Supervised loop alarm radio transmitter system
First Claim
1. An alarm radio transmitter system which comprisesradio transmitter means for transmitting an alarm signal when energized,detector loop means for sensing alarm conditions,means defining a bridge circuit including said detector loop means in at least one arm thereof for unbalancing said bridge circuit when an alarm condition is sensed, andan electronic switch means for disconnecting operating power from said transmitter means and coupled to said bridge circuit means to energize said transmitter means only when said alarm condition is sensed.
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Accused Products
Abstract
In order to assure that an alarm signal is transmitted, whether in the case of a true alarm condition or tampering, whether advertent or inadvertent, without any significant increase in power requirements, an alarm radio transmitter system is provided with a supervised loop which controls an electronic switch for connecting the power source (a single battery) to energize the transmitter for a brief interval of time only when an alarm condition or tampering occurs. The supervised loop is part of a bridge circuit also connected to the power source which draws a minimum amount of current therefrom. The alarm radio transmitter system may be remotely located where attention is not available, since the battery need only be infrequently changed.
15 Citations
10 Claims
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1. An alarm radio transmitter system which comprises
radio transmitter means for transmitting an alarm signal when energized, detector loop means for sensing alarm conditions, means defining a bridge circuit including said detector loop means in at least one arm thereof for unbalancing said bridge circuit when an alarm condition is sensed, and an electronic switch means for disconnecting operating power from said transmitter means and coupled to said bridge circuit means to energize said transmitter means only when said alarm condition is sensed.
Specification