Why do computer fans have 3 wires?

The Answer. A three pin connector is basically power (5/12 volt), ground, and signal. The signal wire measures how fast the fan is moving without any controls for the fan's speed. With this type, fan speed is typically controlled by increasing or decreasing the voltage over the power wire.

How does a 3-wire cooling fan work?

In a 3-wire fan, first two wires are the power supply wires of the fan. The third wire, comes directly from the output of the built-in 'Hall Sensor' chip generates output pulses during the fan rotation. With the help of this third wire, a monitoring circuit can 'see' the rotation.

Can you run a 3-wire fan with 2 wires?

The 3 Pin fan will fit onto the 2 pin you just need to match the holes and the pins and see which two contacts make the fan function.

Will a 3 pin fan work in a 2 pin slot?

It's safe as long as the rated Amperage for both fans added doesn't exceed the max ouput of the header slot. For example if the header was 1A(1000mA) and each fan was 300mA (2x300mA=600mA) you're fine.

Can a computer fan run on 12v?

Yes red and black 12v would give you full speed.

[Eng] How to Run CPU fan on 12v battery | 3 wire to 2 wire Cooling fan Mod, Pinout, Reverse Polarity

Can you control fan speed with 3 pin?

The speed of BOTH 3-pin and 4-pin fans can be controlled, but the method is different for the two types. For 3-pin fans, the connections to it are Ground to Pin #1, +VDC (varying) to Pin #2, and Speed signal on Pin #3.

Are 3 pin fans PWM?

These fans are also called 3-pin fans, as they come with 3 pins: a supply pin (usually 12 V DC), a ground pin, and a signal pin. PWM fans are DC fans with an extra wire for PWM. PWM fans are 4-pin fans, where the fourth wire sends a PWM signal to the fan motor. The PWM signal is the control input of the PWM fan.

What is the difference between 3 and 4 pin fans?

The significant difference in practice is that 4-pin fans allow for RPM to change based on the need for cooling temperature, this reduces noise and power consumption. While 3-pin can control the voltage, but the voltage can't turn to change the fan RPM at all and accurate as much as 4 pin fans.

How long will a computer fan run on a 12v battery?

Your 30 watt fan will draw about 2.5 amps at 12 volts (2.5 times 12 is 30). Assuming 90% efficiency from the inverter means that the inverter will draw 2.5/. 9, or 2.78 amps. A 50 Ahr battery will last 50/2.78 or 18 hours.

What is the blue wire on a computer fan?

On certain fans (3 pin) the blue wire is the RPM sensor. On 4 pin fans the blue wire is PWM.

Why do my fans have 3 pins?

Two of them are for the CPU and three are for the case fans. 4-pin connectors offer the ability to control fan speed via pulse width modulation (PWM).

Can you use a 3 pin fan on a 4 pin connector?

A 3-pin case fan can easily be connected to a 4-pin connector on the motherboard. The fourth pin is simply left blank in this configuration. In most cases, it will then run unregulated at a fixed speed.

What happens if you set 3 pin fan to PWM?

PWM Mode only - the header puts out exactly the signals for a standard 4-pin fan system header and is using PWM Mode. This can provide power to both fan types, but it can NOT control the speed of a 3-pin fan - that fan will run full speed all the time.

Where do 3 pin fan connectors go?

As typical motherboard fan connector is a three or four-pin connector attached to the end of a PC fan's wire. This is attached to the three or four-pin fan header on the motherboard. There's no trick aside from lining up the notch on the connector with the guide on the header.

Should my PC fans be PWM or DC?

PWM fans will usually set you back more, but use less power and produce less noise. DC fans are likely just as effective and cheaper, but they will also be noisier. One thing to consider is the number of 4-pin connectors on your motherboard.

What are the 4 wires on a PC fan?

A 4-wire fan has power, ground, a tach output, and a PWM-drive input. PWM, in brief, uses the relative width of pulses in a train of on-off pulses to adjust the level of power applied to the motor. A 2-wire fan is controlled by adjusting either the dc voltage or pulse width in low-frequency PWM.

Can you run a PC fan with a battery?

Computer fans can be hooked up to a battery if the battery is of the correct voltage. Computer fans vary in size and voltage requirements. Some fans, such as the tower cooling fans, operate at 12 volts while Central Processing Unit (CPU) fans may operate at seven volts.

Can you Overvolt a PC fan?

Most fans are rated up to 13.8V, so you can overvolt safely-ish up to that voltage, or go further which will worsen lifespan exponentially. You should check the spec sheet for your fan which will show "Operation voltage", which is a higher maximum then the rated voltage.

How long will a 9V battery power a PC fan?

It will probably run at about 3/4 the speed and draw about 3/4 the current (rough estimate) so around 100mA. Looking at a typical datasheet for an alkaline 9V battery, we can see the capacity will be perhaps 350mAh (down to 4.8V) so it might work for 3-5 hours, as the current will drop as the battery discharges.

Why are some fans 3 pin and some 4 pin?

The three wire connectors are for small chassis fans with lower power consumption. The four wire connectors are for processor fans with higher power consumption.

Why does my PC fan have 2 plugs?

Some fans may come with both a 4-pin and a 3-pin “female” connector which you can plug onto the headers that control the motor of your fan. The 4-pin should be plugged in the slot with PWM Mode on while the 3-pin connects to any other fan header ( e.g. SYS_FAN).