Abstract: An interface circuit for a telephone instrument forming part of a character display phone PBX system. The circuit is connected to receive data signals indicative of the condition of the character display and keyboard portions of the instrument, and to store and manage the incoming data and produce a serial RS232 output for communication of the data to a computer or terminal device. The interface enables the use of a computing device to store large amounts of information related to potential calling parties and called parties which may be identified in the display of the telephone instrument and also to associate such information with messages entered into the computer via the keyboard. The overall system thus enables custom answering of a multiplicity of lines of such a character display phone system and use of a single multi-line phone as a messaging center.

Abstract: A triac functions as an electronic switch to intermittently connect the AC power circuit to a load, and is directly connected to the output of a 1422 integrated circuit timer which turns the triac on and off according to a controlled cycle. The timer functions as an astable multivibrator which alternately produces high or low output voltages responsive to movement of a control voltage between high and low trigger voltage levels. A charging circuit, including a capacitor and variable resistor, is connected directly between the DC power supply and the timer input to produce an increasing control voltage; and the control voltage is discharged through the timer to produce a decreasing control voltage which determines the duty cycle. The duty cycle is variable by means of a variable resistor in the charging and discharge circuits; and the control includes calibration for the time base.

Abstract: This data transmitting apparatus is illustrated in a system for the remote reading of water meters. It includes a passive transmitter operated by the meter, a receiver including a source of energy, and means for connecting the receiver and its energy source to the transmitter. The receiver includes electrical loading means enabling it to read a submerged meter. The receiver is compatible with one type of transmitter having 14 output wires and with another type having only three. The data, e.g., a reading of a meter, is transmitted as binary data in a word of 16 characters, each comprising four bits. A pulse coding system is insensitive to noise, and includes a first bit detector for each character, and a final character detector for each word. The receiver detects open circuits in the transmitter and produces an error signal in response to such open circuits. The receiver and transmitter may be coupled through a manual connector.