US 4,379,290 A · Alarm device with a condition sensor element

Abstract

In an alarm installation containing a central evaluation unit and alarm devices arranged remotely therefrom, the transmission of energy from a radiation source and the reporting back of the signal occurs exclusively according to optical principles by means of radiation conducting elements, so-called light guides or conductors, by means of which the alarm devices are connected with the evaluation device. The alarm devices contain a preferably high-ohm sensor element, for instance a smoke-sensitive ionization chamber, whose operating voltage is infed by means of a solar cell which is irradiated by a light guide and whose output signal is fed back to the evaluation device by means of a high-ohm electrical transducer and a light guide. Such type alarm installation preferably is used for fire detection purposes, for gas, smoke temperature detection or intrusion protection, and is particularly suitable for use in an explosion-endangered environment or one subjected to electrical disturbances.

Claims20

Dependent claims

An alarm device comprising:

a condition sensor element for delivering an output voltage which upon occurrence of a condition which is to be reported alters said output voltage in order to initiate giving of an alarm signal;
an opto-electrical transducer operatively connected with said sensor element for applying an electrical potential thereto;
at least one radiation-conducting element for transmitting electromagnetic radiation to said opto-electrical transducer in order to thereby deliver said electrical potential for the voltage supply of the sensor element;
an electro-optical transducer operatively connected with said sensor element;
an input radiation-conducting element for infeeding electromagnetic radiation to said electro-optical transducer;
an output radiation-conducting element for outfeeding electromagnetic radiation from the electro-optical transducer;
and
said electro-optical transducer modulating, in response to said sensor element, the electromagnetic radiation passing from said input radiation-conducting element to said output radiation-conducting element.

5 more elements

Dependencies are inferred from the claim text.

Alarm device with a condition sensor element

Life of this patent

Alarm device with a condition sensor element

Life of this patent

Abstract

Claims20