Title:
HOT-LINE ALARM
Document Type and Number:
Japanese Patent JP3328866
Kind Code:
B2
Abstract:
PURPOSE: To provide a hot-line alarm of a compact structure which generates an alarm by cutting an unnecessary electric noise and receiving only an AC signal generated from a high voltage hot-line.
CONSTITUTION: This alarm consists of an oscillator 31 which generates AC signal of a specific frequency in synchronism with the commercial frequency of the high voltage hot-line, a detector 32 which detects the AC signal from the oscillator 31, an impedance converter 33 which performs impedance conversion to the detected signal, a band-passing amplifier 34 which amplifies only frequencies within a specific range of the impedance-converted signal with a specific frequency the center as, a signal level discrimination unit 35 which discriminates a signal above a necessary level as to the signal from the amplifier 34, an alarm circuit consisting of a redundant circuit 36 which cuts an unnecessary noise in the output signal of the signal level discrimination unit 35 and a time-limit circuit 37 with stop conditions which generates an alarm for a certain time, and an alarm means 39 (42 and 45) which operates with the output signal of the alarm circuit.
Inventors:
Yasuo Yokoyama
Kozo Ando
Kozo Ando
Application Number:
JP4653995A
Publication Date:
September 30, 2002
Filing Date:
February 10, 1995
Export Citation:
Assignee:
Obex Co., Ltd.
Sadao Masuda
Sadao Masuda
International Classes:
A42B3/00; G01R19/155; G08B1/08; G08B21/00; G08B21/02; (IPC1-7): G08B21/02; A42B3/00; G01R19/155
Domestic Patent References:
| JP3243866A | ||||
| JP723285U | ||||
| JP63143528U | ||||
| JP5669832U | ||||
| JP6169228U | ||||
| JP5637068U | ||||
| JP467905Y1 |
Attorney, Agent or Firm:
Masahiro Koda