Abstract: A power factor correction (PFC) circuit includes an adaptive multiplier feedback control circuit to enhance stability of the PFC circuit for high input voltage and low input power (i.e., low input current) conditions. The adaptive multiplier feedback control circuit controls a voltage provided to a multiplier voltage input of a controller of the PFC circuit. The controller determines control loop gain as a function of the voltage at the multiplier voltage input terminal of the controller. The adaptive multiplier feedback control circuit increases the voltage at the multiplier voltage input of the controller is the input current to the PFC circuit increases. The PFC circuit may be used in an AC to DC converter of the driver circuit of a light fixture operable to provide power to a light source of the light fixture.

Abstract: Conditioning circuits are provided for driving two or more LED groups using a rectified AC input voltage. The conditioning circuits uses analog circuitry to gradually and selectively activate the LED groups based on an instantaneous value of the rectified input voltage. The circuit includes a first series interconnection of a first LED group, a first transistor, and a first resistor, and a second series interconnection of a second LED group, a second transistor, and a second resistor. In one example, the second series interconnection is connected between a drain terminal and a source terminal of the first transistor, while in another example, the second series interconnection is connected between an anode of the first LED group and a source terminal of the first transistor. The first and second LED groups are selectively activated by the rectified voltage applied across the first series interconnection.

Abstract: Provided is a method of detecting a state of a power cable in an inverter system. The method includes detecting a direct current (DC)-link voltage value of a DC-link capacitor included in an inverter, detecting a battery voltage value of a battery supplying a DC power to the inverter, comparing the DC-link voltage value with the battery voltage value, and determining the state of the power cable connecting the inverter to the battery to be abnormal when a difference between the DC-link voltage value and the battery voltage value is out of a preset range.

Abstract: This relates to a current limiter circuit that can be used in a power conversion system having a triac dimmer. In one example, the power conversion system may be used in an off-line LED driver. The current limiter circuit may be coupled to a power converter of the power conversion system and may operate to reduce the current that the power converter receives from an input line in the event of a power line surge. The current limiter circuit may also be coupled to the triac dimmer and may also operate as a damper for a portion of the half line cycle. The current limiter circuit may dampen the ringing in the triac current for a portion of the half line cycle and may cease dampening for the remaining portion of the half line cycle.

Abstract: A Light Emitting Diode (LED) driving circuit includes a reference-voltage terminal, an input terminal to receive a pulse-width modulated (PWM) power signal, and a PWM output terminal. An LED is coupled across the PWM output terminal and the reference-voltage terminal. A measurement capacitor circuit and a voltage-divider network are coupled in parallel with the LED. During an interruption of the PWM power signal, a sense node of the voltage-divider provides a voltage indicative of a temperature of the LED prior to the interruption. The voltage indicative of the temperature is used to control driving of the LED.

Abstract: A lighting device for lighting a solid light-emitting element includes: a DC power source circuit configured to output DC power; a power conversion circuit including a semiconductor element connected between output terminals of the DC power source circuit, the power conversion circuit configured to supply power to the solid light-emitting element through a control of a conduction state of the semiconductor element; a first control circuit configured to control an output of the DC power source circuit; a second control circuit configured to control an output of the power conversion circuit by controlling the conduction state of the semiconductor element; and a short-circuit detection circuit configured to detect a short-circuit in the semiconductor element. The first control circuit reduces the output of the DC power source circuit when the short-circuit detection circuit detects the short-circuit in the semiconductor element.

Abstract: Conditioning circuits are provided for driving two or more LED groups using a rectified AC input voltage. The conditioning circuits uses analog circuitry to gradually and selectively activate the LED groups based on an instantaneous value of the rectified input voltage. The circuit includes a first series interconnection of a first LED group, a first transistor, and a first resistor, and a second series interconnection of a second LED group, a second transistor, and a second resistor. In one example, the second series interconnection is connected between a drain terminal and a source terminal of the first transistor, while in another example, the second series interconnection is connected between an anode of the first LED group and a source terminal of the first transistor. The first and second LED groups are selectively activated by the rectified voltage applied across the first series interconnection.

