Help for motor connections of a six wire motor

[ozgur84]

Hello everybody,

I opened an old cd driver and found a six wire motor in it. it is a sanko 4a04604. I googled it but i cannot find information about the connections (actually i found almost nothing). I read an article about finding the pin out configuration and I measured the resistance of the wires with respect to each other. the result is (in ohm):

white blue yellow red brown black
white x 253 339 450 454 255
blue 236 x 253 278 283 171
yellow 310 339 x 459 450 249
red 430 274 434 x 358 274
brown 430 275 434 364 x 285
black 274 165 242 274 275 x

there are also 2 extra wire are not connected to the same connector and when I applied a DC voltage to those wires the motor works like a normal DC motor...

I also read in the same article that if the motor is 6 wire DC motor, there must be some connections which have infinite resistance.

Can anyone help me out about this connections? if it is a 6 wire stepper I want to use it in a project.

Regards

 

[Mr RB]

It sounds like a dc motor (which is why it spins when you connect power to the 2 "special" wires), with some type of encoder mounted on the end, which has all the "other" wires.

A photo will be very helpful.

 

[KeepItSimpleStupid]

A quadrature encoder? You would have at least 2-4 for two LED's and 3-4 leads for photo-transistors, so 3 and 3 would make sense.

Check for diode behavior using the diode scale.

 

[ozgur84]

It sounds like a dc motor (which is why it spins when you connect power to the 2 "special" wires), with some type of encoder mounted on the end, which has all the "other" wires.

A photo will be very helpful.

A quadrature encoder? You would have at least 2-4 for two LED's and 3-4 leads for photo-transistors, so 3 and 3 would make sense.

Check for diode behavior using the diode scale.

The photo is here. I think you are right, these six cables are something else but the motor connections. And the motor is actually is a simple DC motor...

 

[Mr RB]

Thanks for the photo, it helps a lot!

That seems to be a magnetic encoder, the black plastic circle will have magnetic poles in it, and on the top green PCB with the 6 wires will be a number of SMD hall effect sensors, acting as a rotary encoder.

Analog hall sensors in motors usually have 4 wires each, so I think they might be 2 digital hall sensors, (each has 3 wires power, ground and output) and they are likely aligned as a quadrature encoder.

If you could press off the black disc the sensors would be fully visible and you would know for sure, but pressing off that disc will likely destroy the motor or disc.

 

[shortbus=]

If this was a CD player spindle/platter motor, wouldn't the encoder have been used in its speed control circuit?

 

[Mr RB]

Yes it would have. It's not necessary have quadrature for that, or even to have any speed feedback on the platter motor. Most CD players get feed speedback from the data coming from the laser head and just use a simple DC motor for the platter.

Anyway it's a cool motor and should be usable for some precise speed-regulated task (like a POV propeller clock etc).

 

[ozgur84]

Yes it would have. It's not necessary have quadrature for that, or even to have any speed feedback on the platter motor. Most CD players get feed speedback from the data coming from the laser head and just use a simple DC motor for the platter.

Anyway it's a cool motor and should be usable for some precise speed-regulated task (like a POV propeller clock etc).

thanks for your answers, but I was totally off after you started discussing this encoder thing , I know what is a hall effect sensor but I do not know about encoders or so...anyway, the result is; this is obviously not a 6 wire stepper motor by the way this is not the motor which turns the disk in the cd drive. I has something to do with laser head...