JPH033865U - - Google Patents
Info
- Publication number
- JPH033865U JPH033865U JP6455789U JP6455789U JPH033865U JP H033865 U JPH033865 U JP H033865U JP 6455789 U JP6455789 U JP 6455789U JP 6455789 U JP6455789 U JP 6455789U JP H033865 U JPH033865 U JP H033865U
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- telephone
- detection circuit
- telephone line
- set value
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000001514 detection method Methods 0.000 claims description 8
Description
図示した回路は、本考案のフツク状態検出回路
の一実施例である。
主な図番の説明、6……ダイオードブリツジ回
路、7……電池、9……制御回路、10……フツ
クスイツチ、12……閉結用トランジスター、1
6……制御トランジスター、20……電圧検出回
路、26……検出電圧切換用スイツチ、27……
第1ツエナーダイオード、28……第2ツエナー
ダイオード、29……発光ダイオード。
The illustrated circuit is one embodiment of the hook state detection circuit of the present invention. Explanation of main drawing numbers, 6... Diode bridge circuit, 7... Battery, 9... Control circuit, 10... Hook switch, 12... Closing transistor, 1
6... Control transistor, 20... Voltage detection circuit, 26... Detection voltage switching switch, 27...
First Zener diode, 28... Second Zener diode, 29... Light emitting diode.
Claims (1)
話機において、他方の電話機のオフフツク状態へ
の切換に伴なう電話回線の電圧低下を検出すると
ともに電話回線の電圧が設定値より低下したとき
表示素子を駆動せしめる電圧検出回路と、接続さ
れる電話回線の電圧に対応して切換えられるとと
もに前記電圧検出回路の設定値を切換える検出電
圧切換用スイツチとより成る電話機のフツク状態
検出回路。 In a telephone with multiple telephones connected in parallel to the same line, an element that detects a voltage drop in the telephone line due to the switching of the other telephone to an off-hook state and indicates when the voltage of the telephone line drops below a set value. 1. A hook state detection circuit for a telephone, comprising a voltage detection circuit for driving the voltage detection circuit, and a detection voltage switching switch that is switched in accordance with the voltage of a connected telephone line and that switches a set value of the voltage detection circuit.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6455789U JPH033865U (en) | 1989-06-01 | 1989-06-01 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6455789U JPH033865U (en) | 1989-06-01 | 1989-06-01 |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH033865U true JPH033865U (en) | 1991-01-16 |
Family
ID=31595611
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP6455789U Pending JPH033865U (en) | 1989-06-01 | 1989-06-01 |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH033865U (en) |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60105355A (en) * | 1983-11-14 | 1985-06-10 | Nec Corp | Telephone set |
JPS6436251A (en) * | 1987-07-31 | 1989-02-07 | Nec Corp | Line closing control circuit |
-
1989
- 1989-06-01 JP JP6455789U patent/JPH033865U/ja active Pending
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60105355A (en) * | 1983-11-14 | 1985-06-10 | Nec Corp | Telephone set |
JPS6436251A (en) * | 1987-07-31 | 1989-02-07 | Nec Corp | Line closing control circuit |
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