8. OPERATIONAL NOTES
8.1 Power ON/OFF Note
If the 5 V power supply line for logic has not fully risen or fallen immediately after the power supply is turned ON or OFF, the CPU or TTL in the logic circuit may misoperate. At such times, power is supplied to the motor or solenoid, causing, in the worst case, burnt out solenoid or running of motor (misoperation), unless the 24 V power supply line for motor drive is completely OFF. To avoid such misoperation, take into account the following points.
8.1.1 Power supply ON/OFF timing rule
Supply 24 V line after the 5 V line has fully risen. Similarly, cut off the 5 V line after the 24 V line has fully fallen.
Fig. 8-1 Power supply ON/OFF timing rule
8.1.2 Method of controlling the drive circuit
Fig. 8-2 Drive circuit controlling method
If the power supply ON/OFF timing rule cannot be followed, reset the print solenoid or motor drive circuit with control signal. An example of this type of circuit is shown in Fig. 8-3. Turn OFF transistor TR1, while the 5 V line has not completely risen, in order to inhibit power to the print solenoid. Then as soon as the 5 V line has completely risen, turn ON TR1, permitting power to the print solenoid.
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