A burner for a boiler or industrial applications, comprising: - a conduit for supply of the fuel; - a conduit for supply of a comburent; - a control system operatively connected to the conduits for supply of the fuel and the comburent for regulating a respective flow rate thereof; said control system having a housing for a sensor for detecting a flame; said control system being preconfigured for receiving in input at least a first range of voltage and/or current characteristic of a photo-resistance flame sensor and corresponding to a status of absence or loss of the flame and at least a second range of voltage and/or current characteristic of a photo-resistance flame sensor and different from the first and corresponding to a status of presence of the flame; - a sensor for detecting a flame configurable between a condition of disconnection from the control system and a condition of connection in which it is inserted in said housing and electrically connected to the input of the control system so as to send a flame signal from an interface electric circuit to the control system; said control system being configured so as to regulate the flow rate of fuel and/or comburent according to the levels of voltage and/or current received by said flame signal; wherein said sensor comprises: - a sensitive element of the flame comprising a phototransistor or photodiode in use facing the flame to receive an electromagnetic wave emitted by the flame; said sensitive element being configured for generating a detecting signal having voltage and/or current that is variable as a function of the electromagnetic wave emitted by the flame and corresponding at least to a status of absence of the flame or of presence of the flame; - said interface electric circuit being connected between the sensitive element and an output of the circuit configured for converting the detecting signal generated by the sensitive element into a flame signal characteristic of a photo-resistance flame sensor; said flame signal having a first voltage and/or current level that falls within the first range of voltage and/or current of the control system characteristic of a photo-resistance flame sensor, when the electromagnetic wave emitted by the flame corresponds to the status of absence or loss of the flame; said flame signal having a second level of voltage and/or current that falls within the second preset range of voltage and/or current of a photo-resistance flame sensor, when the electromagnetic wave emitted by the flame corresponds to the status of presence of the flame. - a conduit for supply of the fuel; - a conduit for supply of a comburent; - a control system operatively connected to the conduits for supply of the fuel and the comburent for regulating a respective flow rate thereof; said control system having a housing for a sensor for detecting a flame; said control system being preconfigured for receiving in input at least a first range of voltage and/or current characteristic of a photo-resistance flame sensor and corresponding to a status of absence or loss of the flame and at least a second range of voltage and/or current characteristic of a photo-resistance flame sensor and different from the first and corresponding to a status of presence of the flame; - a sensor for detecting a flame configurable between a condition of disconnection from the control system and a condition of connection in which it is inserted in said housing and electrically connected to the input of the control system so as to send a flame signal from an interface electric circuit to the control system; said control system being configured so as to regulate the flow rate of fuel and/or comburent according to the levels of voltage and/or current received by said flame signal; - a sensitive element of the flame comprising a phototransistor or photodiode in use facing the flame to receive an electromagnetic wave emitted by the flame; said sensitive element being configured for generating a detecting signal having voltage and/or current that is variable as a function of the electromagnetic wave emitted by the flame and corresponding at least to a status of absence of the flame or of presence of the flame; - said interface electric circuit being connected between the sensitive element and an output of the circuit configured for converting the detecting signal generated by the sensitive element into a flame signal characteristic of a photo-resistance flame sensor; said flame signal having a first voltage and/or current level that falls within the first range of voltage and/or current of the control system characteristic of a photo-resistance flame sensor, when the electromagnetic wave emitted by the flame corresponds to the status of absence or loss of the flame; said flame signal having a second level of voltage and/or current that falls within the second preset range of voltage and/or current of a photo-resistance flame sensor, when the electromagnetic wave emitted by the flame corresponds to the status of presence of the flame.