Using a rotary switch for controlling fan speed

This is my adapted version of what was at http://www.pcsilencioso.com/cpemma/sdiodes.html
Basically a rotary switch is used to select the how many diodes type 1N4001 are used to control the fans speed and a little circuit that is used to do a bar graph with the LEDs.

http://www.instructables.com/id/Using-Diodes-for-Fan-Control/

Category:

Science & Technology

Tags:

• electronics
• gadget
• computer
• diy
• LED
• switch
• fan
• controller

[TheLASERJAW]

Just use a cheap dimmer, put a rectifier inline for dc and save some money and have a fully variable fan speed.

[rek636]

@TheLASERJAW You could use a dimmer, but it would have to be one for 12v DC. A potentiometer would work also. Also doing this is actually fairly cheap. looking at $2-3 for the rotary switch and the diodes per fan.

[GT5Enthusiast]

Doesnt something like this only work if the fan has that many speeds? Or is this really controlling the flow of electricity through the fan. My fan controller on my 600t only works if the fan already has variable speeds.

[rek636]

@GT5Enthusiast it is actually just regulating the voltage that is going to the fan. Check out the links in the description to see how this works. This can also work on fans that already have a variable speed setting in them.

[TheLASERJAW]

Yes. Very good. Good job. Have a good day. :)

73 de N0RJP

[Wazoo117]

That's awesome wish I had one :P

[shuffle953]

@g5t8v6 because more speed more noise less speed less noise and people use fan controllers in different ways for example take an antec 300 case 2x front fans 1x top fan 1x back fan 1x side fan u get a 5 speed fan controller and lets say u want more cold air inside ur case so u turn up all the fans that are taking in air and then want more heat out of the case turn up the fans sucking out hot air i have heaps more reasons but they are the basic ones :D

[g5t8v6]

I wonder why you would want to control the fan speed. You really want its maximum power to suck out heat from the pc won't you? So why built a switch for it?