Abstract: A voltage presence determination system intended to be connected to a voltage measurement sensor for at least one phase of a high-voltage electrical network. The system comprises, for the at least one phase: a visual indicator of the presence of a voltage measured by the voltage measurement sensor, referred to as the measured voltage, a first output terminal configured to receive a first output signal, a second output terminal configured to receive a second output signal, and a plurality of linear components. The system is configured so that the first and second output terminals are functionally isolated from one another and functionally isolated from the visual indicator only by the plurality of linear components.