Why molex fans exist

[data1]

Hi
I have couple case fans Id like to use for my setup but they both have molex connection. I wonder whats the point with that because if I connect them directly to PSU they run at full speed and make a lot of noise. What am i not getting here, whats the point in molex connection?

is there an adapter to these things?

thx

 

[mackerel]

Are they particularly old? Haven't seen any like that in the PC space in many years, possibly decade+. Presuming they're not going to have PWM you'd need something to drop the voltage to control the speed. There used to be a 7V mod people used to do, wiring the fan between the 12V and 5V lines, giving 7V difference thus running slower. You could do that by poking out the pins on the connector and moving them accordingly.

 

[data1]

Are they particularly old? Haven't seen any like that in the PC space in many years, possibly decade+. Presuming they're not going to have PWM you'd need something to drop the voltage to control the speed. There used to be a 7V mod people used to do, wiring the fan between the 12V and 5V lines, giving 7V difference thus running slower. You could do that by poking out the pins on the connector and moving them accordingly.

yeah they are pretty old. i dont think im enough tech-savvy to do such edits

 

[Blaylock]

They also make fan controllers which are just potentiometers that lower the voltage. If the noise is an issue, simply replace them. Otherwise runnem' til they die. Lol

 

[data1]

if I let the fan run at max speed the PC will turn to a drone XD

Anyways, I found another molex fan that actually has speed switch. So I'm going to use that

Still kinda curious about the molex history, did PC manufacturers put the voltage mod to some of the molex connections or what

 

[EarthDog]

if I let the fan run at max speed the PC will turn to a drone XD

Anyways, I found another molex fan that actually has speed switch. So I'm going to use that

Still kinda curious about the molex history, did PC manufacturers put the voltage mod to some of the molex connections or what

Some. Or you bought a controller or mod it.

These are old fans. Get new ones that us the more modern (and easily controlled by your mobo) fans.

15 y.o tech, meng.

I don't know why you'd want to use them, honestly.

 

[data1]

Some. Or you bought a controller or mod it.

These are old fans. Get new ones that us the more modern (and easily controlled by your mobo) fans.

15 y.o tech, meng.

I don't know why you'd want to use them, honestly.

The only reason i want to use them is because i put up together a PC from old parts (For fun). just to get rid of the parts and give it away . so Im on zero budget

 

[don256us]

"Back in the day", motherboards didn't have fan headers. The only way to connect them was to have a molex to connect to the power supply. Then came fan headers on motherboards but too many fans may draw too much power so a molex connector was still a good idea.

To control the fan speed, we used to pair the 12 and 5v legs together. 12+ground = 12v. 5+ground = 5v. 12+5 = 7v. If your fan worked at lower voltages, this was how we did it. I never lost a fan or device doing this but it can't be good. I'm NOT recommending that you do this.

In modern times, companies like Noctua include resisters with their fans. Resisters and manipulating the molex connectors were not easily changed. You basically set it and forget it. Especially with the 80mm fans which for a time was all that was available. They were LOUD! Swapping pins on a molex connector could really save your sanity.

So yeah. For a while, molex was the only way to power a fan in AT and early ATX systems.