Use PWM to control your Jebao DCT pump using brushless motor controller from ebay
- Thread starter d0ughb0y
- Start date
d0ughb0y
Active member
I compared the signals between the boards, and the white and green board signals are actually similar, which makes sense since they both have the same chip and bemf circuit is identical.
The problem seems to be the ebay board is skipping one commutation (you can see that in the logic analyzer signal I posted above), so instead of on, off, on, off, on, off it gets on, off, off, on, off, off. Thus is getting less power.
I have to figure out why it is commutation signal is skipping and if this can be fixed by component change.
The problem seems to be the ebay board is skipping one commutation (you can see that in the logic analyzer signal I posted above), so instead of on, off, on, off, on, off it gets on, off, off, on, off, off. Thus is getting less power.
I have to figure out why it is commutation signal is skipping and if this can be fixed by component change.
karimwassef
Active member
Do you still want me to try the resistors and diodes? It's been a busy week - quarter close today.
d0ughb0y
Active member
karimwassef
Active member
Ok. Let me know.
d0ughb0y
Active member
This is the jebao BEMF signal.
They are longer and overlaps. That's how it should be.
This is from the ebay controller. They are shorter and don't overlap. So the coils are not energized as long.
So I need to find a way to make the ebay controller BEMF signal be like Jebeo's.
They are longer and overlaps. That's how it should be.
This is from the ebay controller. They are shorter and don't overlap. So the coils are not energized as long.
So I need to find a way to make the ebay controller BEMF signal be like Jebeo's.
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d0ughb0y
Active member
Karim,
can you try to connect
MA - U
MB - V
MC - W
I think that fixed the problem. I only tested on the white board. The killawatt reading went from 35watts to 45 watts.
I have to desolder the cable from the green board to test this on the green board.
Just checked my connections again. It should be as shown in the green board connection picture on page 1. I had switched U and W.
can you try to connect
MA - U
MB - V
MC - W
I think that fixed the problem. I only tested on the white board. The killawatt reading went from 35watts to 45 watts.
I have to desolder the cable from the green board to test this on the green board.
Just checked my connections again. It should be as shown in the green board connection picture on page 1. I had switched U and W.
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d0ughb0y
Active member
I just rewired the connection on my green board, and now I am getting 37 watts reading on the killawatt, and the BEMF signal now overlaps, but the flow seems even less, and the pump makes a whining noise. Tomorrow, I'll try all 6 combinations of connections and see which one works best..
I just shined a flashlight on the pump outlet, and the connection UVW-ABC spins in reverse. Somehow the water still comes out the outlet. That's whats causing the whining noise, and less flow. With the original connection, I can see the pump spin the same direction as the stock controller.
I just shined a flashlight on the pump outlet, and the connection UVW-ABC spins in reverse. Somehow the water still comes out the outlet. That's whats causing the whining noise, and less flow. With the original connection, I can see the pump spin the same direction as the stock controller.
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karimwassef
Active member
Any updates?
d0ughb0y
Active member
none since my last update. I will try all 6 WVU-ABC connections to see which one is really the right connection. If that does not help, my next step is to try to modify the BEMF ciircuit and change it so it is like the one on the stock controller. Are the resistors 0603 or 0402 size? I need to get 50k smd resistors to modify the circuit. If modifying the circuit works, it would not be a practical mod.
I know I don't have the capabilities to work with SMD devices.I tried once for a project I did in college, It didn't turn out too well. Hopefully its just the connections.
karimwassef
Active member
Just because the existing implementation is SMD, we can still use wire resistors. Machine placement only matters if you're making hundreds of boards but if it's one two, a little elbow grease is ok.
here is what I found:
UVW: spins backwards, draws 1.5 amps, bad flow, very noisy.
WVU: draws 1.13 amps. decent flow, somewhat noisy.
UWV: spins backwards, draws 1.5 amps, bad flow, very noisy.
VUW draws 1.23 amps, flow seems to be almost as good as stock controller, more noise than stock controller.
UVW: same as above.
WUV: spins backwards, draws 1.5 amps, bad flow, very noisy.
All configurations make the pump wine much louder than with the stock controller. Also, when I try to adjust the speed with the VR input, the pump doesn't really adjust speed smoothly. Seems to struggle with keeping up with RPMs.
UVW: spins backwards, draws 1.5 amps, bad flow, very noisy.
WVU: draws 1.13 amps. decent flow, somewhat noisy.
UWV: spins backwards, draws 1.5 amps, bad flow, very noisy.
VUW draws 1.23 amps, flow seems to be almost as good as stock controller, more noise than stock controller.
UVW: same as above.
WUV: spins backwards, draws 1.5 amps, bad flow, very noisy.
All configurations make the pump wine much louder than with the stock controller. Also, when I try to adjust the speed with the VR input, the pump doesn't really adjust speed smoothly. Seems to struggle with keeping up with RPMs.
karimwassef
Active member
I've been running WVU
<a href="http://s1062.photobucket.com/user/karimwassef/media/0_zpsye5ajie2.png.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/0_zpsye5ajie2.png" border="0" alt=" photo 0_zpsye5ajie2.png"/></a>
how much louder and more powerful is VUW or UVW compared to WVU?
<a href="http://s1062.photobucket.com/user/karimwassef/media/0_zpsye5ajie2.png.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/0_zpsye5ajie2.png" border="0" alt=" photo 0_zpsye5ajie2.png"/></a>
how much louder and more powerful is VUW or UVW compared to WVU?
d0ughb0y
Active member
That looks right that 3 of the connections make the pump spin in reverse.
One more thing to try though is with one of the connections that runs the pump in reverse, connect the Z/F direction pin to 5v to make it reverse, hence making it run in forward direction.
I am thinking since the wiring that runs reverse use a higher current, if it maintains the higher current but runs in forward direction, that would give the best flow.
The commutation signals of the lower current (forward spin) do not overlap, the signal looks more like ON-OFF-OFF-ON-OFF-OFF.
On the reverse spin, the signals look like ON-ON-OFF, ON-ON-OFF, hence the higher current.
From what I understand, to reverse spin, you simply reverse the sequence of commutation signal. So if that is the case, the signal for each line will still be ON-ON-OFF, but in reverse sequence, so pump runs in forward direction at higher current. At least that's what I am hoping.
One more thing to try though is with one of the connections that runs the pump in reverse, connect the Z/F direction pin to 5v to make it reverse, hence making it run in forward direction.
I am thinking since the wiring that runs reverse use a higher current, if it maintains the higher current but runs in forward direction, that would give the best flow.
The commutation signals of the lower current (forward spin) do not overlap, the signal looks more like ON-OFF-OFF-ON-OFF-OFF.
On the reverse spin, the signals look like ON-ON-OFF, ON-ON-OFF, hence the higher current.
From what I understand, to reverse spin, you simply reverse the sequence of commutation signal. So if that is the case, the signal for each line will still be ON-ON-OFF, but in reverse sequence, so pump runs in forward direction at higher current. At least that's what I am hoping.
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karimwassef
Active member
oooo smart.. worth a try.
Ill try that. What about the louder wining noise from the pump? Any explanation?
Its pretty much the same but you deff can notice the difference in flow. That setting doesn't seem correct to me. I have my pump setup to flow water through a piping setup I made.
