Title:
POSITIONER
Document Type and Number:
Japanese Patent JP2016156392
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To prevent a malfunction caused by lightning surge, to eliminate the need of maintenance and to automatically recover an original state.SOLUTION: A positioner 201 comprises: a surge protection circuit 7 for protecting an internal circuit of the positioner by causing a surge current that attempts to enter the internal circuit via a pair of signal lines L (L1 and L2) to flow to a ground line GND; and a surge protection circuit operation detection part 8 for detecting that the surge protection circuit 7 protects the internal circuit of the positioner 201 from the surge current. If the surge protection circuit operation detection part 8 detects operation of the surge protection circuit 7, a control part 1 (1A) keeps a current signal to an electropneumatic conversion part in a previous state. Thus, a control valve maintains an aperture at that time and the malfunction caused by lightning surge is prevented. After the lapse of a predetermined time, the state where the current signal to the electropneumatic conversion part is kept in the previous state is cancelled.SELECTED DRAWING: Figure 1
Inventors:
MURATA KOICHIRO
Application Number:
JP2015032560A
Publication Date:
September 01, 2016
Filing Date:
February 23, 2015
Export Citation:
Assignee:
AZBIL CORP
International Classes:
F15B9/09; H02H9/04
Domestic Patent References:
| JP2012208818A | 2012-10-25 | |||
| JP2007164230A | 2007-06-28 | |||
| JP2013088917A | 2013-05-13 | |||
| JPS593738U | 1984-01-11 |
Attorney, Agent or Firm:
Masaki Yamakawa
Shigeki Yamakawa
Shigeki Yamakawa
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