JPH01137646U - - Google Patents
Info
- Publication number
- JPH01137646U JPH01137646U JP3432888U JP3432888U JPH01137646U JP H01137646 U JPH01137646 U JP H01137646U JP 3432888 U JP3432888 U JP 3432888U JP 3432888 U JP3432888 U JP 3432888U JP H01137646 U JPH01137646 U JP H01137646U
- Authority
- JP
- Japan
- Prior art keywords
- detection
- frequency
- dtmf signal
- specific frequency
- circuit
- 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 18
- 238000010586 diagram Methods 0.000 description 2
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3432888U JPH01137646U (el) | 1988-03-14 | 1988-03-14 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3432888U JPH01137646U (el) | 1988-03-14 | 1988-03-14 |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH01137646U true JPH01137646U (el) | 1989-09-20 |
Family
ID=31261041
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP3432888U Pending JPH01137646U (el) | 1988-03-14 | 1988-03-14 |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH01137646U (el) |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5550765A (en) * | 1978-10-06 | 1980-04-12 | Nippon Telegr & Teleph Corp <Ntt> | Digital signal receiver |
JPS56131245A (en) * | 1980-03-19 | 1981-10-14 | Hitachi Ltd | Signal detecting circuit |
-
1988
- 1988-03-14 JP JP3432888U patent/JPH01137646U/ja active Pending
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5550765A (en) * | 1978-10-06 | 1980-04-12 | Nippon Telegr & Teleph Corp <Ntt> | Digital signal receiver |
JPS56131245A (en) * | 1980-03-19 | 1981-10-14 | Hitachi Ltd | Signal detecting circuit |