Adding sensors to a Astro 3210 motor

[drewjet]

Ok so I got my hall sensors from Mouser http://www.mouser.com/Search/ProductDet ... ey785-SS41 I hooked them up with the chamfer facing up neg at center, pos to the left and signal to the right. I can't get them to turn on. I tried 4v 6v 8v 12v. I have a hall from an old motor and it works just finejust like that. I tried 6 of them and none worked.

Am I doing something wrong, did I get the wrong ones. or did I get a bad batch?

[Burtie]

Do you have a pullup resistor on the signal lead? Without this the signal will never go high.

Must limit the current to less than 20mA, so something like 1 or 2k would do.

[drewjet]

No I don't have a resisitor on the signal lead.

So just add a 1K resistor inline with the signal leg?

[methods]

No - there is no active output from this sensor

Think of the hall sensor as a BJT
The collector is the signal lead
The emitter is tied to ground
When the magnetic field is present it runs current into the base and connects the collector to the **** (edit emitter)

Long story -
You need to "pull up" the signal line
This means that you need to tie a 1K resistor between 5V and the signal line
This will output 5V - then when the sensor becomes active it will "pull down" the voltage to 0V


-methods

[methods]

BTW: If at any time you accidentally tie +5V directly to the signal line it will destroy the sensor. As suggested above, the current must be limited to 20mA

5V / 1k = 5mA

That is why a 1K resistor was suggested. Enough current to bias the sensor and raise the noise floor but not so much that it overheats from too much current.

If you use higher voltage - like 10V - you must also use a higher resistance

10V / 2K = 5mA

Make sense?

-methods

[drewjet]

Ah, that makes sense now thanks for the explanation.

Interesting that the hall I pulled out of my dishwasher motor did not need the resistor. It simply either turned power on or off.

Is the resistor is only needed when testing? When hooked to a speed control it is not needed, is that correct? Thanks for helping the electronically challenged.

Drew

[gwhy!]

Hi DJ,
Most controllers have these pull up's built into the controller so you do not have to worry about them.

[Scorefield]

Looking forward to see it running and hope everything will go well.
Anyone got a video soon please.
coughInfineon.

[Burtie]

The sensored astro seems to work ok on the bench

I still have a few small tweaks to do to the sensor plate design, but it seems good so-far:

http://www.youtube.com/watch?v=AbCYDYIFW80

[liveforphysics]

Burtie! You're awesome! Great work!

[AussieJester]

Burtie! You're awesome! Great work!

+1 you da man Burtie!

KiM

[Scorefield]

Holy smoke, I just fell down off my chair
You are awesome..
Thanks a lot for the vid.*jumping up and down*

[Burtie]

Thanks for the encouragement guys!

I tried the same trick with the motor wired delta and made the following observations:

1) The hall sensor group needed to be moved by about 12 (mechanical) degrees to minimise the no-load current in delta.
See angle between pen mark and securing tab. Without this adjustment, the motor ran slowly, was very noisy and took 6 amps unloaded.

2) There seemed to be no acceptable compromise between the delta and wye hall group positioning that would work well for both configurations.
In a position mid way between the two, the no load Y current was almost double at 1 amp.
( I guess sensorless controllers do have some good points )


3) I saw the same expected efficiency loss due to recirculating currents in delta as discussed here:

viewtopic.php?f=28&t=13760&start=45#p244398

The no-load current was 3.5 amps in delta, as opposed to 0.6 amp in wye, even after the timing had been adjusted.

[kevo]

Very awesome Burtie! Are kits for other Astro owners in the future?

Thanks for all,
Kevo

[12p3phPMDC]

Great Reporting Burtie!


Sensorless controllers automatically discover the timing due to back emf.
Sensored controllers start better....
So, If we could only run sensorless in Delta and sensored in Y.
You can start with a lower Kv in Y, and switch to Delta when you want to switch.

It would be cool to have a controller with adjustable timing tables with a digital input
that will switch between tables or static advance or retard settings.

Ah....no free rides ever, especially when you are trying to get the most out of something.

It reminds me of the timing tables in an ICE engine controller. The two controllers
that I've setup both have timing tables that allow one to advance or retard the timing based
on speed. It would be very flexible even if all you needed was static advance/retard but
could optimize with a table vs speed. (edit: Tables are two-d with load/vacuum/or throttle position too).

[Burtie]

Hmmm, -ebike controller with adjustable timing tables, sounds like a nice idea!

Anyone out there fancy a PIC / Infineon firmware project?? could integrate the D-Y switch in the FET output stage as well

Hell, I might even have a crack at it one day, but it wont be quick!

As an interim solution I wondered about more slots in the plate for a second hall group to run delta. Could parallel the outputs of the two hall groups and just turn on power the group that was required

Burtie.

[Burtie]

Very awesome Burtie! Are kits for other Astro owners in the future?

Thanks for all,
Kevo

Hi kevo,
Yes I will look into the cost of getting a number of these discs and plates made up soon, as a sort of kit

Burtie

[Ypedal]

Put me down for one !

[johnrobholmes]

Same here, I want!

[Scorefield]

Put me down for one !

Same here, I want!

Sign me up for one, please.

[matt_in_mtl]

Hmmm, -ebike controller with adjustable timing tables, sounds like a nice idea!

Anyone out there fancy a PIC / Infineon firmware project??

You mean something like this?
http://scolton.blogspot.com/2010/01/3ph-duo-wrap-up-part-1-field-oriented.html
A very interesting read, he is going a couple steps further too though.

Very cool results Burtie, very cool!

-Matt

[Burtie]

Good find Matt,

We need that guy here with us on the sphere!



On the subject of cooling, -If you can't fix the cause, then just treat the symptoms:

How about these fins to dissipate the heat generated by those recirculating currents

They are the ones that Cyclone sell to keep their heat problems in check. Almost perfect fit on the astro.

Astro fins.jpg (101.84 KiB) Viewed 461 times

[kevo]

Burtie,
You are another hero in the Endless-Sphere among us lesser mortals!
Definitely sign me up for your Hall Sensor holder when they become available.

Regarding using Cyclone heat sinks for Astros, doesn't Cyclone only sell these with their Cyclone kits?
Is there an alternative way to just buy the heat sinks for us Astro folks?

-Kevo

[dbaker]

Burtie,

Great work! I am waiting for a 3220 to arrive and am interested in a kit. I already got the Hall sensors.

Dave

[Grinhill]

Is there an alternative way to just buy the heat sinks for us Astro folks?

-Kevo

Hey Kevo, Recumpence made some heatsinks for Astros a while back, send him a pm, he may still have some.