Abstract: Illuminated pushbutton switches are improved by replacing the traditional time delay relays, Boolean interface logic or driver components often incorporated within interface wiring and harnesses with a subminiature electronic logic module located within the illuminated pushbutton switch housing. This Logic Module provides numerous additional benefits beyond the standard illuminated push button switch by incorporating functional capability such as pulse timing, edge detecting or Boolean logic that allow the unit to replace external electro mechanical relays, diode logic, or time delay relays that are typical in current applications. These additional features provide enhancements by allowing lower size and weight, longer switch life, no electrical spikes, remote set and reset capability, display blinking, and high reliability electronic driver circuits that can drive modest electrical loads.

Abstract: Within an illuminating pushbutton switch, an electronic latching circuit replaces an electromagnetic holding coil for latching or releasing a state of the illuminated pushbutton switch. The electronic latching circuit includes inputs receiving clock and reset control signals, one or more outputs delivering latch output states, which may include multiple configurable states, and latch logic controlled by the clock and reset control signals and delivering signals maintaining the illuminated pushbutton switch in a predetermined condition depending upon the latch state. The electronic logic circuit fits within the illuminated pushbutton switch housing in space sized to hold one snap action switching device without increase in the length, weight or mounting depth of the illuminated pushbutton switch.

Abstract: A discrete dimming luminance control circuit for light emitting diode illumination includes first and second control inputs, a first supply circuit between the first control input and an output, a second supply circuit between the second control input and the output, a first shunt circuit between the second control input and the output, and a second shunt circuit between the first control input and the output. The luminance control circuit delivers a first voltage to the output when a supply voltage is applied to the first control input and the second control input is left open, a second voltage when the supply voltage is applied to the second control input and the first control input is left open, a third voltage when the supply voltage is applied to the first control input and the second control input is grounded, and a fourth voltage when the supply voltage is applied to the second control input and the first control input is grounded.

Abstract: Illuminated pushbutton switches are improved by replacing the traditional time delay relays, Boolean interface logic or driver components often incorporated within interface wiring and harnesses with a subminiature electronic logic module located within the illuminated pushbutton switch housing. This Logic Module provides numerous additional benefits beyond the standard illuminated push button switch by incorporating functional capability such as pulse timing, edge detecting or Boolean logic that allow the unit to replace external electro mechanical relays, diode logic, or time delay relays that are typical in current applications. These additional features provide enhancements by allowing lower size and weight, longer switch life, no electrical spikes, remote set and reset capability, display blinking, and high reliability electronic driver circuits that can drive modest electrical loads.

Abstract: Within an illuminating pushbutton switch, an electronic circuit replaces an electromagnetic holding coil for latching or releasing a state of the illuminated pushbutton switch, and further provides blinking functionality. The electronic circuit includes inputs receiving set, reset and toggle control signals, outputs delivering open, closed and blink control signals, latch logic controlled by the set and reset control signals and delivering signals maintaining the illuminated pushbutton switch in either an open or closed state, and a frequency divider and oscillator coupled together to deliver a blink control signal. The electronic circuit fits within the illuminated pushbutton switch housing in space sized to hold two snap action switching devices without increase in the length, weight or mounting depth of the illuminated pushbutton switch. The inputs and outputs are coupled to external pins from the illuminated pushbutton switch and may be remotely controlled.

Abstract: Within an illuminating pushbutton switch, an electronic latching circuit replaces an electromagnetic holding coil for latching or releasing a state of the illuminated pushbutton switch. The electronic latching circuit includes inputs receiving clock and reset control signals, one or more outputs delivering latch output states, which may include multiple configurable states, and latch logic controlled by the clock and reset control signals and delivering signals maintaining the illuminated pushbutton switch in a predetermined condition depending upon the latch state. The electronic logic circuit fits within the illuminated pushbutton switch housing in space sized to hold one snap action switching device without increase in the length, weight or mounting depth of the illuminated pushbutton switch.

