| 摘要 |
PURPOSE:To control an output voltage finely by controlling the ignition phase angle of a thyristor at a short pitch of a time unit obtained by dividing a timing pulse period finely. CONSTITUTION:When a zero-cross synchronizing signal ZPS is inputted from a signal generating circuit 2 to an arithmetic control circuit 1, a CPU executes a zero- cross interruption processing program PRGP1 from an ROM and then executes an arithmetic processing timer PRGP3 uninterruptedly. In this case, the CPU constitutes a time unit, obtained by diving the time of a timing pulse TPS period, by an arithmetic processing time and computes an ignition point of a TH5 by a signal from an output-value setting circuit 3, thereby starting the TPS when arithmetic constituting the time unit is performed as many times as required circuits according to the arithmetic result. Then, when the TPS is calculated as many times as required by a TPS interruption PRGP2, an ignition control pulse GPS4 is generated by the TH5. Consequently, a time t1 is controlled at a shorter time pitch than the TPS period to control the output voltage of the TH5 finely. |
