摘要:
A metal halide lamp, having a cold fill pressure of at least 50 torr, incorporates a starter circuit with an active device to protect the diode included therein. The active portion of the starter circuit, either removes a voltage multiplying circuit portion, from the starter circuit or shorts out the diode by shunting action of the switch. The voltage multiplier circuit portion is connected across the main electrodes, wherein the voltage multiplier circuit portion increases the starting voltage applied to the starter electrode.
摘要:
A high intensity discharge lamp system includes an AC supply for a chamber within which a plasma conductor is created to generate light. In order to confine charged particles within the chamber and to inhibit migration and loss thereof, a DC circuit taps power from the AC supply and produces a DC potential which is applied to relatively large-surface components in the vicinity of the plasma chamber. Properly polarized, the large-surface components, such as a reflector and a conductive housing, refractor or door, produces electric fields which inhibit migration of the charged particles. The result is improved color and light output as well as increased lamp life.
摘要:
A cold-cathode fluorescent discharge tube has a pair of electrodes for performing discharge between the electrodes in response to the application of a voltage therebetween. The fluorescent discharge tube of the invention includes an auxiliary electrode provided in the vicinity of one of the pair of electrodes, and a unit for applying the voltage between the pair of electrodes and between the auxiliary electrode and the one of the electrodes. With the auxiliary electrode, a discharge is firstly started between the auxiliary electrode and the one of the electrodes in response to the application of the voltage between the pair of electrodes. Thereafter, a discharge is started between the pair of electrodes. Thus, the start discharge is generated in the discharge tube in a relatively short period of time even if the discharge tube is set in the off state for a long time, particularly in the dark at a low temperature.
摘要:
A circuit arrangement for starting and operating gas discharge lamps with current of higher frequency comprises an electronic ballast unit connected to a direct voltage input source (2). An electronic switching element (3), which is controlled by a control device (8), is connected in series with an inductive element (4), and the discharge lamp (5). The lamp current flows through the inductive element from which a voltage is derived which is supplied to the control device as a supply direct voltage supply via a rectifier (14) and a smoothing capacitor (16). A first connection terminal of the smoothing capacitor is connected through a first ohmic resistor (18) to a first terminal of the direct voltage input source and a second connection of the capacitor is connected through the lamp (5) to a second terminal of the direct voltage input source.
摘要:
A method of reliably operating flashlamps with most of the stored energy charged to a voltage below the minimum specified electrode voltage is also disclosed. The flashlamp discharge control method allows reliable operation of the same variable voltage energy storage capacitors with more than a ten-to-one selectable variation of lamp Effective Candella Power for visual signalling. The disclosed dynamic impedance matching method matches the energy storage capacitors to the lamp after the three terminal flashlamp is triggered to its manufacturers' specified "on" state in the conventional fashion. When the lamp's main discharge voltage becomes lower than the voltage of the more principal energy storage capacitors, discharge of those capacitors is begun, usually through a semi-conductor rectifier operated within its integrated limits. The more principal energy storage capacitors may be charged with constant energy rather than at constant voltage, so that, for a constant Effective Candella Power, varying capacitances such as are found in electrolytic capacitors may be used with significant savings in size, weight and cost.
摘要:
Unitary light source comprises compact HID lamp and starting and operating circuit therefor operable from household AC energizing potential. The HID lamp is ballasted by incandescent filament means which also provides the major portion of developed light during HID warm up and after power interruption. The ballast filament and input terminals of a full-wave rectifier connect in series across the light source input terminals and the HID lamp connects across the rectifier output. A low-impedance path means and high-voltage pulse generator, which includes a high-voltage electrode operatively associated with the HID lamp, connect across the rectifier input. Initially, the voltage developed across the rectifier input is relatively high and the pulse generator and low-impedance path means are responsive thereto to devleop high voltage pulses and also provide a low impedance path in series with the ballast filament to cause it to incandesce brightly. The developed high voltage pulses applied to the high voltage electrode ionize the atmosphere within the HID envelope. After the HID lamp starts, the voltage develped across the rectifier input is insufficient to energize the low-impedance path means and pulse generating means. As the HID lamp warms up, the brightness of the incandescent ballast filament means decreases. A lamp keep-alive comprising a DC source is connected across the rectifier means output terminals to provide lamp operating energy during periods of rectifier conduction minima and, if necessary, to provide DC energy as a lamp starting aid.
摘要:
A power supply, including a static inverter, which is suited for the periodic energization of a flash tube. The static inverter may be turned off during periods when a capacitive load charged thereby is being discharged through the flash tube. The power supply has the capability of causing two successive ionizations of a flash tube within a short time period and may include both over-current and over-voltage protection in the form of sensing circuits which disable the static inverter.
摘要:
The invention relates to a mixed light lamp arrangement intended to be connected to an a.c. power supply. The lamp arrangement comprises a rectifier bridge having output terminals interconnected by the mixed light combination consisting of a series arrangement of an incandescent filament and a discharge tube. The series arrangement is shunted by a branch comprising a capacitor and an anti-parallel arrangement of a diode and a thyristor with the thyristor being rendered conductive just prior to the end of each half cycle of the a.c. power supply. This results in a mixed light lamp wherein the capacitance of the capacitor can have a relatively low value and the luminous efficacy can be relatively high.
摘要:
A ballast circuit for a fluorescent bulb comprises a voltage quadrupler circuit in series with a ballast resistor and the bulb. The quadrupler circuit comprises a voltage doubler circuit whose output voltage is doubled by a second voltage doubler circuit. The first voltage doubler circuit includes a first pair of series capacitors capable of supplying lamp current at operating voltage. The second voltage doubler circuit comprises a pair of series capacitors for providing full quadrupler voltage for no-load triggering but negligible effect under load and have a capacitance that is much smaller than the capacitance of the first doubler capacitors. A variable resistance in series with the first voltage doubler circuit may function as a dimmer control.