FR2719434A1 - Cordless telephone FM radio transceiver e.g. for deaf user - Google Patents

Abstract

The transceiver includes a transmitter which is coupled to a connector (1) which includes an electronic circuit connected to a telephone line by a plug (3). The transmitter includes a potentiometer which is used to increase the power of a ringing signal until the conversation is rendered inaudible. The ringing receiver is in the form of a casing (4) with a warning light (7), a volume control (5) and a clip (6) for hooking to the belt of the user. Ringing of the telephone is indicated by the warning light which flashes at a regular frequency.

Description

1 and view The present invention is a device for hearing /

alarm

  on the phone without having to stay near the ringer.

  The conventional method is to install wires and a

  additional bell in each room.

  For a deaf one must add to each ring in addition to the wires

  an indicator that flashes when there is a call on minitel.

  The device according to the invention prevents the user from installing the

  son. The accompanying drawings illustrate the device of the invention.

  It includes a box 1 which is a specific pull-out socket in which an electronic circuit is arranged which includes a low frequency preamplifier stage and a high frequency amplifier stage - Tl emits the frequency modulated radioelectric waves which are picked up by a receiver box 4 equipped

frequency modulation.

  The pull-out socket plugged into the telephone socket is connected to J1 which receives the pulses from the bell. The circuit is supplied by a transformer with 220 V AC input and 9 V continuous output. Thus designed the ringing pulses are amplified and transmitted by the transmitter circuit and picked up by an FM receiver within a 30m radius. The power of these pulses is measured by the

  adjustment of potentiometer Pl which can be adjusted to saturation.

  The transmitter and receiver are tuned by the capacitor

  CV1 of the transmitter and that of the receiver (frequency adjustment).

  The appended drawing illustrates by way of example an embodiment of the transmitting electronic circuit. The receiver box being a conventional FM radio receiver provided with an indicator which flashes as soon as

that it receives impulses.

  The transmission and reception mode is purely given

indicative and in no way limitative.

  Modifications can be made without departing from the present invention which is a cordless telephone ringing system. The signals of the ringing pulses applied to the input J1 are preamplified by the transistor T1 of the BC547 type. The P1 functions as an input voltage limiter to obtain the low frequency phase saturation of the ringing pulses at the base of T1. The capacitor C4 serves as a coupling for the signals from the base of T1 polarized and supplied by the resistors R8 and R6 and decoupled by C7. Then these amplified signals and adapted by the potentiometer P1 are coupled to the base of T2 by C5. The transistor T2 of type BC550 serves as an oscillator and a high frequency amplifier. It is polarized by resistors Rll and R8 and decoupled by C6. To its collector is connected the oscillating circuit of the HARTLEY type which includes 2 inductors Si and S2 with mandrels, arranged in parallel, 2 capacitors C8 and C9 and a variable capacitor CVI which allows the transmission frequency to be adjusted from Mhz to 150 Mhz It should be noted that: - the J1 input is connected to the telephone line by the terminals of

the pull-out socket.

  - if the setting of potentiometer P 1 is at minimum, there is saturation of the amplification of the ringing signals, which only

  increase the power of these signals picked up by the receiver unit.

  - this setting avoids eavesdropping on the telephone conversation.The voice is inaudible due to the distortion

dae to saturation.

  - if the signals received are at a regular rate, it is

there is a phone call.

  -if the receiver box indicator light flashes at a regular rate

  the deaf person recognizes that it is a call on the telephone line.

  The supply by the transformer - charger is done by connecting the 9volts output continuously to J2. The current is filtered by the resistors R2 R3 and decoupled by the capacitors Cl C2 C3. As soon as the transmitter circuit is started by the inverter I, the control lamp protected by Ri lights up. Because the circuit consumption is OMa and the charger

  only charges OMa when there is consumption the transformer can

  be in operation continuously without heating.

  The device according to the invention is particularly intended for

  hearing impaired and deaf to amplify the impulses of sound-

  phone nerie Between the phone ringing and the box

  sound receiver there is no wire connection.

Claims (3)

  1 / Transmitting / receiving system by radio waves in modula-   frequency, without any wire connection, to hear and view   read the ringtone of the telephone, characterized in that the transmitter is installed in the specific pull-out socket 1, in which is arranged   an electronic circuit, connected to the telephone line by its branch   in socket 3 (line input) and the sound receiver   4 which is in the form of a box 4 provided with a light   7, a volume control 5 and a clip 6 for the dear to the user's belt.   2 / transmission-reception system according to claim 1 character-   laughed at in that the transmitter circuit is equipped with a potentiometer P1 to increase the power of the ringing signals until saturation in order to make the telephone conversation which stay discreet.   3 / transceiver system according to claim 1 characterized in that the telephone ringing is displayed by means of the indicator 7 of the receiver unit 4 said indicator flashing at a rate   regular as soon as there is a phone call.