Abstract: Each driver circuit for a six-by-four array of light emitting diodes illuminating a pushbutton switch switches three pairs of the light emitting diodes between series connection and parallel connection based on changes to an applied input voltage. Driving six light emitting diodes instead of only four allows illumination of a larger area and improves power efficiency at higher applied input voltages, while retaining dimming compatibility at low voltage levels. Each driver circuit also includes a rectifier allow illumination of the pushbutton switch with direct current voltages of either polarity. The quiescent current limiting resistance is split into multiple resistors for further improved power efficiency. Each driver circuit also includes a bridge rectifier to allow illumination of the pushbutton switch with direct current voltages of either polarity or alternating current voltages.

Abstract: Within an illuminating pushbutton switch, an electronic circuit replaces an electromagnetic holding coil for latching or releasing a state of the illuminated pushbutton switch, and further provides blinking functionality. The electronic circuit includes inputs receiving set, reset and toggle control signals, outputs delivering open, closed and blink control signals, latch logic controlled by the set and reset control signals and delivering signals maintaining the illuminated pushbutton switch in either an open or closed state, and a frequency divider and oscillator coupled together to deliver a blink control signal. The electronic circuit fits within the illuminated pushbutton switch housing in space sized to hold two snap action switching devices without increase in the length, weight or mounting depth of the illuminated pushbutton switch. The inputs and outputs are coupled to external pins from the illuminated pushbutton switch and may be remotely controlled.

Abstract: A discrete dimming luminance control circuit for light emitting diode illumination includes first and second control inputs, a first supply circuit between the first control input and an output, a second supply circuit between the second control input and the output, a first shunt circuit between the second control input and the output, and a second shunt circuit between the first control input and the output. The luminance control circuit delivers a first voltage to the output when a supply voltage is applied to the first control input and the second control input is left open, a second voltage when the supply voltage is applied to the second control input and the first control input is left open, a third voltage when the supply voltage is applied to the first control input and the second control input is grounded, and a fourth voltage when the supply voltage is applied to the second control input and the first control input is grounded.

Abstract: Each driver circuit for a six-by-four array of light emitting diodes illuminating a pushbutton switch switches three pairs of the light emitting diodes between series connection and parallel connection based on changes to an applied input voltage. Driving six light emitting diodes instead of only four allows illumination of a larger area and improves power efficiency at higher applied input voltages, while retaining dimming compatibility at low voltage levels. Each driver circuit also includes a rectifier allow illumination of the pushbutton switch with direct current voltages of either polarity. The quiescent current limiting resistance is split into multiple resistors for further improved power efficiency. Each driver circuit also includes a bridge rectifier to allow illumination of the pushbutton switch with direct current voltages of either polarity or alternating current voltages.

Abstract: Illumination color for a dedicated legend display area of an illuminated pushbutton switch may be programmed by controlling application of the driving voltage to one of two or more different groups of interleaved LEDs alternately illuminating the display area. Each of the different LED groups illuminates the display area with a different color, produced by different color LEDs, filtering of individual LEDs within each group, or dip-coating the LEDs. Application of the driving voltage to different switch input pins causes the legend to be illuminated by different LED groups in different colors, reflecting different conditions.

Abstract: Illumination color for a dedicated legend display area of an illuminated pushbutton switch may be programmed by controlling application of the driving voltage to one of two or more different groups of interleaved LEDs alternately illuminating the display area. Each of the different LED groups illuminates the display area with a different color, produced by different color LEDs, filtering of individual LEDs within each group, or dip-coating the LEDs. Application of the driving voltage to different switch input pins causes the legend to be illuminated by different LED groups in different colors, reflecting different conditions.

Abstract: Illumination sources, each including at least one light emitting diode, are connected either in series or in parallel by a switching circuit, depending upon an applied input voltage. The switching circuit switches the illumination sources from series- to parallel-connection, or vice versa, when the applied input voltage crosses a threshold value in traversing the operating range of applied input voltages. Because the light emitting diodes within the illumination sources are switched from series to parallel connection at a defined kickover point, the voltage-luminance characteristic changes on opposite sides of the kickover point. The resulting overall voltage-luminance characteristic has greater variability in luminance across the entire operating range of applied input voltages, and luminance-variance is not limited to only a portion of the operating range.

