wire colors are from the connector that plugs into the printed circuit board.

I used the 3 colors of the wires that control the hall effect sensors for each phase to guess the colors of the power wires that drive each phase.

I suspect these are the colors and phases.

1) the phases are just guesses, based on the color of the wires in the hall effect table.

2) I don't have the original connector from the circuit board to the 3 sets if coils for phase 1, 2 and 3, so I made these guesses based on the color of the wires from the Hall effect sensors.

Location of hall effect sensors on the plastic hall effect assembly

Voltages hooked to hall effect sensors and wires

Firing order of hall effect sensors.

As I turn the armature in a clockwise direction the hall effect sensors fire in this order. If I turn it in a counterclockwise direction the order is reversed.

Why is the YELLOW LED for phase 2 much dimmer than the RED LED for phase 1 and the GREEN LED for phase 3?

I suspect that all 3 LEDs are pretty much the same intensity and it's just a matter of perception and our eyes precedence that the YELLOW LED is dimmer.

I replaced the YELLOW LED with a RED LED and the RED LED looked much brighter.

I measured the voltage across the 3 LEDs and they were all pretty close.

The voltage across the YELLOW and RED LEDs were almost identical. The difference was only about .017 volts or about 1/50 of a volt.

The difference between the YELLOW and GREEN LEDs was slightly higher, 0.589 volts or about .6 volts. Not sure why.

Voltage across LEDs

Voltage difference between LEDs

For single phase motors it sounds like they have a starting cap, which is used to determine the direction the motor rotates

Good question. Does it matter the direction the washing machine motors turns???

I suspect it really doesn't matter.

For a spin cycle all you want to do is spin it really fast to squeeze the water out of the cloths. You don't care which direction it spins.

For normal washing, I suspect you just want to make the motor flip flop. Turn one way for a second, then turn the other way for a second.

And in that case you don't care about the order the motor moves in. Just as long as it flips direction every second or so.

Of course an AC motor that drives a saw or a drill, the direction would be very important.

You gotta spin it in the right direction to make the teeth cut.

Source

SNIP

Definition of Start winding: in an A/C (alternating current) electric motor electrical current flowing through the start winding is used just to get the motor spinning from a stopped condition.

The start winding is disconnected, usually by a centrifugal switch, when the motor is up to speed.

Definition of Run winding: in an A/C electric motor the run winding is what keeps the motor spinning once it has started.

Current flowing through this winding produces a rotating magnetic field in the stator that keeps the motor shaft turning after the start winding has turned off.

Electric motor start switch: a centrifugal switch connects the A/C electrical power to the motor to the start winding on the stator until the motor has reached a speed typically of 75-80% of its full run speed (typically that's1725 rpm or 3450 rpm on newer high-speed oil burners).

SNIP

In a fixed-direction electric motor such as on an HVAC blower fan or an A/C or heat pump compressor, each time the motor starts its start capacitor and start winding give the motor a "kick" in the right direction.

[OK, where are these magic "start caps" and "start windings"]

Source

SNIP

Reversing the direction of a 3 phase motor can be done by swapping the connection of any two phases. [All the other articles agree with this. So it sounds like the direction of a 3 phase motor is determined by the firing order of the phases]

SNIP

Reversing the direction of a 3 phase motor can be done by swapping the connection of any two phases. [or in my case by the software]

The same article also explains how the motor is forced to start in one direction

Source

SNIP

A single phase motor has 2 windings electrically located at 90 degrees apart. One is designed to magnetize earlier than the other by using a capacitor or by using thinner wire for the windings depending upon the type of motor it is..

The winding with a capacitor in series will magnetize slightly earlier than the winding without the capacitor. So what happens is there appears to be a moving magnetic field in the first part of each half cycle. This determines the direction the rotor starts to rotate. When the rotor is running at nearly full speed a speed sensing mechanism disconnects the start winding. The motor will continue to run. [I wonder, does this mean one magnetic field is weaker than the other and the stronger magnetic field forces the motor in a specific direction?]

SNIP

For multiple phase motors and the [sic] means three, it's the order of how the three phases are wired… it rotates the direction of the phase rotation.

Here is another blurb on how single phase motors figure out which direction to spin. It's worded slightly different

Source

SNIP

A capacitor in series with the start wiring produces a phase shift , or a shorted (shaded) turn exploits magnetic effects to produce a phase shift.

[I think what they are saying is the cap causes the magnetic field in one set of coils to be slightly out of sync with the magnetic field in the other coil, and thus forces the motor to rotate in a specific direction at start time - gotta think about that in my brain for a second or two]

[Or maybe as I said before is one magnetic field weaker than the other magnetic field and that forces the motor to spin in a specific direction?]

One more article on how an AC motor figures out it's direction at start time

Source

SNIP

To reverse rotation on a single phase capacitor start motor, you will need to reverse the polarity of the starter winding. This will cause the magnetic field to change directions, and the motor will follow. In order to achieve this, you can swap the connections on either end of the winding.

SNIP

On Sunday, July 14, 2019 JJ gave me two documents on this and I used them to do these calculations.

Those articles are titled

CD-ROM Sensored BLDC motor control with Arduino - Simple Projects

Sensored brushles DC motor control with Arduino - Simple Projects

There are two items on this.

First you can use the 3 hall effect sensors, which if you use 1 for on and 0 for off you can use to generate a binary number of 1 thru 6 for each of the 6 steps you cycle thru on a rotation of the motor.

Second for each of those 6 steps you have for the pins that send voltage to the motors

1 pin or phase will be set to (+) or a positive voltage

1 pin or phase will be set to (-) or a negative volatage

1 pin or phase will not be turned on.

You can use the 3 numbers from the hall effect sensors to generate a binary number of 1 to 6 to tell which phases of the motor to turn on.

In these two article the phases are labeled A, B and C rather then 1, 2 and 3 in the other documentation.

The number is a 1 or one if the hall effect sensor is on and 0 or zero if the hall effect sensor is off.

These are the voltages applied to each pin or phase.

The data in I calculated in the previous two tables are from page 2 of the articles I mentioned above.

This is done 6 times per revolution.

I.e, phase 1 & 2 will be fired at the same time with phase 1 being hooked to positive and phase 2 hooked to negative.

Then that is repeated for phase 1 & 3, and finally for phase 2 & 3.

Then for the next 3 cycles of the 6 cycles in a revolution, positive and negative will be reversed for the connections.

Such as in the prior example in table 20.

Here table 20 is shown again.

This video and web page describes a slightly different scheme where in 3 of the 6 cycles, current is run thru 2 of the phases at t he same time.

I.e. run current thru A to B, A to C and B to C. Or perhaps from A & B to ground, A & C to ground and finally B & C to ground.

While in the remaining 3 of the 6 cycles current is only run thru one of the phases at a time.

I.e. run current thru only A, B or C.

And in these 3 cases the only place for the current to leave A, B or C is via the ground wire.

From the website and video, I couldn't figure out which phases were hooked to positive, negative or ground, so I just put an X in the cell to show it was being used.

Which gives us this table 21, which is a slightly modified version of table 20.