Abstract: A method for making a hard clear aligner set for stepwise orthodontic treatment is provided. The hard clear aligner set includes plural intermediate aligners made as follows. First, original tooth-row image files corresponding to a patient's teeth are obtained. Tooth arranging software is then used to produce final tooth-row image files by rearranging the teeth in the original tooth-row image files, define the displacements and rotation angles required for the patient's teeth in each step of the treatment, and after computation, produce plural stepwise tooth-row image files. Following that, dedicated software is used to define the surface thickness in each stepwise tooth-row image file, thereby producing shell-like aligner image files corresponding respectively to the intermediate aligners. The shell-like aligner image files are subsequently converted into digital control instructions in order to control a multiaxial carving machine to carve hard clear aligners from hard polymeric modular blocks.

Abstract: An LED bulb includes a lower cover having ventilation holes formed at outer periphery thereof, and a first coupling opening formed at top side thereof; a separating unit provided within the lower cover at a position between lower edges of the ventilation holes and bottom side of the lower cover, and having a convection pathway formed at top side thereof; a heat sink having bottom end positioned on top side of the separating unit; and an upper cover having top side formed with convection hole corresponding to top end of the heat sink, and a second coupling opening formed at bottom side thereof. When the second and first coupling openings are coupled with each other, the upper and lower covers are assembled together to form a central axis bidirectional convection heat dissipation pathway sequentially through the ventilation hole, the convection pathway, the heat sink and the ventilation hole accordingly.

Abstract: The present invention is to provide a minimalistic LED recessed light, which includes a light cup having a bottom provided with an opening and a top provided with a light-permeable hole in communication with the opening, a light chip having a bottom surface provided with at least one LED, a heat sink having a bottom connected with the top of the light cup for positioning the light chip therebetween and allowing the LED to correspond in position to the light-permeable hole, and an elastic supporting plate fixed to a top of the heat sink and having sections respectively and symmetrically bent toward the light cup and formed with an outwardly curved engaging surface, wherein the distance between the curved engaging surfaces is greater than a diameter of a fitting hole cut in a ceiling, for effectively achieving the objects of heat dissipation and easy installation/removal of the recessed light.

Abstract: An LED bulb includes a lower cover having ventilation holes formed at outer periphery thereof, and a first coupling opening formed at top side thereof; a separating unit provided within the lower cover at a position between lower edges of the ventilation holes and bottom side of the lower cover, and having a convection pathway formed at top side thereof; a heat sink having bottom end positioned on top side of the separating unit; and an upper cover having top side formed with convection hole corresponding to top end of the heat sink, and a second coupling opening formed at bottom side thereof. When the second and first coupling openings are coupled with each other, the upper and lower covers are assembled together to form a central axis bidirectional convection heat dissipation pathway sequentially through the ventilation hole, the convection pathway, the heat sink and the ventilation hole accordingly.

Abstract: The present invention is to provide a power converter, which includes a half-bridge circuit parallel-connected to an input voltage and having two series-connected power switches, an LLC resonant circuit formed by a resonant inductor, magnetic inductance of a primary winding and a resonant capacitor, a current-circulating circuit parallel-connected to the half-bridge circuit and having two series-connected rectifiers, and a full-wave rectification circuit connected to a secondary winding for generating an output voltage across an output capacitor. The LLC resonant circuit is parallel-connected to one of the power switches, and the line between the two rectifiers is cross-connected to the line between the resonant inductor and the primary winding.

Abstract: The present invention is to provide an electronic ballast connected in parallel to two filaments of a fluorescent light tube, which comprises a controller for generating two output signals, two power switches being switched according to the output signals, a resonant circuit oscillating according to switching of the power switches and thereby causing a resonant capacitor thereof to generate a voltage, a voltage sensor connected in series to the resonant capacitor and connected in parallel between the two filaments so as to sense an AC voltage proportional to a voltage across the fluorescent light tube, and a regulator connected separately to the voltage sensor and controller so as to convert the AC voltage into a DC voltage and deliver the DC voltage to the controller. Upon determining that the DC voltage exceeds a preset voltage level, the controller generates an interruption control signal for immediately stopping operation of the controller.

Abstract: The present invention is to provide a series resonant converter, which includes a transformer, two power switches connected to primary side of the transformer, a resonant control chip having two control pins connected to gates of the two power switches respectively, a resonant capacitor having one end connected to one end of the primary side and the other end connected to source of one power switch, a resonant inductor having one end connected to the other end of the primary side and the other end connected to a line between the two power switches, and at least one bypass resistor connected in parallel to the resonant capacitor, so as to allow voltage of the resonant capacitor to be rapidly released to ground when the converter is turned off and effectively lower inrush current of the resonant capacitor generated at an instant when the converter is turned on from off.

