Abstract: Various embodiments include a control system comprising: an ionization electrode; a flame sensor; a first signal conditioning circuit for the ionization electrode; a second signal conditioning circuit for the flame sensor; an output unit; and a processor. The processor: receives a first and a second ionization signal indicative of ionization currents from the first signal conditioning circuit; receives a first and a second flame signal indicative of radiations originating from a flame via the second signal conditioning circuit; produces a derived ionization signal as a function of the first and the second ionization signals; produces a derived flame signal as a function of the first and the second flame signals; determines if a flame lift-off condition exists based on the derived ionization signal and the derived flame signal; and if a flame lift-off condition exists, produces a safety signal and transmits the safety signal to the output unit.

Abstract: Various embodiments include a control system comprising: an ionization electrode; a flame sensor; a first signal conditioning circuit for the ionization electrode; a second signal conditioning circuit for the flame sensor; an output unit; and a processor. The processor: receives a first and a second ionization signal indicative of ionization currents from the first signal conditioning circuit; receives a first and a second flame signal indicative of radiations originating from a flame via the second signal conditioning circuit; produces a derived ionization signal as a function of the first and the second ionization signals; produces a derived flame signal as a function of the first and the second flame signals; determines if a flame lift-off condition exists based on the derived ionization signal and the derived flame signal; and if a flame lift-off condition exists, produces a safety signal and transmits the safety signal to the output unit.

Abstract: A safety device includes a monitoring unit, a test block and an output stage having at least one contact member. The monitoring unit includes at least two outputs and provides at least two, different output signals for testing its absence from faults. The monitoring unit provides at least one enabling signal for a switch-off function The test block includes at least one input and is configured to monitor at least one of the output signals of the monitoring unit. The test block also includes at least one output and provides at least one enabling signal for a switch-off function. The at least one contact member of the output stage has at least two inputs and is configured to link at least one of the output signals of the monitoring unit to the at least one enabling signal of the test block.

Abstract: A safety device includes a monitoring unit, a test block and an output stage having at least one contact member. The monitoring unit includes at least two outputs and provides at least two, different output signals for testing its absence from faults. The monitoring unit provides at least one enabling signal for a switch-off function The test block includes at least one input and is configured to monitor at least one of the output signals of the monitoring unit. The test block also includes at least one output and provides at least one enabling signal for a switch-off function. The at least one contact member of the output stage has at least two inputs and is configured to link at least one of the output signals of the monitoring unit to the at least one enabling signal of the test block.

Abstract: A capacitor connected to a voltage source is charged during a charging phase up to a voltage value, and during a discharging phase the capacitor is discharged via a coupling element connected to the flame sensor. The period for the charging or discharging phase of the capacitor respectively is selected in this case as a function of the characteristics of the flame sensor, especially of its impedance. For flame monitoring the charging and discharging of the capacitor is repeated cyclically, with the voltage signal obtained in this way being evaluated in single-channel mode with the aid of a threshold value.

Abstract: A capacitor connected to a voltage source is charged during a charging phase up to a voltage value, and during a discharging phase the capacitor is discharged via a coupling element connected to the flame sensor. The period for the charging or discharging phase of the capacitor respectively is selected in this case as a function of the characteristics of the flame sensor, especially of its impedance. For flame monitoring the charging and discharging of the capacitor is repeated cyclically, with the voltage signal obtained in this way being evaluated in single-channel mode with the aid of a threshold value.

Abstract: A circuit (1) for monitoring the state—open or closed—of an ac switch (2) has an input (4) which is connected by way of a diode (9) and a first resistor (10) to a high-ohmic input (11) of a first digital component (12). One terminal of the ac switch (2) is connected to the phase (P) of a mains voltage (UPN), while the other terminal is connected to the input (4) of the circuit (1). The high-ohmic input (11) of the first digital component (12) is connected by way of a second resistor (13) to an output (14) of a second digital component (15). In accordance with a predetermined time lapse, the output (14) of the second digital component (15) is either connected to the neutral point (N) of the mains voltage (UPN) or carries a voltage which is greater than the threshold voltage (US) of the input (11) of the first digital component (12).