JPH0238853U - - Google Patents
Info
- Publication number
- JPH0238853U JPH0238853U JP11739488U JP11739488U JPH0238853U JP H0238853 U JPH0238853 U JP H0238853U JP 11739488 U JP11739488 U JP 11739488U JP 11739488 U JP11739488 U JP 11739488U JP H0238853 U JPH0238853 U JP H0238853U
- Authority
- JP
- Japan
- Prior art keywords
- external device
- doorphone
- circuit
- constant current
- bridge
- 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
- 238000006243 chemical reaction Methods 0.000 claims 2
- 230000008054 signal transmission Effects 0.000 claims 2
- 230000005540 biological transmission Effects 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 2
Description
第１図は本考案の一実施例の回路ブロツク図、
第２図は従来例の回路ブロツク図である。
１０，１４…定電流回路、１１，１５…ホイツ
トストーンブリツジ、１２…送話増幅器、１３…
受話増幅器。
FIG. 1 is a circuit block diagram of an embodiment of the present invention.
FIG. 2 is a circuit block diagram of a conventional example. 10, 14... constant current circuit, 11, 15... Whitstone bridge, 12... transmitter amplifier, 13...
Receiving amplifier.
Claims (1)
通話路を形成するドアホン接続回路において、 ドアホン入力端子間をブリツジの一辺とする、
抵抗素子によるホイツトストーンブリツジと、前
記ホイツトストーンブリツジに定電流を供給する
定電流回路とを有し、ドアホンへの電力供給が前
記定電流回路からなされるとともに、外部装置か
らドアホンへの通話電流を前記定電流に重畳し、
ドアホンに信号を伝達する信号送話経路およびド
アホンから外部装置への通話電流を、前記ホイツ
トストーンブリツジの中点間に接続された差動増
幅器を介して、外部装置へ伝達する信号受話経路
からなる４線式回路を備えていることを特徴とす
るドアホン接続回路。 ２ 請求項１記載のドアホン接続回路において、
外部装置からドアホンへ信号を伝達する信号送話
経路、ドアホンから信号を外部装置へ伝達する信
号受話経路からなる４線式回路が２線・４線変換
回路を経て、外部装置へ接続していることを特徴
とするドアホン接続回路。 ３ 請求項２記載のドアホン接続回路において、
外部装置との接続は、ホイツトストーンブリツジ
とホイツトストーンブリツジに定電流を供給する
定電流回路からなる２線・４線変換回路であり、
外部装置はホイツトストーンブリツジの１の抵抗
に並列接続され、ドアホンから外部装置への通話
電流が前記定電流回路に重畳し、外部装置からド
アホンへの通話電流が前記ホイツトストーンブリ
ツジの中点間に接続された差動増幅器を介して伝
達されることを特徴とするドアホン接続回路。[Scope of Claim for Utility Model Registration] 1. In a door phone connection circuit that supplies power to the door phone and forms a communication path with an external device, one side of the bridge is between the door phone input terminals.
It has a Whitstone bridge made of a resistive element, and a constant current circuit that supplies a constant current to the Whitstone bridge, and power is supplied to the doorphone from the constant current circuit and from an external device to the doorphone. superimpose the communication current on the constant current,
A signal transmission path for transmitting a signal to the doorphone; and a signal reception path for transmitting a communication current from the doorphone to the external device to the external device via a differential amplifier connected between the midpoints of the Whitstone bridge. A door intercom connection circuit characterized by comprising a four-wire circuit consisting of. 2. The door intercom connection circuit according to claim 1,
A 4-wire circuit consisting of a signal transmission path that transmits signals from the external device to the doorphone, and a signal reception path that transmits signals from the doorphone to the external device is connected to the external device via a 2-wire/4-wire conversion circuit. A doorbell connection circuit characterized by: 3. In the door phone connection circuit according to claim 2,
The connection with external devices is a 2-wire/4-wire conversion circuit consisting of a Whitstone bridge and a constant current circuit that supplies constant current to the Whitstone bridge.
The external device is connected in parallel to the resistor 1 of the Whetstone bridge, and the communication current from the doorphone to the external device is superimposed on the constant current circuit, and the communication current from the external device to the doorphone is connected in parallel to the resistor 1 of the Whetstone bridge. A door intercom connection circuit characterized in that transmission is performed via a differential amplifier connected between midpoints.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11739488U JPH0238853U (en) | 1988-09-08 | 1988-09-08 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11739488U JPH0238853U (en) | 1988-09-08 | 1988-09-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0238853U true JPH0238853U (en) | 1990-03-15 |
Family
ID=31360819
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11739488U Pending JPH0238853U (en) | 1988-09-08 | 1988-09-08 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0238853U (en) |
-
1988
- 1988-09-08 JP JP11739488U patent/JPH0238853U/ja active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5001746A (en) | Transmission control unit | |
| JPH0238853U (en) | ||
| JPH0533094Y2 (en) | ||
| JP2523457B2 (en) | Interface Module | |
| JPS60189145U (en) | data transceiver | |
| JPS61136657U (en) | ||
| JPS646608Y2 (en) | ||
| JPS6022688Y2 (en) | signal transmission device | |
| JPS59127351U (en) | wireless communication device | |
| JPS62152527U (en) | ||
| JPS6347654U (en) | ||
| JPS59157374U (en) | button telephone device | |
| JPS6066150U (en) | telephone circuit | |
| JPS61206347U (en) | ||
| JPS63120435U (en) | ||
| JPS61136658U (en) | ||
| JPS6437146U (en) | ||
| JPS61104659U (en) | ||
| JPS62112246U (en) | ||
| KR880001121A (en) | 4-wire / 2-wire hybrid circuit of 2-wire full duplex modem | |
| JPS6247264U (en) | ||
| JPS61121063U (en) | ||
| JPH0186358U (en) | ||
| JPS6338435U (en) | ||
| JPS6352333U (en) |