[FR] Ability to set PWM value for temp controlled output #153

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opened 2018-06-18 20:26:59 +01:00 by bumbalu · 4 comments
bumbalu commented 2018-06-18 20:26:59 +01:00 (Migrated from github.com)

Hello, Vitor.
Not always you have fan with exact sucking power you need. Sometimes your fan or heater has excessive power and you need to downregulate it. The fan should work at let's say 80% but in on-off mode, temp controlled. And you should be able to set its target temp during print.

I would like to have additional field to set the PWM for temperature controlled cooler.
The PWM-controlled output is not a solution because you can not change the target temperatures during print.

Thank you!

Hello, Vitor. Not always you have fan with exact sucking power you need. Sometimes your fan or heater has excessive power and you need to downregulate it. The fan should work at let's say 80% but in on-off mode, temp controlled. And you should be able to set its target temp during print. I would like to have additional field to set the PWM for temperature controlled cooler. The PWM-controlled output is not a solution because you can not change the target temperatures during print. Thank you!
vitormhenrique commented 2018-06-18 21:00:16 +01:00 (Migrated from github.com)

This was considered as discussed a few times here, but not really useful in my opinion, the enclosure of your printer is considerably larger than any heater and cooler, the time that it takes to change temperature turning it on and off it's on the order of magnitude of a bunch of seconds to minutes, this is called residence time. Temperature controlling it on a full on and off system is more than enough. It's used on the industry all the time (I'm a chemical engineer) if a reactor can be controlled like this I feel like an overkill to create more and more configurations on the plugin just to drive people nuts whiteout much gain for most of users... Trust me I get enough questions already...
Unless you have a full air conditioner unit inside your enclosure, or a hugeeeeee fan I really think it's an overkill... especially because most people use relays to control stuff, and you can not use relays with PWM outputs.
Never the less you can dial the power of whatever you are using down by decreasing the current to if, use lower voltage for a fan / heater for example.
I'm not saying that I'll not add this, but it's definitely on the lower queue of my priorities....

This was considered as discussed a few times here, but not really useful in my opinion, the enclosure of your printer is considerably larger than any heater and cooler, the time that it takes to change temperature turning it on and off it's on the order of magnitude of a bunch of seconds to minutes, this is called residence time. Temperature controlling it on a full on and off system is more than enough. It's used on the industry all the time (I'm a chemical engineer) if a reactor can be controlled like this I feel like an overkill to create more and more configurations on the plugin just to drive people nuts whiteout much gain for most of users... Trust me I get enough questions already... Unless you have a full air conditioner unit inside your enclosure, or a hugeeeeee fan I really think it's an overkill... especially because most people use relays to control stuff, and you can not use relays with PWM outputs. Never the less you can dial the power of whatever you are using down by decreasing the current to if, use lower voltage for a fan / heater for example. I'm not saying that I'll not add this, but it's definitely on the lower queue of my priorities....
vitormhenrique commented 2018-06-18 21:22:41 +01:00 (Migrated from github.com)

Just another comment on this feature: if and when I implement it, it will not be by setting pwm values, ti will use PID control and automatically calculate the output "power" based on the error of the set temperature and the current temperature.
You will be able to set the values for kp, ki and kd....

Just another comment on this feature: if and when I implement it, it will not be by setting pwm values, ti will use PID control and automatically calculate the output "power" based on the error of the set temperature and the current temperature. You will be able to set the values for kp, ki and kd....
bumbalu commented 2018-06-18 22:03:11 +01:00 (Migrated from github.com)

Ok, thank you, Vitor. My problem is a "huuge fan" as you said so I will limit its voltage.

Ok, thank you, Vitor. My problem is a "huuge fan" as you said so I will limit its voltage.
vitormhenrique commented 2018-06-18 22:04:54 +01:00 (Migrated from github.com)

for now do that, PID control will also solve your issue, just need to tune the constants...

for now do that, PID control will also solve your issue, just need to tune the constants...
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Reference: Gandalf/OctoPrint-Enclosure#153