2 results about "Variable-frequency oscillator" patented technology

A spread spectrum switching power conversion circuit, a clock generation circuit and a clock generation method. The spread spectrum switching power conversion circuit includes: a power stage circuit including an inductor and a power switch for switching the power switch to perform power conversion according to a switching signal with spread spectrum; a variable frequency oscillator for generating a spread spectrum clock signal according to a spread spectrum control signal; a spread spectrum control circuit for generating the spread spectrum control signal according to a first clock signal and a second clock signal; and a pulse width modulation circuit for generating the switching signal according to a feedback signal based on the spread spectrum clock signal; wherein the spread spectrum control circuit samples and operates a first periodic waveform with periodicity and a first random waveform with randomness to generate the spread spectrum control signal. The first random waveform is generated according to the first clock signal, and the first periodic waveform is generated according to the second clock signal.

A control device for an AC excitation generator motor comprises a phase difference calculator (202) that outputs a slip excitation phase obtained by comparison of an armature winding phase and a rotor phase of an AC excitation generator motor, a variable frequency oscillator (209) that outputs a synchronous excitation phase as a frequency command value of a synchronous excitation frequency, output switches (201a, 201b) that select and output the slip excitation phase or the synchronous excitation phase in accordance with an excitation selection signal, a command value holder (323) that, when the synchronous excitation phase is selected, holds a horizontal axis current command at a horizontal axis current command value (Iqrf_0) at the time of switching from the slip excitation phase to the synchronous excitation phase, and a slip excitation frequency calculator (203) that calculates a slip excitation frequency of the slip excitation phase, wherein: a stabilization gain (213) is provided, and by means of said stabilization gain (213), a horizontal axis current command stabilization correction value (Iq_stb) is calculated using the result of comparing the synchronous excitation and slip excitation frequencies as input; and the horizontal axis current command stabilization correction value (Iq_stb) is biased to the horizontal axis current command value (Iqrf_0).