Abstract: A stack light with a light section having a housing with a plurality of at least partially translucent side walls and having a plurality of opposing light sources on longitudinally opposite ends of the housing to produce a very even blended light. A stack light system with one or more such light sections also includes a sound section having a hollow housing and a set of interchangeable acoustic chambers configured for insertion into the hollow housing, each chamber including a piezoelectric transducer and having a side wall structure configured to abut an inner side wall surface of the hollow housing, the chamber, transducer and housing together defining a resonant cavity.

Abstract: A wireless tandem alarm having a first alarm configured for physical connection to an industrial machine having an electronic machine controller, and a second alarm configured for detachable connection to the first alarm or to the industrial machine. Each alarm has a housing, a piezoelectric transducer within the housing, a processor configured to drive the piezoelectric transducer in response to a control signal, and a wireless transceiver configured for relatively short-range, low-power communications. In the first alarm, the processor drives the piezoelectric transducer in response to a signal from the machine controller and, also responsive to the machine controller signal, transmits a control signal via the wireless transceiver. In the second alarm, the wireless transceiver receives the control signal from the first alarm and supplies it to the processor, which is configured drive the piezoelectric transducer in response.

Abstract: In further development of U.S. Pat. No. 6,310,540 B1, an audible signal device comprising of a microprocessor or microcontroller and a sounder element, or a microprocessor or microcontroller in conjunction with electronic circuitry such as discrete components, inductors, or IC's with a sounder element where the resulting sound pressure level is controlled by changing the drive signal's frequency, size, shape, and/or duty cycle.

Abstract: A panel-mountable audible and visual warning device comprising a main housing and a cap thereon, the device configured to have the main housing fit into a hole in the face of a mounting panel and to have the front wall and side wall of the cap external to the panel when the device is operably mounted therein, with the cap containing a piezoelectric transducer and at least one LED as a modular subassembly which is attached to the main housing. The cap and transducer together define an audio-frequency resonant cavity, and the cap has the LED(s) mounted therein in a position in front of the panel face in use and behind and radially outward of the transducer so as to emit light directly forward past the transducer.

Abstract: A wireless tandem alarm having a first alarm configured for physical connection to an industrial machine having an electronic machine controller, and a second alarm configured for detachable connection to the first alarm or to the industrial machine. Each alarm has a housing, a piezoelectric transducer within the housing, a processor configured to drive the piezoelectric transducer in response to a control signal, and a wireless transceiver configured for relatively short-range, low-power communications. In the first alarm, the processor drives the piezoelectric transducer in response to a signal from the machine controller and, also responsive to the machine controller signal, transmits a control signal via the wireless transceiver. In the second alarm, the wireless transceiver receives the control signal from the first alarm and supplies it to the processor, which is configured drive the piezoelectric transducer in response.

Abstract: A panel-mountable audible and visual warning device having an internal volume control shutter within a resonant cavity defined by the device housing and a sound generating element within the housing. Another embodiment has a cap on a main housing which fits into a hole in a mounting panel, with the cap external to the panel, the cap having multiple LEDs mounted therein in front of the panel face and behind and radially outward of a piezoelectric transducer so as to emit light directly forward past the transducer. Another cap embodiment has a piezoelectric transducer, LEDs, and a pushbutton switch mechanism including a movable surface portion of the cap's front wall and an internal set of switch contacts operably connected thereto. A control circuit can partially disable the alarm signaling function, such as by muting the transducer but continuing to energize the LEDs in response to actuation of the switch.

Abstract: In further development of U.S. Pat. No. 6,310,540 B1, an audible signal device including a microprocessor or microcontroller and a sounder element, or a microprocessor or microcontroller in conjunction with electronic circuitry such as discrete components, inductors, or IC's with a sounder element where the resulting sound pressure level is controlled by changing the drive signal's frequency, size, shape, and/or duty cycle.

Abstract: The invention is an improved audible signaling device with a speaker, a sound chamber, and associated circuitry. The device creates a loud, audible fundamental frequency, and harmonic frequencies that are relatively equal in amplitude to the amplitude of the fundamental frequency.

Abstract: In further development of U.S. Pat. No. 6,310,540 B1, an audible signal device comprising of a microprocessor or microcontroller and a sounder element, or a microprocessor or microcontroller in conjunction with electronic circuitry such as discrete components, inductors, or IC's with a sounder element where the resulting sound pressure level is controlled by changing the drive signal's frequency, size, shape, and/or duty cycle.

Abstract: The invention is an improved audible signaling device with a speaker, a sound chamber, and associated circuitry. The device creates a loud, audible fundamental frequency, and harmonic frequencies that are relatively equal in amplitude to the amplitude of the fundamental frequency.

Abstract: A dielectric fluid of refined soybean oil with additives of cycloaliphatic epoxide resin and butylated hydroxtolene covered in the winding of a metallized polypropylene film capacitor to prevent trapped air and moisture being absorbed in the winding.

Abstract: A piezoelectric transducer driving circuit has a main oscillator stage, a buffer circuit, and a voltage-doubling circuit. The main oscillator stage includes a frequency-swept signal generator that can be configured to provide different outputs to the buffers, which in turn provide the output to the voltage-doubling circuit, which supplies the piezoelectric transducer, causing it to mechanically deform and produce audible sounds of different types.