Browse Prior Art Database

Audio Alarm

IP.com Disclosure Number: IPCOM000084614D
Original Publication Date: 1975-Dec-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 25K

Publishing Venue

IBM

Related People

Gratowski, F: AUTHOR [+2]

Abstract

Many machines have visual indicators which show alarm conditions. If someone is not in a position to view the visual indicator, he may not know that an alarm condition exists. The device shown senses a visual indication and produces an audio alarm.

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Audio Alarm

Many machines have visual indicators which show alarm conditions. If someone is not in a position to view the visual indicator, he may not know that an alarm condition exists. The device shown senses a visual indication and produces an audio alarm.

The device includes a transistor 10, a photocell 11, and a buzzer 12. The transistor bias is controlled by variable resistor 15 and the volume of the buzzer 12 is controlled by variable resistor 16. A battery 14 activates the circuit and a switch 13 turns the circuit on or off.

The conduction through transistor 10 is controlled by the resistance of photocell 11. When the resistance of photocell 11 is reduced, the transistor 10 is activated and the transistor is turned on, thereby passing current through buzzer
12.

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