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US 4,363,028 AGranted
Electronic siren
AssigneeWhelen Engineering Company, Inc.
InventorJohn J. Bosnak
Life of this patent
Estimating the term…
Abstract
An electronic siren-public address system with remote control capability. The siren-public address system employs a push-pull power amplifier wherein the output transistors are driven into saturation in the siren mode to minimize power dissipation in the power amplifier.
Claims12
Apparatus for generating an electrical signal which varies at an audible frequency comprising:
- controllable oscillator means;
- remote control means, said remote control means including a mode selector switch and encoder means for generating a binary coded output signal commensurate with the setting of said mode selector switch;
- decoder means, said decoder means being located remotely from said remote control means and being responsive to the coded output of said remote control means for generating a plurality of gate control signals;
- means delivering the coded output of said remote control means to said decoder means;
- gate circuit means responsive to the control signals generated by said decoder means, said gate circuit means including switch means connected to said oscillator means, said gate circuit means changing the frequency and rate of change of frequency of said oscillator means output signal commensurate with the setting of said remote control means mode selector switch;
- amplifier means;
- means applying said oscillator means output signals as the input signal to said amplifier means;
- and
- means for delivering signals amplified by said amplifier means to a loudspeaker.
6 more elements
Dependencies are inferred from the claim text.