Oki ML420 Maintenance Manual

Also see for ML420 Series: Specification sheet User guide User guide Installation Installation

Contents

Oki ML420 Maintenance Manual Manual pdf 23 page image

Oki Data CONFIDENTIAL42113931TH Rev.1 23 /2.1.8 Alarm Circuit(1) Head drive time alarm circuitThis circuit monitors the drive time using the DT1ALM1-N signal interlocked with theoverdrive signal of each drive circuit.If the drive time of any drive circuit exceeds the specified time, the drive fault alarm circuitsends an ALM-P signal to POWER SUPPLY UNIT.This signal turns off +40V and +5V output. This state is maintained after the power switchis turned off until the power supply resumes about 30 seconds later. Until the cause ofthe output of the ALM-P signal is removed, even if the power supply is resumed thisfunction operates so that no +40V and +5V output occurs.(2) Alarm processing when DC power is low.+40V is converted into the DC LOW-N signal (0V to about 3.3V) by resistors and inputinto the A/D port of the SOC to control the drive time and the print speed (pass number)of the head.(a) Head drive timeThe head drive time is lengthened to compensate for the amount of voltage bymonitoring the DC LOW-N signal and maintain the impact necessary for each printingpin at the fixed value.(b) Print speed(3) FAN alarmThe SOC detects 3.3V on the signal even through the fan is driven.3.3VR653R652 FANALM-PFANMOTORVoltage, +40V Pass number Print speed36V or more 1 Pass 100%Less than 36V 2 Pass 50%(4) Space motor drive alarm circuitThis circuit monitors the drive time and drive current using the SPMALM-P and SP_OVER_C-P signals interlocked with the overdrive signal of FET of Phase U, V and W.If the drive time of any drive circuit exceeds the specified time, or if the drive current morethan the specified current, the drive fault alarm circuit sends an ALM-P signal to POWERSUPPLY UNIT.This signal turns off +40V and +5V output. This state is maintained after the power switchis turned off until the power supply resumes about 30 seconds later. Until the cause ofthe output of the ALM-P signal is removed, even if the power supply is resumed thisfunction operates so that no +40V and +5V output occurs.