Electrical power supply device comprising a first input terminal and a second input terminal between which an AC input voltage (Vin) may be applied, including: - a rectifier that is connected in series to the second input terminal; - an oscillator that is connected to the first input terminal and the rectifier, said oscillator including: - a DIAC-type diode (DIAC) that is connected both to a connection point connecting a first resistor to a first capacitor and to a second capacitor, said second capacitor being connected to a first downstream terminal; - a resistor that is connected between the connection point between the DIAC-type diode (DIAC) and the second capacitor and a second downstream terminal; - a voltage converter (CONV), which is connected to the first downstream terminal so as to be controlled by control pulses that are generated by said oscillator in order to generate electric current pulses and which is arranged to deliver a DC output voltage (Vout) on the basis of the voltage between the first input terminal and the rectifier by generating said electric current pulses; - the oscillator being arranged to deliver said control pulses, the amplitude of which is limited to below a voltage threshold value by the DIAC-type diode; - the first capacitor having a capacitance the value of which determines the number of control pulses on each alternation of the AC input voltage; - the second capacitor having a capacitance the value of which determines the duration of each generated control pulse. - a rectifier that is connected in series to the second input terminal; - an oscillator that is connected to the first input terminal and the rectifier, said oscillator including: - a DIAC-type diode (DIAC) that is connected both to a connection point connecting a first resistor to a first capacitor and to a second capacitor, said second capacitor being connected to a first downstream terminal; - a resistor that is connected between the connection point between the DIAC-type diode (DIAC) and the second capacitor and a second downstream terminal; - a DIAC-type diode (DIAC) that is connected both to a connection point connecting a first resistor to a first capacitor and to a second capacitor, said second capacitor being connected to a first downstream terminal; - a resistor that is connected between the connection point between the DIAC-type diode (DIAC) and the second capacitor and a second downstream terminal; - a voltage converter (CONV), which is connected to the first downstream terminal so as to be controlled by control pulses that are generated by said oscillator in order to generate electric current pulses and which is arranged to deliver a DC output voltage (Vout) on the basis of the voltage between the first input terminal and the rectifier by generating said electric current pulses; - the oscillator being arranged to deliver said control pulses, the amplitude of which is limited to below a voltage threshold value by the DIAC-type diode; - the first capacitor having a capacitance the value of which determines the number of control pulses on each alternation of the AC input voltage; - the second capacitor having a capacitance the value of which determines the duration of each generated control pulse.