24v Fan on a 12v system-Duet 2 Wifi
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I have a bunch of 24v fans that I want to use as a part cooling fan.
I tried using a buck converter to step up the voltage but it would not work. when I connect the converter alone to the 12v pwm, I can measure 24V out. but when I connect the fan, that drops to 1.8v. Is it even possible to do this in any way? -
Probably just a naming issue but a 'buck' converter will only reduce the voltage from the input voltage. A 'boost' converter will boost it.
Neither one of these devices are useful for PWM input - they need a solid input and produce a solid output.
There have been other discussions on this in this forum and I 'believe' the magic is in connecting the input of a boost converter to 12V then connect the +24V to the fan and connect the ground of the fan to the control pin on the duet.
As an aside, the duet outputs do not go high to switch an output on but the negative pin goes to ground instead (as opposed to floating when the output is off).This is off the top of my head .... do your own research in case something goes pear shaped .....
Maybe somebody else will chime in. -
@jens55
Thanks, I'll dig around and rewire to try that. -
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I always keep some of these boost converters handy for this sort of thing: https://www.amazon.com/Pieces-Converter-Adjustable-Voltage-Regulator/dp/B089Y7NDCR/ref=sr_1_4?dchild=1&keywords=boost+converter&qid=1615772659&sr=8-4
Not sure if they would be happy with a high frequency PWM input, but if you turned the PWM frequency down to maybe 10 Hz or so they'd probably be OK powering a print cooling fan.
There are similar size/price buck converters for dropping voltages, too.
https://www.amazon.com/MP1584EN-DC-DC-Converter-Adjustable-Module/dp/B01MQGMOKI/ref=sr_1_5?dchild=1&keywords=buck+converter&qid=1615772904&sr=8-5All of these are so cheap and so useful, it's worth buying some just to keep in your parts bin in case you need one some day. You never know when you'll need to light up an LED, power a fan, etc.
