Title:
【発明の名称】フェールセーフ状態検出回路
Document Type and Number:
Japanese Patent JP3185145
Kind Code:
B2
Abstract:
A circuit for detecting whether the level of an electrical signal having a preselected polarity is above a preselected value, is powered by DC of the opposite polarity. This prevents current leakage within the detector circuit from simulating the level of the electrical signal. Such a circuit is particularly suited for detecting the current level provided by a flame sensor in a combustion control system. The preferred embodiment has a capacitor which is charged by the circuit and then discharged by the electrical signal. The time required to discharge the capacitor to a preselected level indicates the level of the electrical signal. A second embodiment uses a comparator in a feedback loop which allows sensing the level of a voltage outside of the voltage range defined by the comparator's power supply.
Inventors:
Shigafus, Paul Yi
Application Number:
JP50855793A
Publication Date:
July 09, 2001
Filing Date:
October 22, 1992
Export Citation:
Assignee:
Honeywell Incorporated
International Classes:
F23N5/08; F23N5/12; (IPC1-7): F23N5/12
Domestic Patent References:
| JP6057126A | ||||
| JP5833026A |
Attorney, Agent or Firm:
Masaki Yamakawa (5 outside)
Previous Patent: フルフェース車輪アセンブリーとその製造方法
Next Patent: LIQUID BATH DRAWING TREATMENT OF ACRYLIC FIBER TOW
Next Patent: LIQUID BATH DRAWING TREATMENT OF ACRYLIC FIBER TOW