Abstract: Conditioning circuits are provided for driving two or more LED groups using a rectified AC input voltage. The conditioning circuits uses analog circuitry to gradually and selectively activate the LED groups based on an instantaneous value of the rectified input voltage. The circuit includes a first series interconnection of a first LED group, a first transistor, and a first resistor, and a second series interconnection of a second LED group, a second transistor, and a second resistor. In one example, the second series interconnection is connected between a drain terminal and a source terminal of the first transistor, while in another example, the second series interconnection is connected between an anode of the first LED group and a source terminal of the first transistor. The first and second LED groups are selectively activated by the rectified voltage applied across the first series interconnection.

Abstract: Techniques for high temperature ultra-low ripple multi-stage LED driver circuit together with LED control circuits are disclosed.

Abstract: An LED drive circuit includes: a rectifier circuit that outputs a full-wave rectification waveform voltage; a primary LED row that includes a first partial LED row and a second partial LED row; an auxiliary LED row; a bypass circuit that is connected to part connecting the first partial LED row and the second partial LED row and that returns current from the first partial LED row to the rectifier circuit; and a current limiting circuit that limits the current flowing through the auxiliary LED row wherein the primary LED row and the auxiliary LED row are connected in parallel to the rectifier circuit; and the bypass circuit blocks the current passing through the bypass circuit in accordance with the current flowing through the primary LED row, and controls and blocks the current flowing through the auxiliary LED row.

Abstract: Systems and methods are provided for managing switching operation of a power converter, for example and without limitation, for powering LEDs in an efficient manner. According to one aspect, a system for managing a switching operation of a power converter includes an off time control system for managing operation modes of a power converter. The off time control system includes an active device for transmitting a bias signal, where the bias signal is configured for modulating a zero diode current signal for controlling a trigger signal, and a resistive body for discharging the bias signal.

Abstract: A lighting module includes a power line for receiving a power supply current and a ground line, a segmentation point for cutting the lighting module into two parts, a first set of light sources upstream of the segmentation point, a second set of light sources downstream of the segmentation point, wherein the first and second sets of light sources are connected in series, and a resistive element connected to the intermediate point between the first and the second set of light sources, and the ground line, which is configured in such a way that: when the lighting module has not been cut, the resistive element has a resistance which is greater than the resistance of the portion of the lighting module downstream of the segmentation point, and when the lighting module has been cut, the resistive element has a resistance which is less than the resistance thereof.

Abstract: Various embodiments relate to a lighting module. The lighting module includes at least one light source, regulating means for regulating the brightness of the light emitted by the at least one light source, and a control unit configured for receiving a brightness control signal, and driving the regulation means as a function of the brightness control signal, wherein the control unit is configured for: verifying whether the brightness control signal contains a digital communication signal, and if the brightness control signal includes a digital communication signal, detecting the data transmitted via the digital communication signal and driving the regulating means as a function of the transmitted data, or if the brightness control signal does not includes a digital communication signal, driving the regulating means as a function of the brightness control signal.

Abstract: An aircraft heating system (100) is provided which can be supplied with DC power from an onboard source (130). The system (100) comprises a heater (150) positioned to provide heat to an aircraft appliance (101), a sensor (160) situated to sense appliance-relevant temperatures, a reporter (170) reporting system faults, and an introducer (180) introducing temperature setpoints. A thermostat (200) integrates circuitries which together manage power supply, control heating, convey sensed temperatures, detect heater and/or sensor faults, and/or perform other advantageous functions.

Abstract: A semiconductor component and a method for manufacturing the semiconductor component, wherein the semiconductor component includes one or more transient voltage suppression structures. In an embodiment, the semiconductor component may include an over-voltage detection circuit, an over-current detection circuit, an over-temperature detection circuit, an ESD protection circuit, or combinations of these circuits.

Abstract: There is provided an output circuit for supplying an output current to a load coupled to an output terminal in response to an input signal. The output circuit includes an output transistor for supplying the output current to the output terminal, an output-drive circuit for driving the output transistor, a constant-current limiting circuit for generating a current control signal for limiting the output current to a predetermined current value, and a control circuit for implementing a control such that the output current is controlled on the basis of the current control signal if a voltage at the output terminal is at a predetermined voltage, or less after the input signal is supplied while the output transistor is driven by the output-drive circuit if the voltage at the output terminal is in excess of the predetermined voltage.

