help with "USE_CONTROLLER_FAN"

Victor_SH

Hi
I am in a process of upgrading the stepper drivers to tmc2208
and wanted to use the USE_CONTROLLER_FAN option so the fan will only kick in when the motors are active
I tried to use the HE1 (#define CONTROLLER_FAN_PIN 7) on the board to run a fan
since i have a 12V fan I configured the  CONTROLLERFAN_SPEED 127
checked with multimeter that its actually 12V 
tried to connect a fan but the fan died

how can I solve this problem?
do I need to use only 24V fan on that output(HE1)?
can i use 5V fan with USE_CONTROLLER_FAN function on other pin if so on what pin?



Thanks

Samuel Pinches

welcome @Victor_SH !
Regarding mosfets and voltages, I think you'll find this is a related thread...
https://jgmakerforum.com/discussion/comment/2561

I don't think the voltage is 12V - it is a PWM controlled output which normally means 24v -> 0V -> 24V -> 0V repeatedly, very quickly. Normally capacitor is required if you want to smooth this output to 12V.

Victor_SH

According to the meter it's 12.5v
On the video now I see that at first second there is 18v reading 


But never mind I get 2 5v 0.35a fans
How I can connect them?
The 2 ports on the right side can accept 0.35a draw
If so can I control them with USE_CONTROLLER_FAN

Prokktor

I can help you half the way^^

The frequency of the pwm signal is usually between 5000 and 20000 Hz, so you can not possibly see that on an standard multimeter. You will need an oscilloscope.
(Theoretically you can use any pc with microphone jack but thats a whole other topic^^)
There are various ways you can get a 24v PWM to run a 12V Fan:
- a mosfet that is competible with pwm signals and a true 12 power supply
- a 24v 12v dc  dc converter
- run 2 fans in series (they must be identical)

But the easiest way is: Buy a cheap 24V fan^^

You can also look at my solution here:
https://jgmakerforum.com/discussion/414/project-upgrading-the-a5-to-direct-drive-full-metal-hotend-auto-bed-leveling-for-under-60#latest

Victor_SH

I have a 24v double bearing fan but it's 80x80 so I need to print adaptor for it

So no way to control the 5v pins on the board? 

Prokktor

Well you do have multiple Servo connectors, which have a signal pin, which in turn is pwm controlled 5V.
It may even have enough power for a small fan... but I am not 100% certain that works (its a 50Hz Servo signal as far as i know, not made to power anything)
And you will have to modify the firmware...

I do not really get your plan as a whole, just let the fan run all the time...
I printed the blue duct for my tcm fan and it will simply always run... getting a silent fan is much easier than everything mentioned here^^

Victor_SH

My plan is to make the pinter as silent as possible 
I want to use the controller fan option
To make the fan stop spinning when the print is done 
A lot of the time I leave the printer at night printing 
And when it's done the 5v fan is still spinning and make a lot of noise
This 5 volt fan they verry powerful at 0.35a 
Don't want to slow them down using resistors because the printer is in closed enclosure 
Same as prusa i3 ikea lack enclosure in thingiverse

Prokktor

Hmm ok if thats the goal:
Connect the printer to some wifi controlled power (I use broadlink sp3) which in turn is controlled by home assistant, that can read tons of different sensors.

Just turn the printer off 5 min after the print is done^^

Victor_SH

how to know when the printing is done? the print time calculation is not 100% true
probably I will just mount 24V fan to the HE1 output

stil in a process of  building the enclosure

Prokktor

That looks nice.

There are various ways to check if your printer is still working:

- it will use less power which is detectable with a wifi wall plug that measures ampere (maybe a sp3s?)
- it will be less noisy, which can also be measured
- you can install the wifi module for the mks gen l (probably?) or use octoprint to send a signal over wifi to the home assistant
- after the print it will move the y axis to the endstop, you can probably solder a second pair of wires to this endstop and use it to detect when the print is finished

Victor_SH

The use controller fan option is more simple
When the motors stop moving after a minute the fan stop spinning too 
And it start spinning only when the motors start moving

Prokktor

He explains what you need^^