Abstract A telephone visual paging system that is actuated by an audio signal. The audio input current is used to power two or more light emitting diodes which are housed on a telephone receiver. Other than the audio signal power supply, no separate power supply system is needed to power these light sources. By superimposing variations caused by the audio input signal on the periodic switching signals from a multivibrator, the light emitting diodes can generate a semaphore radiation action to get the visual attention of an observer. This invention is particularly useful in hazardous gaseous environments, like coal mines, where electric wiring connections and the possibility of ignitions from electric sources should be minimized.
Inventors
👤 G Conroy
👤 H Parkinson
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-30 15:33
CPC Classifications
H; H04; H04M; H04M19/00; H04M19/02; H04M19/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
83 words
A visual paging system for attracting the attention of observers comprising: means for inputting an amplified audio signal into the system; circuitry to change the inputted audio signal to pulsating direct current signals; a plurality of light emitting diodes operatively connected to said pulsating circuit; and a switching circuit connected to said light emitting diodes such that in an operative state, it continuously switches the signals received by the light emitting diodes from the pulsating circuit when there is an audio input signal.
Claim 2
Dependent Claim
83 words
A visual paging system for attracting the attention of observers comprising: means for inputting an amplified audio signal into the system; circuitry to change the inputted audio signal to pulsating direct current signals; a plurality of light emitting diodes operatively connected to said pulsating circuit; and a switching circuit connected to said light emitting diodes such that in an operative state, it continuously switches the signals received by the light emitting diodes from the pulsating circuit when there is an audio input signal.
Claim 3
Dependent Claim
22 words
The system of claim 1 wherein at least two of said light emitting diodes are connected by parallel circuits to each other.
Claim 4
Dependent Claim
19 words
The system of claim 1 wherein said pulsating circuitry comprises a rectifier bridge circuit in parallel with a capacitor.
Claim 5
Dependent Claim
25 words
The system of claim 1 wherein said switching circuit comprises an astable multivibrator connected by solid state devices to each of said light emitting diodes.
Claim 6
Dependent Claim
30 words
The system of claim 1 wherein said system is contained in a single housing and said light emitting diodes consist of four diodes, two on opposite sides of said housing.