Abstract: The present invention provides a light emitting diode (LED) driving device, which comprises: a direct current/direct current (DC/DC) controller, for controlling an output segment that is used to generate an output voltage from an input voltage and supply the output voltage to an LED; an output current driver, for generating an output current of the LED; and an output discharging circuit, for performing, based on a predetermined control signal, discharging of the output voltage when a generation action of the output voltage and the output current stops.

Abstract: A power supply circuit (4) is responsive to an activating signal by supplying a discharge lamp (2) with an operating voltage on which a high voltage is temporality superposed. An insufficient current detecting circuit (46) detects abnormality of an output current supplied to the discharge lamp (2) from the power supply circuit (4). A CPU (52) stops the operation of the power supply circuit (4) in response to detection of abnormality by the insufficient current detecting circuit (46). An output nullification time period timer (50) nullifies the output of the insufficient current detecting circuit (46) for a predetermined time period measured from the supplying of the activating signal.

Abstract: Systems and methods for detecting an incorrect load and preventing powering of that load, until a load change is detected, are disclosed. An incorrect load can be removed and a newly attached valid load can be operated without requiring a reset. A power supply or driver system for a lighting system including one or more solid state light sources includes the systems and methods. The power supply or driver system includes a processor and memory arrangement configured to detect whether a load is operable or non-operable while still being responsive to a new load being attached at any time, and to prevent the system from checking the same load more than once. These may be used in conjunction with features like auto-recovery, restart after faults, and load-hot-plug capability, while perhaps simultaneously reducing cyclical flashing of light output.

Abstract: A driving circuit with an over-voltage protection device for modulating an electrical parameter of a driven device includes at least a boost circuit, a signal processing circuit, an over-voltage protection device, a modulation device and a control circuit. The output terminal of the boost circuit is electrically coupled in series to a driven device, a transistor and a grounded feedback resistor sequentially, wherein the output terminal of the boost circuit is further electrically coupled to a voltage dividing circuit for outputting a voltage dividing signal. The signal processing circuit is provided for outputting a processing signal to the over-voltage protection device and the modulation device according to the voltage dividing signal and a modulation signal. The control circuit is provided for turning on the transistor or not according to an output signal of the over-voltage protection device and an output signal of the modulation device.

Abstract: When a pulsating current is applied to an LED string included in an LED lighting device, and the number of LEDs caused to light up is changed, the LED lighting device is in efficient, since there are LEDs lighting up for a long period of time and LEDs lighting up only for a short period of time. The LED string includes LED string 407 that lights up for a long period of time and LED string 408 that lights up only for a short period of time within a period of the pulsating current. The element size of the LED 102 included in LED string 407 is different from the element size of LED 203 string 408. Thus, the amount of light emission per unit area LED string 407 may be equal to the amount of light emission per unit area LED string 408.

Abstract: Disclosed herein are apparatus, methods, and systems for assessing the life span of a product and/or system—particularly with respect to end-of-life conditions which are defined by a customer, owner, operator, or other person(s) associated with the product and/or system—and communicating the assessment to said customer, owner, operator, or other person(s). According to one aspect, end-of-life conditions are defined in terms of product life (e.g., anything that relates to how well and how long the product/system operates) and/or economic life (e.g., anything that relates to the cost of deriving a benefit from the product/system). In one particular example, the products or systems relate to lighting systems, particularly those utilizing LED (or other solid-state) light sources.

Abstract: According to one embodiment, there is provided a power supply device includes a DC-DC converter and a protection circuit. The DC-DC converter includes a switching element of a normally on type, a current control element of the normally on type connected to the switching element in series and configured to control an electric current flowing to the switching element, and a rectifying element connected to the current control element in series. The DC-DC converter converts, according to ON and OFF of the switching element, an input first direct-current voltage into a second-direct current voltage, which has an absolute value different from an absolute value of the first direct-current voltage, and supplies the second direct-current voltage to a load. When an electric current equal to or larger than a predetermined value flows to the switching element and the current control element, the protection circuit cuts off the electric current.

