JPS54147449A - Protective circuit - Google Patents
Protective circuitInfo
- Publication number
- JPS54147449A JPS54147449A JP5595078A JP5595078A JPS54147449A JP S54147449 A JPS54147449 A JP S54147449A JP 5595078 A JP5595078 A JP 5595078A JP 5595078 A JP5595078 A JP 5595078A JP S54147449 A JPS54147449 A JP S54147449A
- Authority
- JP
- Japan
- Prior art keywords
- transistor
- load
- base
- approached
- potential
- 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
Landscapes
- Protection Of Static Devices (AREA)
- Electronic Switches (AREA)
Abstract
PURPOSE: To prevent a damage to the load and ruin of the transistor which drives and controls the load by decreasing the potential at base and collector of the transistor which control the load transistor when the voltage applied to the load exceeds a specified value.
CONSTITUTION: When the DC output voltage applied to the integrated circuit 10 is made so high that it exceeds the voltage of Zener diode 16, a current flows in the resistances 17 and 18 connected with each other in series through the Zener diode 16. By this, base currents flow in the respective transistors 20, 22 the transistor 20 is approached to "on", the potential at base of the transistor 14 reduces and the transistor 14 is approached to "off". Also a base current flows in the transistor 22, which is approached to "on". Thus the potential at collector of the transistor 14 decreases. When the transistor 14 is not operated, the base current is not fed to the transistor 5 which is added to the integrated circuit 10 and drives the load 4, the transistor 5 is turned off. Therefore a damage to the load and the ruin of element can be prevented.
COPYRIGHT: (C)1979,JPO&Japio
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5595078A JPS54147449A (en) | 1978-05-11 | 1978-05-11 | Protective circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5595078A JPS54147449A (en) | 1978-05-11 | 1978-05-11 | Protective circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS54147449A true JPS54147449A (en) | 1979-11-17 |
Family
ID=13013346
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5595078A Pending JPS54147449A (en) | 1978-05-11 | 1978-05-11 | Protective circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS54147449A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5834599U (en) * | 1981-08-31 | 1983-03-07 | 日本電気株式会社 | protection circuit |
| JPH0253230U (en) * | 1988-10-03 | 1990-04-17 |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54141555A (en) * | 1978-04-26 | 1979-11-02 | Nec Corp | Electric circuit |
-
1978
- 1978-05-11 JP JP5595078A patent/JPS54147449A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54141555A (en) * | 1978-04-26 | 1979-11-02 | Nec Corp | Electric circuit |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5834599U (en) * | 1981-08-31 | 1983-03-07 | 日本電気株式会社 | protection circuit |
| JPH0323709Y2 (en) * | 1981-08-31 | 1991-05-23 | ||
| JPH0253230U (en) * | 1988-10-03 | 1990-04-17 |
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