2.1.8Alarm Circuit
(1)Head drive time alarm circuit
This circuit monitors the drive time using the HDALM signal interlocked with the overdrive signal of each drive circuit.
If the drive time of any drive circuit exceeds the specified time, the drive fault alarm circuit sends an
This cause the secondary coil (40V) of the transformer to be
(2)Alarm processing when DC power is low.
+ 40V is converted into the POWLEV signal (0V to +5V) by R28 and R29 and input into the A/D port of the MPU to control the drive time and the print speed (pass number) of the head.
+40V
R28
POWLEV
R29
(a)Head drive time
The head drive time is lengthened to compensate for the amount of voltage drop by monitoring the POWLEV signal once every 500 μ sec. to control and maintain the impact necessary for each printing pin at the fixed value.
(b)Print speed
Voltage, +40V | Pass number | Print speed |
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38V or more | 1 Pass | 100% |
25V to 37V | 1 Pass | 100~30% |
25V or less | 1 Pass | 30% |
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