Use PWM to control your Jebao DCT pump using brushless motor controller from ebay

[d0ughb0y]

I was thinking more of how the max setting between the 2 compares, since you mentioned the fish-street T1 can drive the pump 120% (120% more flow than stock controller that is).
As these are BLDC motors, the amount of flow is proportional to the rpm and is proportional to power usage. And if you can get a hold of a T1, you can measure and verify if the claim is true or not.

[karimwassef]

good point. I need to find someone local with a T1 since I'm not spending that much for a test

[karimwassef]

ok so here are the actions/tests for this weekend:

1. set up the Apex connection on a VDM so I can run two pumps at the same time.
2. measure the current on a brand new jebao controller and measure the associated flow for each of the setpoints. (new/new)
3. measure the current and flow on the new jebao controller with the old pump at the same setpoints. (new/old)
4. measure the current and flow on the Apex/driver with the new pump for different 0-5V setpoints. (apex/new)
5. measure the current and flow on the Apex/driver with the old pump for different 0-5V setpoints. (apex/old)

Then I'm going to create a phased flow with the two pumps out of phase and run them off one power supply... that's my actual application

I think that'll cover all the questions for now?

for the Apex-driven voltages, I'm thinking:

0.00
0.50
1.00
1.50
2.00
2.50
2.75
3.00
3.25
3.50
3.75
4.00
4.25
4.50
4.75
5.00

I suspect that the 2.75 to 5.00 (10 settings would line up with the native controller's setpoints). I could open it up and just measure it, but I'd rather not.

That would correspond to the Apex running

0.0
1.0
2.0
3.0
4.0
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0

[d0ughb0y]

I used a killawatt and compared the power usage of the green board to the stock controller. Green board uses 25 watts, stock controller uses 35 watts. There may be difference in the flow, but it is hard to quantify. The stock controller with all 10 leds on will probably pull a few more watts, but I was not expecting 10watt difference.

Maybe when you do the comparison, you can test say time to fill up a 5 gallon bucket in order to quantify any difference in flow.

[karimwassef]

that's exactly how I was going to test flow. GMTA man!

[d0ughb0y]

I connected the white motor controller, and it uses 35 watts as well. I will try to resolder the connecting wires to the green board to see if it makes any difference.

[karimwassef]

ok. Here's the first batch of results. Either the Jebao native controller is a power hog, or it does create more drive. Tomorrow, I'll try and get the green controller wired to my Apex to test.

So - first the setup:



basically, I let the run pump in a closed loop to get to full speed and stabilize the current consumption. Then I use a sliding gate valve to suddenly shut that path off and simultaneously push the timer on the stopwatch. When the water level in the 5 gal bucket crosses the 5 gal mark, I stop the watch and take the reading. The container around it is because I didn't want to be focused on reopening the gate valve. It's secondary to catching the stopwatch reading so I needed some protection in case the bucket overflowed.

Then reset and repeat...

Here's an example reading



and the results



So there's a little drift in the 1-10 relating to power drive, but overall, the power and flow line up. The old pump just seems to have more power for the same set point.

I'm sure there's some pump to pump variability.

[d0ughb0y]

that is all using the green controller board right?
what does the 15000 pump specs say for flow at 3' or about 1meter?
If you test with stock controller, you'll be able to confirm if the pump is over rated or not.
your power reading seems to match the specs 105watts.

[karimwassef]

No. This is with the native Jebao controller

[karimwassef]

So 1m ~ 11,500 liters per hour ~ 3000 gph

With the Jebao controller on 10, I peaked at ~2600 gph. That's off by 13% from the advertised rating but it may be limited by the controller

[d0ughb0y]

I think that flow is fine compared to the chart.

I'm curious to see if the green board generates a comparable amount of flow. I think from your chart, it uses 70-80 watts at max.

[karimwassef]

We'll find out tonight. I set up the new VDM module. Still need to make the cables.

I think the difference in flow is ok given that my flow measurement error increases at high flow rate because 5gal is a very small volume at 2600gph, so fractions of a second errors are more impactful.

[karimwassef]

Btw, measuring flow is a PITA! But I'll do it for the common good.

[Dactylopterus]

I think the pump flow is meassured without any back pressure other than the height. Your setup has two elbows creating a lot of back pressure. Your measurements show that the flow of these pumps may be rated correctly.

[karimwassef]

Got the Apex control working and able to provide 0-5VDC (0-100 APEX signal).

Unfortunately, at APEX=100 (drive signal = 5VDC), the current draw is only 2.8A @ 24.3V and I can tell that it's not as strong as the native Jebao controller.

I'm going to try using the 5VDC output on the controller itself to see if I get anything different.

[karimwassef]

running off the internal 5VDC only increases the current draw slightly up to ~3A (maybe 3.07A max) . I checked the signal and it's 5.00V.

It's a far cry from the native controller's 4.57A for the same pump.

Going to baseline the native controller again just to see if anything's changed.

[karimwassef]

Jebao controller = 4.57A
Green controller = 3.07A

same conditions...

[seldon]

Have you tried measuring the current draw at the pump rather that at the wall? That way you can take out any controller inefficiencies.

[karimwassef]

The pump power is 3 phase square pulses. I would need to capture all 6 voltage and current waveforms and determine the RMS power.

[karimwassef]

I'm thinking of what to try next.

I can try the other pump, but their behavior was similar.

I can dig up my data acquisition USB board and wire it up to compare the pump waveforms.

I have two more green boards on the way... I can try them out.

I can add a plate and fan in case any component is thermally limiting output?

I can add a ferrite bead at the DC input to experimentally limit any noise going back to the power supply and limiting it?

[karimwassef]

Doughboy- ideas? There aren't many other control points that I see?

[d0ughb0y]

The only true way to compare is by flow.

On my setup, the stock and white controller runs the same 35 watts, and green 25 watts.

The stock and white controller both use transistor + N and P channel mosfet pairs, and the green uses IR2101 pre driver + N channel mosfet pairs. So it made sense that the white and stock controller showed the same power usage. Both white and green board are based on the same JY01 motor controller chip.

Both circuits are pretty standard and every article I read about BLDC driver uses one or the other circuit and I frequently see mention that the N channel pair circuit is better.

On my small pump, I can't tell the difference in flow. I take it on the bigger pump you are able to tell without doing a flow test right?

If that is the case, I can analyze the green board circuit further to see if any mod can be done.

FWIW, I think we both see about 25% less power on the green board from stock.

[karimwassef]

I didn't measure the flow because I could immediately tell that it was significantly lower.

I can run the test but I don't think it's worth it unless there's a path to getting more power into the pump

[d0ughb0y]

no need to run the test if you can tell right away.

I'll check if there is anything that can be done to improve it.
otherwise, I can still go back to my original plan to build a new board from scratch.

[karimwassef]

Or try another board vendor? If we're looking at a new board that would basically be a variant of this one, can we debug it and improve it's performance instead?