JPH0292527U - - Google Patents
Info
- Publication number
- JPH0292527U JPH0292527U JP128089U JP128089U JPH0292527U JP H0292527 U JPH0292527 U JP H0292527U JP 128089 U JP128089 U JP 128089U JP 128089 U JP128089 U JP 128089U JP H0292527 U JPH0292527 U JP H0292527U
- Authority
- JP
- Japan
- Prior art keywords
- keyboard
- circuit
- optical isolator
- connection determination
- explanatory diagram
- 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
- 230000003287 optical effect Effects 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 5
Landscapes
- Input From Keyboards Or The Like (AREA)
Description
第１図はこの考案の一実施例によるキーボード
接続判定回路図、第２図は光アイソレータの回路
説明図、第３図はキーボード接続時のキーボード
接続判定回路動作説明図、第４図はキーボード未
接続時のキーボード接続判定回路動作説明図、第
５図はキーボード接続時の通常の動作説明図であ
る。第６図は従来のキーボード接続判定回路、第
７図は第６図における判定プログラムのフローチ
ヤート図である。
図において２はキーボード、１４は光アイソレ
ータである。なお、図中、同一符号は同一または
相当部分を示す。
Fig. 1 is a circuit diagram for determining keyboard connection according to an embodiment of this invention, Fig. 2 is an explanatory diagram of the circuit of an optical isolator, Fig. 3 is an explanatory diagram of the operation of the circuit for determining keyboard connection when a keyboard is connected, and Fig. 4 is an illustration of the operation of the keyboard connection judgment circuit when the keyboard is not connected. FIG. 5 is an explanatory diagram of the operation of the keyboard connection determination circuit when the keyboard is connected. FIG. 5 is an explanatory diagram of the normal operation when the keyboard is connected. FIG. 6 is a conventional keyboard connection determination circuit, and FIG. 7 is a flowchart of the determination program in FIG. In the figure, 2 is a keyboard, and 14 is an optical isolator. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.
Claims (1)
ータとキーボードの内部抵抗を利用して構成した
ことを特徴とするキーボード接続判定回路。 A keyboard connection determination circuit, characterized in that the circuit for determining whether or not a keyboard is connected is configured using an optical isolator and an internal resistance of the keyboard.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP128089U JPH0292527U (en) | 1989-01-10 | 1989-01-10 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP128089U JPH0292527U (en) | 1989-01-10 | 1989-01-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0292527U true JPH0292527U (en) | 1990-07-23 |
Family
ID=31201038
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP128089U Pending JPH0292527U (en) | 1989-01-10 | 1989-01-10 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0292527U (en) |
-
1989
- 1989-01-10 JP JP128089U patent/JPH0292527U/ja active Pending