What are Molex Connectors

What is a Molex connector?

There are several types of connectors on a computer that are used to wire certain components such as hard drives, drives, or case fans. The connection to hard disks and optical drives, for example, is now usually established via SATA connectors.

Another type of connector in the computer field are the Molex connectors. Molex connectors offer complete connection solutions for different areas.

Molex connectors have a maximum voltage of 12 volts, which can be throttled by the Molex connector with a resistor. A throttling of the voltage is necessary for certain components that require less power than 12 volts or are to be operated with less voltage (e.g. fans).

Applications of Molex connectors

The areas of application of Molex connectors are diverse. They are used for case fans, LED tubes or other accessory components that require a maximum voltage of 12 volts. Components that can be used as hardware by the motherboard are usually not supplied with power with Molex connectors.

Case fan as an example

Case fans that are supplied with power via this plug connection can have a diameter of 4 cm to 18 cm. These fans convey air into the housing or convey warm air out of the housing, thereby cooling the components in the housing.

They are distributed on the case, on CPU coolers, on graphics card coolers and at various positions in the case. In the case itself, case fans can be attached to the front, back, top, bottom and on the sides.

However, the installation options depend on the type of housing. Cases for high-performance computers offer more options for installing fans than cases for less-powerful computers, since these do not develop as high temperatures as components of very high-performance computers.

Resistors can be used to regulate the fan speed, which can reduce the voltage from 12 volts to 5 volts. Alternatively, potentiometers can also be used, which enable the fans to be continuously regulated. Nowadays some fans are connected directly to the motherboard, which has several Molex connections for this purpose.

It is possible to use the fan with temperature control on the motherboard itself. This allows the fans to spin more slowly at low temperatures than at high temperatures.

Allocation of Molex connectors

Molex plugs have a minus and a plus pool and a pool for grounding. With some plugs, however, there is an additional cable that enables pulse modulation. In this way, for example, pulses can be sent to a fan at short intervals so that it rotates at a certain speed.

Pulse width modulation in fans is also known as PWN. Fans with PWN function are equipped with Molex connectors, which have an assignment of 4 cables. Fans without PWN function, on the other hand, have plugs that only have three cables.