| 摘要 |
<p>PURPOSE:To control a step advance smoothly by a method wherein a notch is advanced synchronously with a thyristor conduction control period, and an output of a phase step thyristor and an output of an on/off step thyristor are changed simultaneously by changing the stpe number. CONSTITUTION:A reference pulse 10a is outputted synchronously with a reference signal 2a synchronized with a thyristor conduction control period, and when a step advance command 11a is issued from a step advance commander 11, a step advance pulse generator 12 outputs a step advance pulse 12a synchronously with the reference pulse 10a, which is inputted to a counter 13. Counting the step advance pulse, the counter 13 outputs a step signal 13a in digital value, which is inputted concurrently to a phase angle signal generator 14 and an on/off signal generator 15. Then, a given phase angle signal 14a is outputted to a gate circuit GC1 from the phase angle signal generator 14, and on/off signals 15a, 15b for controlling on/off step thyristor are outputted to gate circuits GC2, GC3 from the on/off signal generator 15.</p> |
