PWM water pump control

[dll67]

Probably worth talking to Meziere. I remember them not recommending using pwm control on the smaller 20gph pumps.

This is the WP361 55GPM

FETspeed.jpg

Here's the new schematic with previously discussed components

[dll67]

Comes on before any trigger signal .. as soon as the Fuel pump relay picks up? What did I do wrong ?
Day 2 circling the bowl

[racingmini_mtl]

If you're using the medium current outputs, you need to omit the TIP122 and the 330R resistor. The circuit on the MS3X already does the job. So simply connect the 39R resistor and the IRFZ46 gate (1) to the MS3X output.

Jean

[dll67]

If you're using the medium current outputs, you need to omit the TIP122 and the 330R resistor. The circuit on the MS3X already does the job. So simply connect the 39R resistor and the IRFZ46 gate (1) to the MS3X output.

Jean

Does this look right?

FETspeed2.jpg

[racingmini_mtl]

Yes.

[dll67]

Ok .. Now were getting some where.
Now it pulses with the settings in CAN-bus test modes/Output test mode-I/O.
Only hitch is as soon as I activate the fuel pump relay the pump comes on .. If I turn the pump on it goes off and when I turn it off the pump comes on .. But it does sllow when I increase the duty time and also changes speed with frequency ... THats progress

[racingmini_mtl]

This circuit inverts the output signal, so if the output is off, the pump is on and vice-versa. That means you will need to invert your output in your settings and how you do that will depend on how you control the pump in the MS3.

Jean

[dll67]

I plan on using the Generic PWM. I can work with that .. I planned on having the pump run slow at startup, increasing speed as engine temperature increases. Ill have to invert my water pump dash indicator is all.
Thank you Jean this will help several people who want to accomplish pump control.

[dll67]

Ok .. I'm not liking this inverted thing. Im having to invert the curve on generic pulse width settings. Is there a way to modify the circuit and/or use my IOx to remove the invert and get the frequencies the pump will be happy with .. The 250hz maximum using the ms3x is going to be hard on the pump.

[dll67]

Would using a P channel mosfet on the high side instead of n channel mosfet on the low side stop the output from being inverted?
If so how would the circuit design need to be changed?

[jb007]

dll67, I hope you don't mind me jumping in on your thread, but I think we both have similar issues.

After wrestling with my Morris Mini upgrade project today (see my Blog), I decided to test the two PWM O/P's I intend to use i.e. The fuel pump and pressure settings for a returnless fuel system and the generic PWM output A for a coolant fan control. Both using a Crydom D1D20 SSR that can handle up to 3,500Hz switching frequency. Well within the max that the ECU can do now (250Hz).

I bench tested using the JimStim, and used a 12V motor that pulls around 18W unloaded and the above SSR and bench power supply along with my DSO.

The PWM Fuel Pump & Pressure settings seem to work as intended. I might have to had to invert the O/P though, which It allows. Without a feed back element directly connected it's impossible to see if the the PID is working well. I used a spare pot on the JimStim to replicate the 30PSI fuel sensor I am using on the car. Anyway so good.

With the Generic PWM Output A, I had to invert my curves Duty Cycle, as there is no software facility to invert the O/P (I'm using FIDLE). Not a show stopper, but would be easier to read the right way around!

James, If your'e reading this, firstly is there any chance of a invert O/P option? Secondly can the switching frequency be upped at all, or is there a hardware limitation?

[dll67]

dll67, I hope you don't mind me jumping in on your thread, but I think we both have similar issues.

After wrestling with my Morris Mini upgrade project today (see my Blog), I decided to test the two PWM O/P's I intend to use i.e. The fuel pump and pressure settings for a returnless fuel system and the generic PWM output A for a coolant fan control. Both using a Crydom D1D20 SSR that can handle up to 3,500Hz switching frequency. Well within the max that the ECU can do now (250Hz).

I bench tested using the JimStim, and used a 12V motor that pulls around 18W unloaded and the above SSR and bench power supply along with my DSO.

The PWM Fuel Pump & Pressure settings seem to work as intended. I might have to had to invert the O/P though, which It allows. Without a feed back element directly connected it's impossible to see if the the PID is working well. I used a spare pot on the JimStim to replicate the 30PSI fuel sensor I am using on the car. Anyway so good.

With the Generic PWM Output A, I had to invert my curves Duty Cycle, as there is no software facility to invert the O/P (I'm using FIDLE). Not a show stopper, but would be easier to read the right way around!

James, If your'e reading this, firstly is there any chance of a invert O/P option? Secondly can the switching frequency be upped at all, or is there a hardware limitation?

Jim,
Yes we are .. Frequency .. 250hz .. That's a problem .. We both need more and it's been asked if we can get more .. I don't have the link too the thread where the question was asked. The answer was no. Might have since changed but probably not
Other option Jean has a pwm converter that will multiple the frequency or his I/o expander will also do the same thing a little different way. Both will easily get to the 500-1500hz we need.
As far as the inverted output .. It's causing me problems and headaches. I don't yet know a way tio invert it by software or hardware

[jb007]

dll67, I hope you don't mind me jumping in on your thread, but I think we both have similar issues.

