PWM Output 4-20mA
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Is there any pwm outputs 4-20mA that i can use to control a phase angle controller to control IR strip lamps on the delta printer i am modifying ? The temperature control will be via a thermocouple.
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You will need a PWM to 4-20mA converter for that. We designed and prototyped one for an OEM some time ago. I'll check whether we are allowed to publish the design.
Duet WiFi hardware designer and firmware engineer
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@dc42 Thanks, if it cannot be published, is there anyway around it i have a phase angle controller from RS 232-9353
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this thins?
https://docs.rs-online.com/0e21/0900766b8002e5be.pdfsays it can be current and voltage controlled, so you might be able to use a 5v pwm output and just smooth it if need be.
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@bearer How would i do this, i have limited experience in electronics?
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That is analogue electronics, or voodoo as its also called .. but I recon a RC filter set to a frequency well below the pwm frequency should work if the controller
draw powerdoesn't draw power from the 4-20mA loop.Just ask google or youtube for a "RC low pass fileter" and see if you have any components that will work. For something like this it hardly matters if the cutoff is 10, 100 or 1000hz as you can set the pwm frequency on the duet to match whatever components you may have on hand.
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Spoken to supply of the Phase angle controller and 0 to 5V PWM input is capable. What pins can i use on the duet to give this output and how would it be coded?
