Safety valve supply circuit for the ignition of a gas burner

A safety valve supply circuit for the ignition of a gas burner, said safety valve being directly supplied by a flame-detecting thermocouple, said supply circuit comprising a supply capacitor that is charged from an alternating mains voltage, obtaining from the energy accumulated in said supply capacitor, due to said charging, an input voltage signal that is used to temporarily supply said safety valve in order to maintain it open, said charging of the supply capacitor being carried out by momentarily activating a supply switch to temporarily connect the supply capacitor to said alternating mains voltage, said supply switch activation occurring concurrently with the activation of the gas burner, and said supply circuit also comprising conditioning means for converting said input voltage signal into an output voltage signal that is directly applied to said safety valve to supply it, and so maintain it open, the conditioning means comprising a transformer, the input voltage signal being the input signal of said transformer and the output voltage signal being obtained from the output signal of said transformer, and said supply circuit comprising control means with a control switch disposed in series with said transformer, said control means generating an operating signal that can open said control switch to prevent a forward current from circulating through the primary of said transformer during determined time intervals as the charge of the supply capacitor decreases, so that, by means of said opening, said control means can control the value of the output voltage signal, in order to supply the safety valve a substantially constant energy.