A single rail control system with receiver modules associated with a motherboard of a personal computer and a power supply, comprises a transmitter module, a connector module, and at least one receiver module. One of the first microcontrollers of the transmitter module is controlled by the motherboard or software running on the system/CPU. The connector module is associated with the transmitter module, the power supply, and the receiver module. The connector module is able to be connected in series to increase the number of the receiver module. The receiver module is able to simultaneously receive the control instruction of the first microcontroller and the power provided from the power supply through the connector module, so that a plurality of RGB LEDs are controlled by one of the second microcontrollers of the receiver module to emit light to the outside. Since the receiver module does not require additional power cables, the unnecessary wires can be effectively reduced.