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Patent Searching and Data


Title:
BACK-UP PROTECTING DEVICE FOR OPERATION TERMINAL
Document Type and Number:
Japanese Patent JPS5943401
Kind Code:
A
Abstract:
PURPOSE:To eliminate the need for the operation of a control station after power source recovery and to obtain a device with unity by allowing the output of an analog holding device to track an analog signal held in a control system at the timing after the power source recovery. CONSTITUTION:The output of the analog holding device is allowed to track the analog signal held in the control system at the timing after the power source recovery. For example, the output of the analog holding device 1 of a back- up holding part 8 is allowed to track the analog signal held in the control system 7 after the power source recovery. Then when the deviation between the outputs of the analog holding device 1 and control systems 7 decreases below the specific value of a deviation monitor 14, the deviation monitor 14 outputs 0 and an off-delay timer 17 carries on the tracking for a tracking time long enough to eliminate the deviation between both. When the off-delay timer 17 outputs 0, the tracking by the analog holding device 1 is stopped and analog holding operation is carried out to release the locking of an operation terminal by a solenoid valve 5.

Inventors:
KUMAZAKI MASAYUKI
Application Number:
JP15392082A
Publication Date:
March 10, 1984
Filing Date:
September 06, 1982
Export Citation:
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Assignee:
HITACHI LTD
HITACHI ENG CO LTD
International Classes:
G05B9/02; (IPC1-7): G05B9/02
Attorney, Agent or Firm:
Akio Takahashi