After wrestling with my Morris Mini upgrade project today (see my Blog), I decided to test the two PWM O/P's I intend to use i.e. The fuel pump and pressure settings for a returnless fuel system and the generic PWM output A for a coolant fan control. Both using a Crydom D1D20 SSR that can handle up to 3,500Hz switching frequency. Well within the max that the ECU can do now (250Hz).

I bench tested using the JimStim, and used a 12V motor that pulls around 18W unloaded and the above SSR and bench power supply along with my DSO.

The PWM Fuel Pump & Pressure settings seem to work as intended. I might have to had to invert the O/P though, which It allows. Without a feed back element directly connected it's impossible to see if the the PID is working well. I used a spare pot on the JimStim to replicate the 30PSI fuel sensor I am using on the car. Anyway so good.

With the Generic PWM Output A, I had to invert my curves Duty Cycle, as there is no software facility to invert the O/P (I'm using FIDLE). Not a show stopper, but would be easier to read the right way around!

James, If your'e reading this, firstly is there any chance of a invert O/P option? Secondly can the switching frequency be upped at all, or is there a hardware limitation?

Jim,
Yes we are .. Frequency .. 250hz .. That's a problem .. We both need more and it's been asked if we can get more .. I don't have the link too the thread where the question was asked. The answer was no. Might have since changed but probably not
Other option Jean has a pwm converter that will multiple the frequency or his I/o expander will also do the same thing a little different way. Both will easily get to the 500-1500hz we need.
As far as the inverted output .. It's causing me problems and headaches. I don't yet know a way tio invert it by software or hardware

Mmmm I don't want to add more hardware at this late stage. I can get by by inverting my curve for the generic pwm o/p and use the inverted option for the fuel pump control.
It would be good to have the option of inversion for all the generic pwm o/p's.
I've been reading up on how to select the best PWM frequency for a DC motor, there seems to be so much debate about it! Some say low frequencies give a large dynamic range and low down torque... maybe 250Hz is OK. I'll find out when I fire up my car very soon!

Thanks, for your feedback... it's midnight here... time to sleep.

Jim

[dll67]

For when you wake ..
I've read with in regards to frequency .. Every motor likes something a little different. Symptoms noise and heat .. Detrimental affects .. Motor life and efficiency from high heat. Fuel pump inside a tank probably will cool the pump enough heat or noise won't be a big problem. External fuel pump .. Should be able to find a happy frequency for out much easier .. From reading .. most pumps fall into the 500-1500hz range. To low you get heat and to high you loose efficiency .. I'm guessing power to at the extremes

[dll67]

Like Jim asked .. Inverting output .. Fuel pump outputs can how about the medium pwm outputs on the ms3x?
Frequency outputs .. Still limited to 250hz in the ms3?

[jsmcortina]

Like Jim asked .. Inverting output .. Fuel pump outputs can how about the medium pwm outputs on the ms3x?

I'll have a think about it.

Frequency outputs .. Still limited to 250hz in the ms3?

Sure thing!

James

[jb007]

Gooday.

You know, it sometimes pays to sleep on a problem, which is what I've done.

Last night I'd connected the PWM O/P to the +ve and Gnd to the -ve terminals of the SSR, and had to negate the signal in the Pump section and reverse the duty curve in the Generic PWM A section.

Doh!. All I had to do to fix this for both PWM's is hook the PWM to the -ve and +5V to the +ve terminals, bingo! All fixed now.

Of course this doesn't help you dll67, or others that have a MOSFET controller, so I would like if possible for the Generic Output's to have an invert O/P option if possible.

Hopefully next time I will be testing the Fuel PWM PID controller on the car, I've a bit of reading up on how to tune a PID controller... does anyone have a simple howto?

Cheers,

JIm

[jb007]

Hi dll67. How did you go with the PWM etc? I was just wondering if you are still having trouble,as this thread has gone very quite! If your having trouble still have you thought of going the SSR route?

I'm very close to powering up my PWM returnless fuel system, maybe this Sunday, if not Tuesday or Wednesday.

[dll67]

Jim,
I finished the small circuit to switch the water pump and had it working through the ms3 but was un happy with the max 250hz. Now I'm using my iox board from Jean which has infinitely larger frequency options for controling the pump. Just working on hammering out the iox configuration.
Here's a link to the thread http://forum.jbperf.com/viewtopic.php?f ... 4&start=20

[jb007]

Jim,
I finished the small circuit to switch the water pump and had it working through the ms3 but was un happy with the max 250hz. Now I'm using my iox board from Jean which has infinitely larger frequency options for controling the pump. Just working on hammering out the iox configuration.
Here's a link to the thread http://forum.jbperf.com/viewtopic.php?f ... 4&start=20

Thanks for that. I looK forward to seeing it going just like I hope mine goes! Cross your fingers for me.