A system, comprising: a first device (110, 210, 310) including a first set of contacts; a second device (130, 230. 330, 380) including a second set of contacts, the second set of contacts adapted to electronically engage with the first set of contacts of the first device (110, 210, 310) to form at least a power and ground lines connection; each of the first device (110, 210, 310) and the second device (130, 230. 330, 380) including circuitry for providing data over the power line connection between the first device (110, 210, 310) and the second device (130, 230. 330, 380), the circuitry comprising: a power line; a ground line; a transmitter line carrying data signals; a first capacitor coupling the transmitter line to the power line at a connection point, the capacitor configured to filter DC components from the data signals and output a filtered signal that is carried to the power line; and characterised by a receiver comprising two field effect transistors (661, 662), the two field effect transistors (661, 662) configured to detect the filtered signal, wherein a first of the two field effect transistors (661, 662) is connected to the power line via a first reception line and a second of the two field effect transistors (661, 662) is connected to the power line via a second reception line; and wherein a second capacitor couples the first reception line and the first field effect transistor and a third capacitor couples the second reception line and the second field effect transistor. a first device (110, 210, 310) including a first set of contacts; a second device (130, 230. 330, 380) including a second set of contacts, the second set of contacts adapted to electronically engage with the first set of contacts of the first device (110, 210, 310) to form at least a power and ground lines connection; each of the first device (110, 210, 310) and the second device (130, 230. 330, 380) including circuitry for providing data over the power line connection between the first device (110, 210, 310) and the second device (130, 230. 330, 380), the circuitry comprising: a power line; a ground line; a transmitter line carrying data signals; a first capacitor coupling the transmitter line to the power line at a connection point, the capacitor configured to filter DC components from the data signals and output a filtered signal that is carried to the power line; and characterised by a receiver comprising two field effect transistors (661, 662), the two field effect transistors (661, 662) configured to detect the filtered signal, wherein a first of the two field effect transistors (661, 662) is connected to the power line via a first reception line and a second of the two field effect transistors (661, 662) is connected to the power line via a second reception line; and wherein a second capacitor couples the first reception line and the first field effect transistor and a third capacitor couples the second reception line and the second field effect transistor. a power line; a ground line; a transmitter line carrying data signals; a first capacitor coupling the transmitter line to the power line at a connection point, the capacitor configured to filter DC components from the data signals and output a filtered signal that is carried to the power line; and characterised by a receiver comprising two field effect transistors (661, 662), the two field effect transistors (661, 662) configured to detect the filtered signal, wherein a first of the two field effect transistors (661, 662) is connected to the power line via a first reception line and a second of the two field effect transistors (661, 662) is connected to the power line via a second reception line; and wherein a second capacitor couples the first reception line and the first field effect transistor and a third capacitor couples the second reception line and the second field effect transistor.