Abstract: The present invention is to provide a series resonant converter with an overload delay and short-circuit protection mechanism, which includes a voltage sensing circuit for sensing a voltage ripple level on a primary side of a transformer thereof, that corresponds to a load on a secondary side of the transformer, and generating and sending a DC detection level to an overload delay circuit and a short-circuit protection circuit thereof accordingly. The overload delay circuit and the short-circuit protection circuit are able control the converter through a resonant controller chip to output different currents according to magnitude of the load on the secondary side and maintain stable operation for a predetermined delay time even if the secondary side is overloaded, however, once the secondary side is short-circuited, the converter is turned off instantly. Thus, the converter is effectively prevented from damage which may otherwise result from sustained overload or short circuit.

Abstract: The present invention is to provide an electronic ballast connected in parallel to two filaments of a fluorescent light tube, which comprises a controller for generating two output signals, two power switches being switched according to the output signals, a resonant circuit oscillating according to switching of the power switches and thereby causing a resonant capacitor thereof to generate a voltage, a voltage sensor connected in series to the resonant capacitor and connected in parallel between the two filaments so as to sense an AC voltage proportional to a voltage across the fluorescent light tube, and a regulator connected separately to the voltage sensor and controller so as to convert the AC voltage into a DC voltage and deliver the DC voltage to the controller. Upon determining that the DC voltage exceeds a preset voltage level, the controller generates an interruption control signal for immediately stopping operation of the controller.

Abstract: The present invention is to provide a ballast circuit, which includes a preheat circuit configured to perform a fixed-time, fixed-frequency preheating process on filaments at both ends of a fluorescent light tube before it is lit. While the filaments are being preheated, a power driving circuit generates an output signal whose frequency is far higher than resonant frequency of a resonant circuit, and controls the preheat circuit for enabling a filament transformer and a high-frequency coupling capacitor in the preheat circuit to couple the voltage of the output signal to the filaments and thereby preheat the filaments, but not light up the light tube. When the preheat period is up, the power driving circuit stops the preheating process and changes the frequency of the output signal to a level close to the resonant frequency, thereby oscillating the resonant circuit and generating a high voltage enough for lighting the light tube.

Abstract: The present invention is to provide a constant-current circuit capable of voltage compensation and zero-voltage switching, wherein the constant-current circuit is a single-switch isolated flyback converter and includes a control circuit, a sensing resistor, a transformer, a voltage divider, and a primary-side power switch. The control circuit obtains information related to a primary-side current of the transformer by way of the sensing resistor and obtains a compensation signal from an input voltage by way of the voltage divider, so as to control the primary-side power switch accordingly. Due to a compensating effect of the compensation signal, a peak voltage resulting from the sensing resistor is adjusted to a reference voltage through adding the compensation signal thereto, thereby enabling the constant-current circuit to generate a constant output current over a wide range of input voltage.

Abstract: The present invention is to provide a ballast circuit, which includes a preheat circuit configured to perform a fixed-time, fixed-frequency preheating process on filaments at both ends of a fluorescent light tube before it is lit. While the filaments are being preheated, a power driving circuit generates an output signal whose frequency is far higher than resonant frequency of a resonant circuit, and controls the preheat circuit for enabling a filament transformer and a high-frequency coupling capacitor in the preheat circuit to couple the voltage of the output signal to the filaments and thereby preheat the filaments, but not light up the light tube. When the preheat period is up, the power driving circuit stops the preheating process and changes the frequency of the output signal to a level close to the resonant frequency, thereby oscillating the resonant circuit and generating a high voltage enough for lighting the light tube.

Abstract: The present invention is to provide a fluorescent lamp circuit capable of being easily repaired and repeatedly used even when one of filaments in a fluorescent light tube breaks because of age or defects, which will cause an electric arc between disconnected portions of the broken filament and generate a high resonant voltage and current in the resonant circuit. As soon as the resonant current flowing through a resonant capacitor exceeds an allowable current value of a circuit breaking element, the resonant current causes the circuit breaking element to form an open circuit, thereby promptly stopping the operation of the resonant circuit to prevent all the circuits and components in the fluorescent lamp circuit (except for the circuit breaking element) and plastic components that support the fluorescent light tube from burning which may otherwise result from an undue power demand of the resonant circuit and high heat generated by the electric arc.

