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Thread ID: 145850 2018-02-10 06:41:00 running 12v fan on AC tweak'e (69) Press F1
Post ID Timestamp Content User
1446144 2018-02-10 06:41:00 thought this might appeal.
just working on a project today and needed some fans to provide air flow for my air compressor cooler.
of course i found 4 case fans....... then another two fans. so 6 fans it is.
and just now i found another two fans :waughh:

but do you think i could find a spare 12v power pack.
but according to a certain someone who puts *ick in a vice, a lot of dc motors are universal motors, well thats what i remember from utube.
so dug out an old 9v AC pack.
what do you know it actually runs, and runs six of them at 8.5 volt.
however they are a tad slow so will be looking for a proper 12v DC supply.
tweak'e (69)
1446145 2018-02-11 20:29:00 alot of DC motor will run backwards on reverse polarity, so totally unsuited to AC

Not something I'd recommend in general. :-)
1101 (13337)
1446146 2018-02-12 09:33:00 found an old 12v 4a dc supply for some other computer thingy i have long since forgotten about.
so used that instead. big increase in speed.
actually i don't think the 9v was slowing it down rather it stayed at fixed speed due to the 50hz.
all the fans where doing about the same airflow on ac but now on dc the air flows are different.
also i do hear that the ac gives the brushes a hard time, so its probably best to run them on dc.

so now my compressor sounds like a swarm of angry wasps.
tweak'e (69)
1446147 2018-02-13 02:41:00 I use an old router power supply to run some fans, they tend to be 12V.
I'm surprised they worked on AC, would not have expected that.
dugimodo (138)
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