| 摘要 |
PURPOSE:To enable the control of batch injection quantity with high accuracy, by providing a pulse oscillation circuit and making the oscillation frequency of said circuit variable. CONSTITUTION:A pulse signal S0 with predetermined frequency is outputted from a pulse oscillation circuit 1 and an electromagnetic pump member 3 is operated once per one pulse of said signal through a power photocoupler 2. A pulse counter 4 counts the number of pulses of the signal S0 and the count number N0 thereof is sent to a comparator 5. The desired number N1 of operations are preset to a setting switch 6 to be inputted to the comparator 5. When the count number N0 becomes equal to the number N1 of operations, the comparator 5 outputs a trigger signal S1. Because an H-level signal is inputted to the terminal D of D-FF 10, when the signal S1 is inputted to a terminal C, the value of an output terminal Q comes to an H-level to be held. The operation completion signal S2 from the terminal Q is inputted to the circuit 1 through an OR circuit 12 to stop the circuit 1. By this constitution, the member 31 is operated for the number of times corresponding to the number of operation times set by the switch 6 and a definite amount of a chemical liquid is accurately injected in an objective container.
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