Abstract: The present application discloses a LED driver including: a first and a second auxiliary windings connected in series with each other; a first rectifying device coupled with a terminal of the first auxiliary winding while the other terminal is coupled with the second auxiliary winding; a second rectifying device coupled with a terminal of the second auxiliary winding; a first voltage regulator coupled with the first rectifying device; an unidirectional conducting device having a positive and a negative terminals; and a DC output terminal coupled with the negative terminal of the unidirectional conducting device and configured to provide required DC electricity to a control circuit in the LED driver. The LED driver can guarantee that Vcc voltages provided under a heavy or light load state can always meet the DC power supplying requirements of respective control devices in the driver and meanwhile losses can be reduced.

Abstract: A lighting apparatus for a fluorescent tube and a driving method thereof are provided. The lighting apparatus includes a fluorescent tube, an open-loop protection unit and a driving device. The driving device includes an inverter and a power unit. The open-loop protection unit detects and determines an open-loop situation of two nodes of the fluorescent tube to produce an open-loop protection signal. The inverter receives a power voltage to light the fluorescent tube with a dual high-voltage method according to a trigger signal. The power unit coupled to the open-loop protection unit and the inverter provides the power voltage and determines whether to turn off the inverter according to the open-loop protection signal. When the open-loop situation of the fluorescent tube is occurred or driving voltage of the fluorescent tube is greater than a rated operating voltage, the inverter is turned off immediately to avoid components from overheating or burning.

Abstract: A driving apparatus configured to drive a light emitting device includes a driving current source module operable to supply current to the light emitting device via a node during operation. A protection module coupled to the node and the driving current source module selectively injects current to the node during operation. The driving current source module is controlled based on a detection result of a voltage on the node.

Abstract: The present invention has been made in an effort to provide an organic light emitting display device comprising a panel; a power supply supplying power to the panel; a current detection unit detecting a current flowing through power line wiring of the panel and outputting the detected current; and a power controller comparing the detected current with a current value configured internally and outputting a shutdown signal which turns off the power supply if the detected current exceeds the predetermined current value.

Abstract: Described herein is a circuit and method for independent control of series connected light emitting diodes (LEDs). The circuit includes a first light emitting diode (LED) connected in series with a second LED. A current source is connected in series with the first LED and the second LED and a shunt circuit is connected in parallel with the first LED and the second LED. The shunt circuit includes a pair of serially connected resistors. The shunt circuit prevents inadvertent excitement of the LEDs due to leakage currents but minimally affect illumination characteristics of the LEDs. A pair of transistors is connected to the first LED and the second LED, respectively, and is biased using a set of bias resistors. A tri-state control signal switches on and off the pair of transistors and enables excitation of the first LED, the second LED or both via the current source.

Abstract: A light emitting diode (LED) driving circuit structure includes a surge absorber unit, a voltage suppression unit connected to the surge absorber unit, a rectifier unit electrically connected to the voltage suppression unit, a control chip connected to a fourth junction of the rectifier unit, and an impedance unit connected to the control chip. The LED driving circuit structure is installed on an LED light circuit board having a plurality of LEDs mounted thereon. According to the sinusoidal wave form of the alternating current (AC) supplied to the LEDs as well as the number and layout of the LEDs on the LED light circuit board, the LED driving circuit structure controls the current flowing through the LEDs to vary with changes of supply voltage, so as to enable effectively increased power factor and reduced harmonics, as well as effectively lowered manufacturing and material costs.

Abstract: A protection circuit of a backlight driver circuit includes a backlight driver circuit. The backlight driver circuit includes a backlight driver integrated circuit (IC), and the backlight driver IC includes a protection pin that controls the backlight driver IC to enter a protection mode. The backlight driver circuit further includes a protection circuit, and the protection circuit includes a monitoring unit that monitors a temperature of the backlight driver circuit. When the temperature of the backlight driver circuit exceeds a preset temperature, the monitoring unit sends the protection signal to the protection pin to control the backlight driver IC to enter the protection mode.

Abstract: There is provided a lamp capable of informing a user that the LED lamp is at the end of its productive life and urging the user to replace the lamp reliably with a simple configuration. The lamp includes: a light emitting diode (1) as a light source; and a driving circuit (3) that turns on the light emitting diode (1) by an alternating-current or direct-current power source. The lamp further includes a life detecting element (2) that turns off the light emitting diode (1) following the occurrence of insulation deterioration in a resin material when the light emitting diode (1) has been operated for a predetermined time.

