Abstract: A two-piece electronic siren apparatus including an integrated handheld microphone and control handle and a receiver/amplifier box is provided. The microphone and control handle permits handheld control of emergency light functions, siren functions, and auxiliary functions, as well as allowing a user to talk through a speaker. The integrated receiver/amplifier box includes both a siren board and a relay board. The siren board includes a microprocessor capable of generating siren tones and of controlling, among other things, a power amplifier located on the siren board, and auxiliary devices and functions. Additionally, the microprocessor controls two default modes of operation of the siren and/or light circuitry.

Abstract: A portable, self-contained, programmable electronic voting machine includes a motor-driven scroll mechanism carrying a plurality of printed ballot sheets, the scroll mechanism presenting to a voter, in a controlled manner, only a preselected portion of the ballot sheets at any one time. Each selected portion of the ballot sheets is viewed by a voter through a window panel along opposite vertical edges of which extend single columns of push-button switches positioned next to voter selections on the portion of the ballot sheets then being viewed. A voter depresses appropriate push-button switches to make vote selections. The voting selection process is repeated as the voter, by actuating the scroll mechanism, selects other portions of the ballot sheets. A voter then casts his vote using a separate vote casting switch.

Abstract: The invention is a control apparatus for use in an electronic siren circuit which generates a plurality of siren and intelligible audio outputs. The control apparatus includes a control module of relatively small size which may be mounted in a limited space proximate to an operator and a relatively larger, receiver module which may be mounted in any convenient location in a vehicle. The control module and remote receiver module are coupled together by a transmission line. Circuitry is provided in the control module and receiver module for producing binary coded control signals and for decoding these signals respectively to produce control signals in the receiver module. Circuitry is also provided for multiplexing intelligible audio signals over the same transmission line and for discriminating between the binary coded control signals and intelligible audio signals and conditioning the power module to reproduce same using the high power amplifier circuit of the siren.

Abstract: The invention is an electronic siren comprising in combination circuitry for generating one of a square wave siren and intelligible audio signal and a power output amplifier for audibly reproducing the signal. The amplifier includes transistor circuitry having base, emitter and collector means and a first circuit for coupling the signal-generating circuitry to the base means and one of said emitter and collector means for driving the transistors of the transistor circuitry into saturation in response to the siren signal. The first circuit includes circuitry for applying a dynamic biasing voltage derived from the siren signal to one of the emitter and collector means in phase with the voltage of the siren signal applied to the base means and of a plurality and opposition to the potential drop of the junction of the base means and the other of the emitter and collector means.

Abstract: A blowout preventing device is disclosed for attachment to vehicle wheels which have axially-elongated slots for receiving inner tube inflation stems. The device comprises a rigid filler piece which has a central portion for filling the slot and a circumferentially enlarged outer retainer portion which prevents radially inward displacement of the filler piece. An inner retainer means clamps the central portion to the inner face of the rim to prevent the device from falling into the tire in the event of deflation of the inner tube. Associated with the inner retainer means is a gripping means for engaging an inflation stem to prevent it from falling into the tire upon deflation.