JPS55125754A - Current limit system at subscriber line grounding - Google Patents
Current limit system at subscriber line groundingInfo
- Publication number
- JPS55125754A JPS55125754A JP3228779A JP3228779A JPS55125754A JP S55125754 A JPS55125754 A JP S55125754A JP 3228779 A JP3228779 A JP 3228779A JP 3228779 A JP3228779 A JP 3228779A JP S55125754 A JPS55125754 A JP S55125754A
- Authority
- JP
- Japan
- Prior art keywords
- subscriber line
- current
- potential
- relay
- current limit
- 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
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q3/00—Selecting arrangements
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Monitoring And Testing Of Exchanges (AREA)
- Interface Circuits In Exchanges (AREA)
Abstract
PURPOSE:To enable to prevent burning out of current supply relay at subscriber line grounding with a simple circuit constitution, by inserting a resistance to the subscriber line corresponding to the state of subscriber line potential at grounding. CONSTITUTION:The resistance R1, constant voltage diode D, and transistor Tr constitute the circuit detecting the potential of the subscriber line L. When the subscriber line L is grounded, current increases at the subscriber line L, the potential of the subscriber line L is close to ground, Tr is cut off, the relay A is restored and the contact (a) is selected to the current limit resistance R2 side. As a result, the current flowing to the subscriber line L is limited, the current flowing to the current supply relay LR is reduced, and failure such as relay burning out can be avoided.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3228779A JPS55125754A (en) | 1979-03-22 | 1979-03-22 | Current limit system at subscriber line grounding |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3228779A JPS55125754A (en) | 1979-03-22 | 1979-03-22 | Current limit system at subscriber line grounding |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS55125754A true JPS55125754A (en) | 1980-09-27 |
Family
ID=12354741
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3228779A Pending JPS55125754A (en) | 1979-03-22 | 1979-03-22 | Current limit system at subscriber line grounding |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS55125754A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03263964A (en) * | 1990-03-14 | 1991-11-25 | Fujitsu Ltd | Feeding circuit |
-
1979
- 1979-03-22 JP JP3228779A patent/JPS55125754A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03263964A (en) * | 1990-03-14 | 1991-11-25 | Fujitsu Ltd | Feeding circuit |
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