Abstract: Illumination sources, each including at least one light emitting diode, are connected either in series or in parallel by a switching circuit, depending upon an applied input voltage. The switching circuit switches the illumination sources from series- to parallel-connection, or vice versa, when the applied input voltage crosses a threshold value in traversing the operating range of applied input voltages. Because the light emitting diodes within the illumination sources are switched from series to parallel connection at a defined kickover point, the voltage-luminance characteristic changes on opposite sides of the kickover point. The resulting overall voltage-luminance characteristic has greater variability in luminance across the entire operating range of applied input voltages, and luminance-variance is not limited to only a portion of the operating range.

Abstract: Multi-color illumination for a single display is achieved by utilizing an array of white light emitting diodes to produce illumination optically filtered by separate filters to produce the two or more desired output illumination colors at a desired luminance when the full rated voltage is applied to the light emitting diodes. Since all of the light emitting diodes have the same bandgap, voltage-controlled dimming produces uniform luminance changes for all colors as the voltage is reduced. A single voltage-controlled dimming driver circuit design and a single control voltage may therefore be utilized to achieve desired and uniform dimming characteristics independent of output illumination color.

Abstract: A zener diode is connected in parallel with sets of series-connected light emitting diodes with a reverse forward bias orientation. The threshold voltage of the zener diode is matched to equal, or be just slightly greater than, the forward voltage drops for the light emitting diodes at maximum current. During normal operation, therefore, the zener diode draws virtually no current. Upon failure of one of the light emitting diodes, the zener diode conducts without increase in the applied voltage, providing an alternate current path maintaining circuit integrity so that other sets of light emitting diodes connected in series within the circuit continue to illuminate.

Abstract: To prevent inadvertent illumination of a light emitting diode (or set of light emitting diodes) by stray currents at extremely low levels, a quiescent current limiting resistive load is connected in parallel with the light emitting diode, sized to conduct a desired minimum current at the lowest forward voltage drop at which the light emitting diode is expected to properly illuminate. Rather than connecting the resistive load across the input/output ports of the driver circuit, in parallel with any biasing resistance and the light emitting diode, the load is connected directly in parallel with the light emitting diode. Additional current through the quiescent current limiting resistive load as the voltage across the input/output ports increase is thus effectively capped by the maximum forward voltage drop across the light emitting diodes.

Abstract: To prevent inadvertent illumination of a light emitting diode (or set of light emitting diodes) by stray currents at extremely low levels, a quiescent current limiting resistive load is connected in parallel with the light emitting diode, sized to conduct a desired minimum current at the lowest forward voltage drop at which the light emitting diode is expected to properly illuminate. Rather than connecting the resistive load across the input/output ports of the driver circuit, in parallel with any biasing resistance and the light emitting diode, the load is connected directly in parallel with the light emitting diode. Additional current through the quiescent current limiting resistive load as the voltage across the input/output ports increase is thus effectively capped by the maximum forward voltage drop across the light emitting diodes.

Abstract: Multi-color illumination for a single display is achieved by utilizing an array of white light emitting diodes to produce illumination optically filtered by separate filters to produce the two or more desired output illumination colors at a desired luminance when the full rated voltage is applied to the light emitting diodes. Since all of the light emitting diodes have the same bandgap, voltage-controlled dimming produces uniform luminance changes for all colors as the voltage is reduced. A single voltage-controlled dimming driver circuit design and a single control voltage may therefore be utilized to achieve desired and uniform dimming characteristics independent of output illumination color.

Abstract: Illumination sources, each including at least one light emitting diode, are connected either in series or in parallel by a switching circuit, depending upon an applied input voltage. The switching circuit switches the illumination sources from series- to parallel-connection, or vice versa, when the applied input voltage crosses a threshold value in traversing the operating range of applied input voltages. Because the light emitting diodes within the illumination sources are switched from series to parallel connection at a defined kickover point, the voltage-luminance characteristic changes on opposite sides of the kickover point. The resulting overall voltage-luminance characteristic has greater variability in luminance across the entire operating range of applied input voltages, and luminance-variance is not limited to only a portion of the operating range.