an electrical oscillator having a piezoelectric resonator , the shift in frequency of which is automatically compensed when the oscillator is subjected to an acceleration . consequently , the oscillator is practically insensitive to high accelerations and can be used as a frequency standard in an aircraft or space vehicle . said oscillator comprises , in an oscillator loop , the resonator and a capacitance for adjusting frequency connected in series with the resonator . the adjusting capacitance is formed of at least one variable capacitor . means sensitive to acceleration are provided for controlling the variable capacitor so that the frequency shift caused by the variable capacitor is opposed to the frequency shift of the resonator caused by acceleration .