Author Topic: The desperate act of a scallywag  (Read 3017 times)

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Offline oztules

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The desperate act of a scallywag
« on: September 17, 2018, 11:51:51 pm »
So it has been a bit dry here of late, and the plants I planted out a few month ago are starting ( ending more likely) to look drastically thirsty.

The rain that was expected and then expected etc etc never came, so it was time to do something.... but I had no working DC pump, had given away the AC pumps, and really wanted a slow steady solar solution....... had none of that either.

I did have a BLDC motor I got many many moons ago to experiment with.... but no driver or pump to go on it.

I had done some work with the JY01 chip from China, and if it worked as well as the one from China that I use for the big inverters, it would be very nice.

So after some work we had a board. a motor, but still no pump...... then the desperate thoughts started..... what about .... nah... but then....

So after an hour we got this...... and it works perfectly first up.

7749-0

Yes that is what it looks like....... a diaphram pump head, a BLDC scooter motor, and a solar panel and JY01 controller I just built.

Looking closely, we can see what a horrid effort I did to cobble it all together...... but it does work.... honest....

This gets a little closer to the crime...... We can see I just threw the magnet body, rear brush housing out, and just kept the head. The armature is till there and we will see shortly why this motor did not work..... near new it was too.

7751-1


Note the wire wrapped around the armature brush area. The new motor let go of the wire, and it tangled in the rotor and ripped itself up a bit..... so it was no good anymore as a motor... thats for sure...... hence the devil may care attitude to the destruction of the motor pump assy.

7753-2

Here is the prototype controller. Direct to the solar panel, it has mppt set point via jumpers for different panel voltages up to 80v. It also has speed control max  pot.... so if your pumping from a slow source, you can turn it down to a max speed. This means if solar is not enough to get to max setting, it will do what it can, as the solar increases, it gets to the max speed, and any more solar will make no difference.

In this case, the design is so flimsy, I used this section to keep speed under harmonics that seemed dangerous.

If anyone wants design of the controller for BLDC solar pump , let me know and I will fast track it's article.

This controller does not use hall effect diodes, as most bldc bore pumps do not use them, and this was ostensibly designed to replace dead ones of those..... so just three wires. Don't know just how much power it can develop, but it has 200A 80v fets. I'm guessing 60-70v solar will get in the 1-1.5kw range, but have not tested it that far yet.... no load to try. That motor is supposedly 2kw... we'll see when I can find a load to try it on.... but I expect it to run 30 amps easy enough.

7755-3

This makes start up a bit twitchy sometimes, but it always gets the direction ok after a half a second or so if it is confused. Mostly it seems to luck the correct direction, and pretends it knew all along what it was doing.


Anyway, it just works very nicely :)

...........oztules
Flinders Island...... Australia

Offline noneyabussiness

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Re: The desperate act of a scallywag
« Reply #1 on: September 18, 2018, 04:27:10 am »
Love it Oz.. good job

Offline bj

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Re: The desperate act of a scallywag
« Reply #2 on: September 18, 2018, 05:19:09 am »
  Sure it will work for a long time.  Also sure the plants are thankful.
"Even a blind squirrel will find an acorn once in a while"
bj

Offline oztules

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Re: The desperate act of a scallywag
« Reply #3 on: September 18, 2018, 05:47:00 am »
Thanks,
I'm happy with the BLDC controller, I had always wanted to build a hall less controller like that, and envisaged that it could take the place of the commercial controllers if they should fail in the summer.... thirsty cows take no prisoners.

And it does work extremely smoothly thus far. Will see tomorrow if we have better light.

The pump on the other hand is a dreadful looking device, but funnily enough works... not sure for how long. I think I am losing some volume because of the rubber mounts, but these are necessary to stop it vibrating to bits if it were rigidly fixed.

But because of this flexability, it's stroke is compromised. Luckily time is on the side of the sun, as it can run all day , and at lower volume.... or I can wind up the speed... We will see just how smart we were/not.

It it continues to perform as it seems, I will upgrade the fets to 150v or more, and get a bit more interested.


...........oztules
Flinders Island...... Australia