Light signal system having: - a circuit arrangement (41, 41a, 41b, 41c, 41d) for adjusting the brightness of signal transmitters (43a, 43b, 43c) of the light signal system, the circuit arrangement (41, 41a, 41b, 41c, 41d) having: - a voltage supply interface for receiving an electrical supply voltage (V supp), the light signal system further having: - a signal transmitter device, having the signal transmitters (43a, 43b, 43c), and - a signal transmitter switching unit which is connected between the circuit arrangement (41, 41a, 41b, 41c, 41d) and the signal transmitter device and is configured to switch over between different signal transmitters (43a, 43b, 43c) and to electrically connect the different signal transmitters (43a, 43b, 43c) to the circuit arrangement (41, 41a, 41b, 41c, 41d) or to electrically disconnect the different signal transmitters (43a, 43b, 43c) from the circuit arrangement (41, 41a, 41b, 41c, 41d), characterised in that - the circuit arrangement (41, 41a, 41b, 41c, 41d) further has: - a voltage conversion unit for generating a carrier signal as a direct current voltage signal by converting the electrical supply voltage (V supp) into a carrier signal voltage (V sig), - a control data receive unit for receiving a control signal, wherein the control signal comprises control commands in respect of a brightness that is to be set for the light signal system, - a modulation signal generation unit for generating a modulation signal as a function of the received control signal, and - a modulator unit (45, 8) for modulating the carrier signal by means of the modulation signal into a modulated control signal for controlling the brightness of the signal transmitters (43a, 43b, 43c), - wherein each signal transmitter (43a, 43b, 43c) has: - a demodulation unit which is configured to receive the modulated control signal from the circuit arrangement and to demodulate the same into the modulation signal and the carrier signal, and - a signal processor which is configured to set, on the basis of the control commands contained in the modulation signal, a current flowing through the signal transmitter or an electrical voltage present at the signal transmitter to a command-specified value. - a circuit arrangement (41, 41a, 41b, 41c, 41d) for adjusting the brightness of signal transmitters (43a, 43b, 43c) of the light signal system, the circuit arrangement (41, 41a, 41b, 41c, 41d) having: - a voltage supply interface for receiving an electrical supply voltage (V supp), - a voltage supply interface for receiving an electrical supply voltage (V supp), - a signal transmitter device, having the signal transmitters (43a, 43b, 43c), and - a signal transmitter switching unit which is connected between the circuit arrangement (41, 41a, 41b, 41c, 41d) and the signal transmitter device and is configured to switch over between different signal transmitters (43a, 43b, 43c) and to electrically connect the different signal transmitters (43a, 43b, 43c) to the circuit arrangement (41, 41a, 41b, 41c, 41d) or to electrically disconnect the different signal transmitters (43a, 43b, 43c) from the circuit arrangement (41, 41a, 41b, 41c, 41d), - the circuit arrangement (41, 41a, 41b, 41c, 41d) further has: - a voltage conversion unit for generating a carrier signal as a direct current voltage signal by converting the electrical supply voltage (V supp) into a carrier signal voltage (V sig), - a control data receive unit for receiving a control signal, wherein the control signal comprises control commands in respect of a brightness that is to be set for the light signal system, - a modulation signal generation unit for generating a modulation signal as a function of the received control signal, and - a modulator unit (45, 8) for modulating the carrier signal by means of the modulation signal into a modulated control signal for controlling the brightness of the signal transmitters (43a, 43b, 43c), - a voltage conversion unit for generating a carrier signal as a direct current voltage signal by converting the electrical supply voltage (V supp) into a carrier signal voltage (V sig), - a control data receive unit for receiving a control signal, wherein the control signal comprises control commands in respect of a brightness that is to be set for the light signal system, - a modulation signal generation unit for generating a modulation signal as a function of the received control signal, and - a modulator unit (45, 8) for modulating the carrier signal by means of the modulation signal into a modulated control signal for controlling the brightness of the signal transmitters (43a, 43b, 43c), - wherein each signal transmitter (43a, 43b, 43c) has: - a demodulation unit which is configured to receive the modulated control signal from the circuit arrangement and to demodulate the same into the modulation signal and the carrier signal, and - a signal processor which is configured to set, on the basis of the control commands contained in the modulation signal, a current flowing through the signal transmitter or an electrical voltage present at the signal transmitter to a command-specified value. - a demodulation unit which is configured to receive the modulated control signal from the circuit arrangement and to demodulate the same into the modulation signal and the carrier signal, and - a signal processor which is configured to set, on the basis of the control commands contained in the modulation signal, a current flowing through the signal transmitter or an electrical voltage present at the signal transmitter to a command-specified value.