Abstract: This present invention discloses a circuit of the electronic ballast with the capability of automatic restart. It includes a rectifier circuit, a trigger circuit of automatic restart, a DC/AC convertor, an output circuit of the lamp, and a circuit of abnormal protection. Its main feature is that there is a discharge loop in the trigger circuit, so it can realize automatic restart only after changing the lamp tube or connecting the lamp pin without turning off the power source when the lamp tube is abnormal and enters into protecting condition or any of the lamp pins is in poor contact. Because the trigger recourse Vt is led out from the lamp loop, when the power source is switched on, the DC/AC convertor is triggered to start after insuring good contact between the lamp tube and the lamp holder, accordingly realizes the self-check function of the connection for the lamp tube.

Abstract: This present invention discloses a circuit of the electronic ballast with the capability of automatic restart. It includes a rectifier circuit, a trigger circuit of automatic restart, a DC/AC convertor, a output circuit of the lamp, and a circuit of abnormal protection. Its main feature is that there is a discharge loop in the trigger circuit, so it can realize automatic restart only after changing the lamp tube or connecting the lamp pin without turning off the power source when the lamp tube is abnormal and enters into protecting condition or any of the lamp pins is in poor contact. Because the trigger recourse Vt is led out from the lamp loop, when the power source is switched on, the DC/AC convertor is triggered to start after insuring good contact between the lamp tube and the lamp holder, accordingly realizes the self-check function of the connection for the lamp tube.

Abstract: The present invention discloses a single-channel comprehensive protection circuit of a self-excitation half-bridge series resonant circuit having a single lamp output, including a DC block capacitor C3, a first partial pressure resistor R1, a second partial pressure resistor R2, a rectifying diode D1, a filter and integral capacitor C4, a release resistor R3, a diac D2, a filter capacitor C5, a filter resistor R4, wherein the method of one point of loading point A at the fluorescent lamp filament is used. The present invention normalizes the treatment of abnormal signals for over-current, over-voltage and end of lamp life state etc. in order to replace the conventional design of multi-channel and multi-point sampling for simplifying the circuit, reducing the cost and space, increasing reliability, and facilitating miniaturization development of the electronic lighting products.

Abstract: The present invention discloses a single-channel comprehensive protection circuit of a self-excitation half-bridge series resonant circuit having a single lamp output, including a DC block capacitor C3, a first partial pressure resistor R1, a second partial pressure resistor R2, a rectifying diode D1, a filter and integral capacitor C4, a release resistor R3, a diac D2, a filter capacitor C5, a filter resistor R4, wherein the method of one point of loading point A at the fluorescent lamp filament is used. The present invention normalizes the treatment of abnormal signals for over-current, over-voltage and end of lamp life state etc. in order to replace the conventional design of multi-channel and multi-point sampling for simplifying the circuit, reducing the cost and space, increasing reliability, and facilitating miniaturization development of the electronic lighting products.

Abstract: An ideal filament preheat technique in flourescence lamp is supplied by an adjusting circuit, an output circuit and a control circuit. At the filament preheating stage, an adequate preheating voltage is provided for the filament of the lamp tube, and the voltage cross over both ends of the lamp tube is reduced, thereby preventing glow current in preheating. When the preheating stage is finished and starting stage begins, the voltage between both ends of the lamp tube increases simultaneously, and then reaches a break-down voltage of the lamp tube, then the lamp tube is lit to enter a normal operation stage, the preheating voltage of the filament is cutoff under the control circuit, so as to save the filament power consumption. Therefore, the efficiency of the electronic ballast is improved, and the operation life of the flourescent lamp tube is extended.

Abstract: A fluorescent lamp end-of-life protection circuit in an illuminating electric appliance, includes a rectifying effect protection circuit for a lamp tube and an overvoltage protection circuit for the lamp tube, in which a circuitry of two series resistors and a capacitor in series is connected in parallel with the lamp tube. A cathode of a transient voltage suppresser is connected to one end of the lamp tube, its anode is connected to an anode of a diode, and a cathode of the diode is connected to a common node of two series resistors. One end of a trigger diode is connected to a common node of the capacitor and the resistor, and the other end thereof is connected to a gate terminal G of a triac, a first electrode and a second electrode of of which are connected to two ends of the lamp tube respectively.

Abstract: The present invention relates to a fluorescent lamp end-of-life protection circuit in an illuminating electric appliance. A need exists for a simple and all-sided protection circuit in view of hazard occurring at end of life of a lamp tube.

Abstract: An electronic ballast includes a power supply circuit comprising an electromagnetic compatible filter circuit, a rectifier circuit, a power factor correcting circuit, a DC filter circuit, and a DC/AC converter circuit connected successively, wherein: the electronic ballast further includes an adjusting circuit, an output circuit, and a control circuit. At a preheating stage, a preheating voltage is provided to the filament of the lamp tube, and the voltage applied between both ends of the lamp tube is reduced at the preheating stage, thereby preventing glow discharge in preheating from occurring. At a starting stage, the voltage between both ends of the lamp tube increases instantly, and reaches a break-down voltage of the lamp tube, at this time the lamp tube is lit, entering a normal operation stage and the preheating voltage of the filament is removed via the control circuit, so as to make the filament power consumption in conventional electronic ballast non-existent when the lamp tube operates normally.