Abstract: The present invention is to provide a series resonant converter, which includes a transformer, two power switches connected to primary side of the transformer, a resonant control chip having two control pins connected to gates of the two power switches respectively, a resonant capacitor having one end connected to one end of the primary side and the other end connected to source of one power switch, a resonant inductor having one end connected to the other end of the primary side and the other end connected to a line between the two power switches, and at least one bypass resistor connected in parallel to the resonant capacitor, so as to allow voltage of the resonant capacitor to be rapidly released to ground when the converter is turned off and effectively lower inrush current of the resonant capacitor generated at an instant when the converter is turned on from off.

Abstract: The present invention is to provide a recessed lamp support structure, which includes a lamp holder and at least two resilient plates. Each of the resilient plates has a front section fixedly connected to a sidewall of the lamp holder in a manner symmetrical to the others and a rear section extended away from the sidewall of the lamp holder, wherein the rear section has a roughened surface at a position away from the sidewall of the lamp holder. When the lamp holder is installed in a receiving hole of a ceiling, the roughened surfaces are able to press tightly and symmetrically against an inner periphery of the receiving hole due to the stress of the resilient plates, thereby securely positioning the lamp holder in the receiving hole while an annular frame of the lamp holder covers a gap between the receiving hole and the sidewall of the lamp holder.

Abstract: The present invention is to provide a recessed lamp support structure, which includes a lamp holder and at least two resilient plates. Each of the resilient plates has a front section fixedly connected to a sidewall of the lamp holder in a manner symmetrical to the others and a rear section extended away from the sidewall of the lamp holder, wherein the rear section has a roughened surface at a position away from the sidewall of the lamp holder. When the lamp holder is installed in a receiving hole of a ceiling, the roughened surfaces are able to press tightly and symmetrically against an inner periphery of the receiving hole due to the stress of the resilient plates, thereby securely positioning the lamp holder in the receiving hole while an annular frame of the lamp holder covers a gap between the receiving hole and the sidewall of the lamp holder.

Abstract: The present invention is to provide a constant-current circuit capable of voltage compensation and zero-voltage switching, wherein the constant-current circuit is a single-switch isolated flyback converter and includes a control circuit, a sensing resistor, a transformer, a voltage divider, and a primary-side power switch. The control circuit obtains information related to a primary-side current of the transformer by way of the sensing resistor and obtains a compensation signal from an input voltage by way of the voltage divider, so as to control the primary-side power switch accordingly. Due to a compensating effect of the compensation signal, a peak voltage resulting from the sensing resistor is adjusted to a reference voltage through adding the compensation signal thereto, thereby enabling the constant-current circuit to generate a constant output current over a wide range of input voltage.

Abstract: The present invention is to provide a heat dissipation housing for an LED lamp, which is made as a one-piece member by metal casting and formed with a receiving channel axially passing therethrough. A plurality of cooling fins axially are formed on an outer surface of the housing, wherein each said cooling fin is radially extended out of the housing and formed therein with a plurality of heat dissipation holes, and has two opposite sides with an included angle defined therebetween. Therefore, when an LED lamp installed on an end of the receiving channel starts to emit light, heat exchange between the LED lamp and the ambient cooling air outside the housing can be carried out through the cooling fins and the heat dissipation holes by both of thermal conduction and thermal convection, so as to effectively enhance the heat dissipation efficiency of the housing for the LED lamp.

Abstract: The present invention is to provide a series resonant converter with an overload delay and short-circuit protection mechanism, which includes a voltage sensing circuit for sensing a voltage ripple level on a primary side of a transformer thereof, that corresponds to a load on a secondary side of the transformer, and generating and sending a DC detection level to an overload delay circuit and a short-circuit protection circuit thereof accordingly. The overload delay circuit and the short-circuit protection circuit are able control the converter through a resonant controller chip to output different currents according to magnitude of the load on the secondary side and maintain stable operation for a predetermined delay time even if the secondary side is overloaded, however, once the secondary side is short-circuited, the converter is turned off instantly. Thus, the converter is effectively prevented from damage which may otherwise result from sustained overload or short circuit.

Abstract: The present invention is to provide an LED lamp, which comprises a heat dissipation housing formed with a receiving hole axially passed therethrough, an insulation housing, an electrode cap connected to the insulation housing, a power PCB, and an installation base plate having a first side installed with at least one LED. A manufacturer only needs to firstly insert the insulation housing along with the electrode cap into the receiving hole for allowing the electrode cap to be extended out of a lower end of the heat dissipation housing, then insert the power PCB into the insulation housing and electrically connect the power PCB to the electrode cap, and finally position a second side of the installation base plate on the upper end of the heat dissipation housing and electrically connect the installation base plate to the power PCB, so as to rapidly complete the installation of the LED lamp.