Jump to content

One for Gina and other electronics gurus ???

Recommended Posts

I want to install a couple of 80mm computer cooling fans in my observatory to run 24/7 to extract air and provide a sustained throughput of airflow. I have a 12v DC supply handy.

All the ones I can find are either three wire or four wire.

Rather than try to figure out by trial and error (and possibly damaging the fans) which wire does what I thought I would ask the collective wisdom if its even possible to run a three wire fan with just pos and neg 12v supply ???

Something like this... https://www.amazon.co.uk/dp/B0119SLG18/ref=emc_b_5_t 


  • Like 1
Link to comment
Share on other sites

Yes :-)

Easiest option is to go for  3 pin and just use the + and -ve pins. The other pin a feed back of the fans actual speed, used by a speed controller.

I installed a PC fan on the back of my 200PDS with a PC fan speed controller and works a treat

Link to comment
Share on other sites

I have a similar system on the greenhouse, I run the extract fan slower than the input fan.

The very marginal increase in air pressure, that is probably only a few millibar has a noticeable effect on the volume of greenfly. Dependent upon how well sealed the obsy is, it may keep help the midges out. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...