摘要:
A short arc lamp driving circuit includes a trigger boosting circuit, a flash current control circuit, and a closed loop exposure control and calibration circuits that, when combined, can produce short pulses of light with short time separation, quasi-continuous illumination light, and meanwhile, an extremely large dynamic range of delivered and/or calibrated light power or energy.
摘要:
A short arc lamp driving circuit includes a trigger boosting circuit, a flash current control circuit, and a closed loop exposure control and calibration circuits that, when combined, can produce short pulses of light with short time separation, quasi-continuous illumination light, and meanwhile, an extremely large dynamic range of delivered and/or calibrated light power or energy.
摘要:
For coupling one, or more, gaseous discharge lamps to a high-frequency AC power-source a ballasting (current-limiting) network employs a first capacitor, a second capacitor, and a transformer having a primary winding coupled to the high-frequency AC power-source by the first capacitor and a secondary winding coupled to the gaseous discharge lamp by the second capacitor.
摘要:
An improved power factor DC power supply in accordance with the present invention (100 or 200) employs a power factor correcting network (120), a full-wave rectifier means (122), a pair of filter capacitors (124 and 126), and three current steering diodes (128, 130 and 132). The power factor correcting network (120) includes both an inductor means (136 and 240) and a capacitor (138), the combination configured to improve the power factor DC power supply (100 or 200) presents to the AC power-line (102) by reducing the level of harmonic currents the DC power supply generates on the AC power-line. The filter capacitors (124 and 126) are configured with the current steering diodes (128, 130 and 132) such that the filter capacitors are charged in series and discharged in parallel. In addition, the filter capacitors (124 and 126) and the current steering diodes (128, 130 and 132) are configured such that during the periods when the level of the voltage being developed across the load (104) exceeds one-half the peak level, the improved power factor DC power supply (100 or 200) functions as though the filter capacitors were not in the circuit.
摘要:
A pair of transistors (110 and 112) configured with their channels connected in series. The gate of the "upper" transistor (110) is coupled to a relatively low-voltage, DC power supply voltage by a voltage-clamping and current-steering diode (144); to a relatively high-voltage, DC power supply voltage by the series combination of a current-steering diode (152) and one voltage-clamping zener diode (154 and 156) and coupled to the source of the "upper" transistor by a charge-removing resistor (162).
摘要:
For coupling one, or more, gaseous discharge lamps to a high-frequency AC power-source a ballasting (current-capacitor, and a transformer having a primary winding coupled to the high-frequency AC power-source by the first capacitor and a secondary winding coupled to the gaseous discharge lamp by the second capacitor.
摘要:
A single-ended ballast circuit employs a power-factor-correcting network (510); a DC power supply (512); a free-running oscillator (516); a transistor (518); a current-limiting (ballasting) network (520); and two fluorescent lamps (524). The transistor (518) is configured as a switch connected to be responsive to a signal generated (630) by the oscillator (516) and operative to periodically couple a line (734) to a circuit common. The current-limiting (ballasting) network (520) includes an inductor or transformer (740) having a primary winding (744), connected between a DC power-supply potential and the line (734), and a secondary winding (746); a first capacitor (750), connected between the line (734) and circuit common; an inductor (752); a second capacitor (756), connected in series with the inductor (752) across the secondary winding (746); and a third capacitor (754), connected in series with the lamps (524) across the second capacitor (756).
摘要:
For coupling one, or more, gaseous discharge lamps to a high-frequency AC power-source a ballasting (current-limiting) network employs a first capacitor, a second inductor, and a transformer having a primary winding coupled to the high-frequency AC power-source by the first capacitor and a secondary winding coupled to the gaseous discharge lamp by the second inductor.
摘要:
An electronic ballast for energizing one or more gaseous-discharge lamps and for regulating the power consumed thereby, the ballast including a power supply for providing a source of DC power between a pair of outputs, a pair of transistors connected as switches in series between the power-supply outputs, the transistors for selectively coupling to the juncture thereof positive and negative potentials, a voltage-conditioning and current-limiting network for energizing the lamp from the potential developed between the transistor juncture and a power-supply common, and a pulse generator for developing pulses for driving each of the transistors in turn whereby a potential is developed at the transistor juncture which alternates as positive-going and negative-going pulses each separated by a dead time, the pulse generator for monitoring the power consumption level of the lamp and responsive thereto operative to vary the frequency and/or the width of the transistor driving pulses whereby the lamp consumption is regulated. Also included is a third harmonic trap for coupling the power supply to the AC power line to improve the power factor.
摘要:
A telephone call diverting and answering system. The system includes a telephone call concentrator for diverting a telephone call placed at a telephone set at one of a number of calling stations, from a telephone line connected to the intended telephone set, at one of a large number of called stations, to one of a small number of telephone trunks leading to sets at a number of answering stations. The system further includes an operator console at each answering station, and a traffic director for assigning the call to a particular station by causing the identity of the called station and the number of the diverting trunk to be displayed on the operator console of the assigned answering station.