| 摘要 |
PURPOSE:To automatically limit the applied voltage to an exposure lamp at always below constant voltage by shaping the waveform of the output voltage of a spurious load circuit by a limiting circuit and limiting the output of a comparator. CONSTITUTION:If there is an error between the output voltage of a waveform shaping circuit 34 and the reference voltage from a reference voltage generating circuit 39, the output voltage of an error amplifier 37 increases or decreases in accordance with the size of said error, and in accordance with this, the generating phase of the trigger pulse outputted from a trigger pulse generating circuit 41 changes as well. Hence, the conduction angle of a thyristor 32 changes and this change is fed back to the amplifier 37 by a trigger pulses to a dummy load circuit 33. |
