摘要:
A ballast controller integrated circuit which executes a specific set of instructions via an integrated state diagram architecture to control a fluorescent lamp or high intensity discharge lamp and protect the ballast. The state diagram architecture (Fig. 2) controls powering up and down of the IC (2) and the half-bridge circuit (6, 8) driven by the IC (2), preheating and striking of the lamp (4), running of the lamp (4), sensing for numerous possible fault conditions, and recovering from these fault conditions based on the normal maintenance of the lamp (4), while requiring fewer internal and external components than previous electronic ballasts.
摘要:
The invention relates to an electronic lamp ballast for operating at least one gas-discharge lamp (G1, G2). The electronic lamp ballast comprises a control circuit (IC2), which monitors a voltage potential applied to the input connection (NP) and, depending on the value of the voltage potential, operates the gas-discharge lamp (G1, G2) with or without preheating. The voltage potential monitored by the control circuit (IC2) can in particular depend on the charge status of an energy storage circuit (R22, C17) which is charged while the gas-discharge lamp (G1, G2) is operating and is discharged at a certain time constant when the electronic lamp ballast is switched off. This allows for dynamic switching between cold-start and warm-start operations.
摘要:
The invention relates to an electronic lamp ballast for operating gas-discharge lamps (G1, G2), where the electronic lamp ballast is controlled by means of a control circuit (IC2). The control circuit (IC2) controls the operation of the electronic lamp ballast in accordance with certain predetermined operating states (I - VIII) in which the control circuit (IC2) monitors certain status variables of the electronic lamp ballast or of a gas-discharge lamp (G1, G2) in accordance with the operating status. It changes from one operating status to a new operating status only if the status variables being monitored meet a condition assigned to the current operating status.
摘要:
The invention relates to a controller for a fluorescent lamp load, comprising DC-AC converter means (24) having an input and an output, DC supply means coupled to said input, output circuit means coupled to said output and arranged for coupling to said fluorescent lamp load (12), and control means (36) for controlling operation of said DC-AC converter and said DC supply means, said output circuit means including inductance means and resonant capacitor means forming a circuit (20) which is resonant at no-load and load-condition resonant frequencies with loads equivalent to those respectively obtained prior to and after lamp ignition. The control means (36) are arranged to operate in a lamp ignition phase to operate said converter at a frequency above the no-load resonant frequency of the output circuit means and to operate in an operating phase after lamp ignition to operate said converter in a frequency range above the load-condition resonant frequency of the output circuit means. The DC supply means comprise an up-converter (28) and the control means (36) include pulse width modulator means for applying high frequency gating pulses to said up-converter, which have a width so controlled as to maintain the DC output voltage of the DC supply means at a substantially constant level while also obtaining an input current wave form which is proportional to and in phase with the input voltage wave form. The control means include means for synchronizing the generation of said high frequency pulse width modulated gating pulses with a variable frequency signal applied to said DC-AC converter means.
摘要:
Ein Vorschaltgerät für eine Entladungslampe (L) enthält in üblicher Weise einen von einer Gleichspannungsquelle (B) gespeisten Wechselrichter (C), der die Wechelspannung für die Entladungslampe (L) erzeugt. Die Entladungslampe (L) liegt parallel zur Kapazität (C10) eines Serienresonanzkreises (L6/C10). Dem Wechselrichter (C) wird von einem variablen Frequenzgenerator (6,7,8,9,15,16) eine Wechselspannung variabler Frequenz zugeführt. Die Frequenz des variablen Frequenzgenerators ist von einer Steuereinheit (10) steuerbar. Der Steuereinheit werden Steuersignale zugeführt, die verschiedenen Parametern des Vorschaltgerätes entsprechen. Diese Parameter sind die Lampenspannung, der Lampenstrom, die Gleichstromleistung, die Gleichstromspannung, eine Niedervoltgleichspannung und der Phasenwinkel des Lastkreises (E) für den Wechselrichter (C). Die Reaktion der Steuereinheit (10) auf Veränderungen der erwähnten Parameter besteht in einer Veränderung der Frequenz des Frequenzgenerators oder in einem Abschalten des Frequenzgenerators oder des Wechselrichters (C).
摘要:
An electronic ballast circuit for fluorescent or other gaseous discharge lamps includes a resonant half-bridge inverter circuit. The source voltage to the inverter is a full-wave rectified line voltage together with a DC carry-over voltage for supplying power in the inter-cusp period of the rectified line voltage. A negative feedback circuit is responsive to lamp current to vary the inverter drive frequency and thereby regulate lamp current. The frequency response of the feedback loop is high enough and the gain-versus- frequency response of the inverter is such that lamp current and voltage are regulated to reduce the crest factor of lamp current to compensate for variation in the amplitude of the voltage across the semiconductor switches.