| 摘要 |
PROBLEM TO BE SOLVED: To make the switching timing synchronized with the period of the a-c component in a rectified a-c current for each power feed time set to an integral multiple of the period of the a-c component. SOLUTION: This power source generates pulse signals, synchronized with the period of an a-c current not yet rectified from a period detector circuit 10 and changes the address designated to a memory circuit 22 each time the no. of the generated pulse signals agrees with a time-designated signal obtd. from the memory circuit 22 so as to have an operation signal from this circuit 22 output to an output synchronous circuit 24 which feeds a control signal synchronized with the pulse signal to a switching circuit 16, based on the pulse signal and operation signal, thereby feeding an exciting current to an excitation coil 18 from the switching circuit 16. Thus each feed time to the coil 18 is at an integral multiple of the period of the a-c component in a d-c current after rectification, and the switching time in the feeding direction is synchronized with the a-c component period. |
