公开(公告)号：US5357609A

公开(公告)日：1994-10-18

申请号：US858319

申请日：1992-03-25

申请人： Robert E. Sellers ,  Gary D. Alford

发明人： Robert E. Sellers ,  Gary D. Alford

IPC分类号： H04B3/20 ,  G06F13/38

CPC分类号： H04B3/20

摘要： An embodiment of the present invention is a site controller that comprises a microcomputer with a RAM for main memory and an EPROM for program memory, an interface for accepting RS-485 data and voice communication on respective differential wire pairs from a daisy chain of student response keypad terminals, a public telephone data access arrangement with hybrid for sending and receiving voice over a dial-up line, a universal asynchronous receiver-transmitter for data communication by modem with a remote host site via an X.25 PAD and an audio processor for half-duplex communication between an instructor and a student that has voltage controlled amplifiers and side chain devices that reduce audio amplifier gain during periods of silence in order to eliminate feedback howl and adjustable delay and threshold devices for gating the respective channels through in the half-duplex mode.

摘要翻译： 本发明的实施例是一种现场控制器，其包括具有用于主存储器的RAM和用于程序存储器的EPROM的微型计算机，用于接收来自学生响应的菊花链的相应差分线对上的RS-485数据和语音通信的接口 键盘终端，用于通过拨号线路发送和接收语音的混合的公共电话数据访问装置，用于通过X.25 PAD的调制解调器与远程主机站点进行数据通信的通用异步接收机 - 发射机，以及用于 讲师和具有电压控制放大器和侧链装置的学生之间的半双工通信，其在静默期间减少音频放大器增益，以消除在半衰期期间门控各个通道的反馈嚎叫和可调延迟和阈值装置， 双工模式。

公开(公告)号：US5329620A

公开(公告)日：1994-07-12

申请号：US858318

申请日：1992-03-25

申请人： Gary D. Alford ,  Robert E. Sellers

发明人： Gary D. Alford ,  Robert E. Sellers

IPC分类号： G09B5/14 ,  G06F13/00

CPC分类号： G09B5/14

摘要： A daisy chain voice-data terminal for communicating data and voice signals between remote locations, comprising, according to an embodiment of the present invention, a microcomputer with a RAM for main memory and an EPROM for program memory, a membrane keypad connected to an input port of the microcomputer, a liquid crystal display adjacent to the keypad and connected to an output port of the microcomputer, a microphone and preamplifier, a differential output audio amplifier, a relay controlled by the microcomputer to switch the differential output audio amplifier on and off a daisy chain cable connected to other response keypads and a site controller, an RS-485 serial input/output to interface the microcomputer to the daisy chain cable, a switching regulator to provide five volts to the logic circuits, and a separate three-terminal linear regulator to supply five volts to the audio circuits. At each response keypad, the wiring for the audio channel is cross connected to balance out any noise that may be otherwise induced in the audio signal.

摘要翻译： 一种用于在远程位置之间传送数据和语音信号的菊花链语音数据终端，包括：根据本发明的实施例，具有用于主存储器的RAM和用于程序存储器的EPROM的微型计算机，连接到输入端的膜键盘 微型计算机端口，与键盘相邻并连接到微计算机的输出端口的液晶显示器，麦克风和前置放大器，差分输出音频放大器，由微型计算机控制的继电器，以打开和关闭差分输出音频放大器 连接到其他响应键盘的菊花链电缆和现场控制器，RS-485串行输入/输出将微型计算机连接到菊花链电缆，开关稳压器为逻辑电路提供5伏特，以及单独的三端子 线性稳压器为音频电路提供五伏特。 在每个响应键盘上，音频通道的布线交叉连接，以平衡音频信号中可能会引起的任何噪音。