JPH01142211U - - Google Patents
Info
- Publication number
- JPH01142211U JPH01142211U JP3747388U JP3747388U JPH01142211U JP H01142211 U JPH01142211 U JP H01142211U JP 3747388 U JP3747388 U JP 3747388U JP 3747388 U JP3747388 U JP 3747388U JP H01142211 U JPH01142211 U JP H01142211U
- Authority
- JP
- Japan
- Prior art keywords
- input impedance
- operational amplifier
- photocoupler
- turned
- power source
- 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
- 238000010586 diagram Methods 0.000 description 4
Landscapes
- Electronic Switches (AREA)
- Amplifiers (AREA)
Description
第１図は本考案の一実施例を示す回路構成図、
第２図及び第３図はそれぞれ本考案の別の実施例
を示す回路構成図、第４図は従来の演算増幅器の
基本構成を示す回路図、第５図は従来の問題点を
説明するための図である。
１，９……演算増幅器、２……入力抵抗、３，
１０……帰還抵抗、４，１１……ホトカプラ、５
，１２……発光素子、６，１３……受光素子、７
……電流制限用抵抗、８……ツエナーダイオード
、２１，２２……電源。
FIG. 1 is a circuit diagram showing an embodiment of the present invention;
2 and 3 are circuit configuration diagrams showing another embodiment of the present invention, FIG. 4 is a circuit diagram showing the basic configuration of a conventional operational amplifier, and FIG. 5 is for explaining the problems of the conventional operation. This is a diagram. 1, 9...Operation amplifier, 2...Input resistance, 3,
10...Feedback resistor, 4, 11...Photocoupler, 5
, 12... Light emitting element, 6, 13... Light receiving element, 7
... Current limiting resistor, 8... Zener diode, 21, 22... Power supply.
Claims (1)
と、上記演算増幅器の入力側に受光側を持ち、発
光側を上記電源に接続したホトカプラとを具備し
、このホトカプラにより電源がオンになると入力
インピーダンスを下げ、オフになるとその入力イ
ンピーダンスを上げるようにしたことを特徴とす
る増幅回路。 It is equipped with an operational amplifier, a power source that drives the operational amplifier, and a photocoupler that has a light receiving side on the input side of the operational amplifier and whose emitting side is connected to the power source.The photocoupler changes the input impedance when the power is turned on. An amplifier circuit characterized in that the input impedance is lowered and the input impedance is increased when the input impedance is turned off.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3747388U JPH01142211U (en) | 1988-03-22 | 1988-03-22 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3747388U JPH01142211U (en) | 1988-03-22 | 1988-03-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01142211U true JPH01142211U (en) | 1989-09-29 |
Family
ID=31264053
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3747388U Pending JPH01142211U (en) | 1988-03-22 | 1988-03-22 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01142211U (en) |
-
1988
- 1988-03-22 JP JP3747388U patent/JPH01142211U/ja active Pending