DC fan controller modification

[t1muk4s]

Hello!
I have a problem with a fan controller. The controller is able to regulate the voltage to the fan from 7 to 15 volts DC (speed regulation).
Also the controller is switching the voltage in the output from one output to the other so that the fan is able to spin in both directions (it switches the negative part of the output).
The fan has three wires so i assume that it has two coils.
I need to connect more fans to the controller, but the controller is only able to control 50W of fans. My goal is to boost somehow it to 300 or more watts.
I added a simple sketch to show the system.
What kind of solution is for this problem (so that the speed regulation works with the new switch block)?
Best wishes,
T.

 

[ronsimpson]

Please send more information on the fans. Part number?
Please send more information on the fan controller. Part number?

 

[t1muk4s]

Hello!

The fans are 3W and have two coils so three wires go to the fan. The controller works on 20V and gives out 5 - 17V for the fan.

 

[Reloadron]

Would these fans by any chance be everyday home computer type cooling fans? Everyday standard 12 volt fans with three wires, usually a red (+), black (-) and a third white or sometimes yellow wire which is actually a tach signal out of the fan. If this is what you have they are not likely reversible fans.

Ron

 

[t1muk4s]

No, these fans are not computer fans. The rotation is controled by switching the voltage between the wires.

 

[Reloadron]

Given a choice I would likely use PWM to control the speed through a logic level MOSFET as that should handle several fans and as to reversing direction I would use small relays or just use PWM driving an H Bridge for speed and reversing if that is what you want.

Ron