Abstract: A dock clamp employed in combination with a dock support structure that supports a dock section at an adjusted height by means of post members that are slidable within corresponding sleeve members attached to the dock section, the dock clamp serving to provide a fixed frictional coupling between a pair of corresponding post and sleeve members. The dock clamp includes a pair of rigid pieces each having an open end and a pronged end with a tapered configuration that is wedged between corresponding post and sleeve members at opposing ends and at one side of the sleeve member for applying a radial force in a direction that drives said post and sleeve members together at the side opposite to said one side in response to an applied axial force. The dock clamp further includes fastener means for applying an axial force by forcing facing open ends of said pair of rigid pieces toward one another.
Abstract: A capacitive touch panel comprising an array of touch sensitive switch cells, the panel including relatively small area touch switch elements located on closely spaced centers, that can be of transparent construction particularly suited for use with data processing equipment and electronic displays. Each switch cell includes a first and a second pair of series connected capacitors energized by a common signal source, the array of switch cells being arranged so that the first pair of capacitors are connected in first groups of switch cells, such as rows, to a corresponding first plurality of signal detectors, and the second pair of capacitors are connected in second groups of switch cells, such as columns, to a corresponding second plurality of signal detectors, the junctions of each pair of capacitors of a single switch cell being selectively coupled to ground by the body or other touch capacitive means for actuating a selected switch cell.
Type:
Grant
Filed:
October 30, 1978
Date of Patent:
November 11, 1980
Assignee:
General Electric Company
Inventors:
William L. Grummer, Hendrik B. Hendriks
Abstract: An audible indicator circuit including a piezoelectric crystal and transistor device, that is of extremely simple and inexpensive construction and has its on-off operation selectively controlled in response to an automatic or manually applied control signal. The piezoelectric crystal is connected between the collector and emitter electrodes of the transistor, so that with an "on" control signal applied to the base electrode and a supply voltage of magnitude that exceeds the collector to emitter breakdown voltage coupled to the collector electrode, the circuit is caused to oscillate and thereby emit an audible signal.
Abstract: A brightness control circuit for use with light emitting (LED) displays, or comparable electronic displays that are energized from a source of DC potential that supplies periodic pulses of constant peak current to the display elements, the display brightness being controlled as a function of the pulse duty cycle so as to achieve a uniform and continuous control of the display over a relatively wide range of brightness levels, extending particularly into the lower brightness region. Energizing current is coupled to the display by a transistor switching means actuated at a given frequency and with a duty cycle that is a function of the brightness control setting.
Abstract: An inexpensive DC power supply including a primary DC voltage source generating a voltage with an inherent ripple content that is coupled to energy receiving circuitry by an emitter follower switching circuit under the control of a secondary DC voltage source of relatively constant voltage amplitude, so as to apply to said energy receiving circuitry a voltage with the constant amplitude characteristics of the secondary voltage source and at relatively high current levels which are generated by the primary voltage source. By adjusting the magnitude of the secondary voltage applied to the emitter follower circuit, ripple may be substantially eliminated from the voltage applied to the energy receiving circuitry by virtue of this applied voltage being established below the ripple component of the primary DC voltage.
Abstract: An audio amplifier is described designed for integrated circuit fabrication and having controlled idling current. The amplifier includes a pre-amplifier designed to be driven from an AM or FM detector or a high impedance ceramic cartridge. The powder amplifier has a pair of like conductivity type output transistors connected in push-pull and driven by a novel interstage driver whose circuit configuration and component parameters are selected to reduce the idling current to a small predictable value. Measures are further provided, including two feedback paths, for insuring stability, minimizing distortion and hum. The amplifier is executed in an integrated circuit format with a minimum of outboarded components and a minimum "pad" requirement.