| 摘要 |
PURPOSE:To make an electromagnetic driving current constant and to keep the precision, by connecting equivalent loads in parallel to two electromagnetic devices for shutter opening and closing which are connected in parallel to a power source and supplying the power to loads on a basis of exclusive OR of shutter opening/closing pulses. CONSTITUTION:Transistors (TR) Qo and Qc are made conductive during periods of widths of a shutter opening control pulse (op) and a shutter closing control pulse (cp) in accordance with the generation of these pulses to supply the power to coils Lo and Lc. Inverters I1 and I2, AND gates AG1 and AG2, and OR gate OR constitute an exclusive OR circuit, and the conduction of a TR Qa is controlled by the output of this circuit to control the power supply to a resistance R which is a load equivalent to respective coils. Thus, the driving current to each coil is changed in accordance with the overlap of control pulses. |
