Plantronics, Inc.

Choice Communication Products, Inc.

Rickey R Walker

David O Hanon

A telephone having a non-volatile circuit for automatically dialing 911 upon depression of a single key includes an oscillator activated in response to depression of the key for transmitting clock pulses to a counter. Certain of the output signals from the counter are applied to switches in sequence. The switches are connected to selective column and row leads of the telephone dialer circuit corresponding to the digits in the telephone number to be dialed. The switches short together the respective column and row leads so that the dialer reacts in the same manner it would when the keys of those digits are depressed on the telephone keypad. An output pulse from the counter resets the circuit after the switch connects together the column and row leads of the last digit of the telephone number.

Non-volatile automatic telephone number dialer circuit

An apparatus 10 is employed for interfacing a telephone handset 18 to a telephone network. Typically, a telephone handset has one of a variety of different microphones disposed therein, such as carbon, electret, etc., where each type of microphone has a different output level and impedance. Conversely, the telephone network with which the microphone is to be interfaced has a preselected input impedance and signal requirement intended to match only one type of microphone. The apparatus 10 includes a plurality of switches 82, 84, 86, 88 and resistors 90, 92, 94 that are manually switchable into the circuit either separately or in combination to match the output impedance and signal level of the microphone with the input impedance and signal level of the telephone network. Alternatively, in a second embodiment of the instant apparatus, a variable resistor is employed to match the output impedance and signal level of the microphone with the input impedance and signal level of the telephone network.

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Ringgold, GA, United States of America

Rickey R Walker