Connecting 2 12v fans

[L1ph70u]

The new thread you started is about testing the same fans you were connecting in your original thread so I've merged both threads into one to prevent confusion.

thank you for this
The curious thing is I recognized that 1 Fan is spinning on full speed and the other at 50%.
They are wired parallel and if I'm connecting 1 to 12v pins and 1 to 7v, they are running on the same speed. thats weird.

 

[DPG]

I'm out.

5 words.

 

[L1ph70u]

I'm out.

5 words.

? did I said something wrong?

 

[L1ph70u]

I'm out.

5 words.

I checked with a multimeter, there are 12.03 V
so it's a steady 12V Dc

 

[DPG]

? did I said something wrong?

Sorry, no offence intended. I don't think I can offer anything else.

Fans in parallel will receive the same voltage as each other. They will need to be connected to a source which will provide 12VDC at the necessary current. If they are not the same type then they may spin at different speeds. If the source is not capable of sourcing sufficient current, then when a second fan is added the supply may collapse.

 

[L1ph70u]

Sorry, no offence intended. I don't think I can offer anything else.

Fans in parallel will receive the same voltage as each other. They will need to be connected to a source which will provide 12VDC at the necessary current. If they are not the same type then they may spin at different speeds. If the source is not capable of sourcing sufficient current, then when a second fan is added the supply may collapse.

Yes I wrote that I checked it with a multimeter, there are steady 12.03V.
They are not the same type.
In my opinion its weird that they are spinning the same speed when I connect 1 to run on 7V and 1 Fan on 12V.
If I connect both to 12V (always Parallel) one fan spins at 50 % and one at 80%.
I already thought that this is caused by the different Fan Types.

The only question I want to ask was how I could Check the Voltage on each Fan because they are spinning different with 12V.
I know that they should get the same voltage but why they are spinning at different RPM with same voltage, does it belongs to the Ampere?

 

[dmxtothemax]

You stated that with one fan speed is correct, but with two it is not ?
Maybe the fan power source is current limited ? So it does NOT have the power to drive two fans. Only enough for one.
if you insist on two fans you need to find another source for your power.

 

[Bobster]

Have you tested the voltage with the fans running?

My guess is it's been specifically designed for 1 fan, and the extra current draw is dropping the voltage.

 

[Spoon]

I did mention the possibility of the limited current in post #22 and the connector has been designed for only 1 fan.

The OP may have gone down a different route now...

 

[pirate]

"I already thought that this is caused by the different Fan Types."

Is it now the case that the 2 fans are not the same type? " different fans with different characteristics maybe?