About stirrer

[jmcadsl]

Hi again!!!

I have a question about the use of the stirrer function.
I have 4 dosing pumps with 4 stirrers.
The connection for the pumps its ok, but the question its about stirrer.
In the manual i saw i must use ports 9-10-11-12 of the led outputs, then my question its...
Can i take Ground from the connexion DC Grounds at the left side?
I suppose i will have 5v in every stirrer channel?

Thanks!

[Rob F]

Hi Jmcadsl, yeah you can use LED channel 9-16 for stirrers, but they can't be connected directly to the stirrer motor, that could damage them.

The LED channels do put out a 0-5v PWM signal but that's only used to control a MOSFET which is required to handle the load of the motor. The output of the MOSFET would be the GND, you only need a GND from the controller for the MOSFET and you can use any GND pin on controller.

Here's a diagram for connections, any MOSFET will work as long as its Logic type.

http://www.me.umn.edu/courses/me2011/ard...-motor.jpg

[jmcadsl]

Ok.
I understand!
Thanks

[Rob F]

Also when the stirrer is enabled the PWM puts out the full 5v, if you want to slow down the speed you can adjust it in the code, if you need to let me know.

[jmcadsl]

Thanks!

[Dom59]

Hello Rob,

I am making a diy stirrer with a 12v fan.
I guest I can simply connect it on DC plug and schedule it on, just before running dozing pump.
But That fan has a PMW wire, so i need to plug it on led Chanel 13. As it is on 12V do I need to use the mosfet tip120?
Rgds
Dom.

[Rob F]

Hi Dom, you could use a DC plug and schedule it but the dosing system does have a stirrer option built it which uses the LED channels 13-16 which is perfect as you have a fan that uses PWM. If your fan was only regular 12v type you would need a mosfet but not for the PWM fan. You should be able to connect the PWM wire of fan directly to LED channel 13 (dosing pump 1) and then go to settings, hardware, dosing pumps, advanced options and enable the stirrer. With this enabled when dosing starts the stirrer will run first for 10 seconds, then settle for 12 seconds and then the pump will come on. Can't change these on display yet but if you want to I can tell you where in sketch to change.

Before you change the setting you can test the fan by going to the lights page and moving the slider for channel 13. The PWM from the controller is 0-5v, your fan could be that or 0-10v, if it's the latter the max speed will be 50%. You would need components to convert to 0-10v if needed.

You can power up the fan, guessing 12v, using the power pins on controller, if you use external power supply remember to connect GND to controller for common GND.

[Dom59]

Hi Dom, you could use a DC plug and schedule it but the dosing system does have a stirrer option built it which uses the LED channels 13-16 which is perfect as you have a fan that uses PWM. If your fan was only regular 12v type you would need a mosfet but not for the PWM fan. You should be able to connect the PWM wire of fan directly to LED channel 13 (dosing pump 1) and then go to settings, hardware, dosing pumps, advanced options and enable the stirrer. With this enabled when dosing starts the stirrer will run first for 10 seconds, then settle for 12 seconds and then the pump will come on. Can't change these on display yet but if you want to I can tell you where in sketch to change.

Before you change the setting you can test the fan by going to the lights page and moving the slider for channel 13. The PWM from the controller is 0-5v, your fan could be that or 0-10v, if it's the latter the max speed will be 50%. You would need components to convert to 0-10v if needed.

You can power up the fan, guessing 12v, using the power pins on controller, if you use external power supply remember to connect GND to controller for common GND.

https://docs-emea.rs-online.com/webdocs/...3cd050.pdf

 I have got that 12v fan. I connected it at 12v and ground pins on board and signal (brown wire) on 13rd led Chanel. The speed is variable but never stop when Chanel is at 0. Do I need to change signal power?and how?
Can you help me?

[Rob F]

So the fan changes speed but doesn't turn off? When moving slider up does speed increase or decrease? Did you check the voltage on channel 13 to verify it's 0 volts when off?

[Dom59]

So the fan changes speed but doesn't turn off? When moving slider up does speed increase or decrease? Did you check the voltage on channel 13 to verify it's 0 volts when off?

Speed increase when slider up. And there is 0v at 0%. I guess it’s an issue with that fan?

[Rob F]

Just noticed in the datasheet you posted, says this on page 1 under the specifications.

Note: Rated voltage 5V and 24V fans do not rotate when PWM duty cycle is 0％.

That implies the 12v fans do rotate when PWM is 0%, makes no sense.

[Dom59]

Just noticed in the datasheet you posted, says this on page 1 under the specifications.

Note: Rated voltage 5V and 24V fans do not rotate when PWM duty cycle is 0％.

That implies the 12v fans do rotate when PWM is 0%, makes no sense.

Yes I have seen that.  I will try next week with another type.