Abstract: A power supply or driver circuit configured to provide electrical energy at a drive voltage. The driver circuit converts electrical energy at an input voltage to the electrical energy at the drive voltage. A controller is configured to control the power converter to provide electrical energy at the drive voltage. The controller stops operation at an interruption of electrical energy to the driver circuit. The controller is configured to resume operation subsequent restoration of electrical energy to the driver circuit. The controller is configured to maintain the timing voltage above a first voltage level when the controller is in operation and to determine the duration of an interruption of electrical energy to the driver circuit.

Abstract: A light emitter diode (LED) driver drives a string of light emitting diodes. A rectifier receives an alternating current (AC) signal across two inputs and produces a direct current (DC) signal across two outputs. The two outputs are connected to ends of the string of light emitting diodes. A first capacitor is connected between a first input of the rectifier and an alternating current source. Current through the string of light emitting diodes is controlled by capacitive reactance of the first capacitor. A second capacitor is connected between the two outputs of the rectifier. A capacitive value of the second capacitor is selected to limit acoustic humming of the LED driver.

Abstract: An electrical circuit is described that comprises a first string and second LED string coupled in parallel, a first and second transistor, at least one bypass transistor, and a controller. The first transistor is coupled to the first LED string at a first terminal of the first transistor. The second LED string includes multiple LED color strings coupled in series. The second transistor is coupled to the second LED string at a first terminal of the second transistor. The bypass transistor is coupled to one of the color strings. A first terminal of the bypass transistor is coupled to a first terminal of the color string. The second terminal of the bypass transistor is coupled to a second terminal of the color string. The controller controls a gate voltage of the first and second transistors and the bypass transistor to operate all transistors in linear modes.

Abstract: Electrical and mechanical connection for a series connected LED lamp to an appropriate electrical circuit. The circuit contains additional series connected light producing elements. To enable continuous operation of all the other light producing elements in the series circuit, the socket contains a device to bypass the series current to the remaining circuit elements in the case of a defective lamp or connection. Operation of the bypass device is controlled within the socket with operational parameters controlled either from within the socket or in conjunction with an external element in the lamp. The operation of the bypass circuit is latching, once operating the bypass will continue to operate until reset preventing unwanted flicker in the case of intermittent connections. The method of resetting the bypass circuit may be either manual or automatic. The socket bypass may contain a time delay to allow internal bypass circuits included within the lamp to operate before the socket bypass activates.

Abstract: A bleed circuit is applied to a transformer based on a bleed-on time and a bleed-off time determined by monitoring an output voltage waveform of the transformer.

Abstract: A LED driving device adapted to driving N LED strings connected in series is provided. N is a positive integer greater than 1. The LED driving device includes (N?1) switch units, a current source, a detection unit and a control unit. The ith switch unit electrically connects to the (i+1) LED string in parallel or to the ith LED string in parallel, and 0<i?(N?1). The current source supplies a driving current to drive the N LED strings. The detection unit outputs a detection signal according to a voltage of the current source, a first reference voltage and a second reference voltage. The control unit outputs a plurality of first control signals according to the detection signal to dynamically control an amount of the (N?1) switch units turned on.

Abstract: A light emitting diode (LED) backlight driving circuit includes an LED light bar, a power supply that drives the LED light bar to light, a short-circuit protection unit, and a divider resistor. An output end of the LED light bar is coupled to the short-circuit protection unit and the divider resistor. The short-circuit protection unit includes a comparing unit and a driving unit coupled to the comparing unit. Voltage of two ends of the divider resistor is regarded as a feedback voltage, and the feedback voltage and a first reference voltage are input to the comparing unit. When a difference value of the first reference voltage subtracted from the feedback voltage is greater than a preset deviation value; the driving unit controls the power supply to turn off. When brightness of one normal LED light bars reaches a maximum, the first reference voltage is greater than or equal to voltage of two ends of the divider resistor corresponding to the one normal LED light bar.

Abstract: The invention relates to an LED lamp (1, 1?, 1?, 1??, 1??) comprising at least one light emitting diode (LED, 2) arranged in a housing (3), and an isolation monitoring device (4) configured to determine a defect of the housing (3) and disconnect said at least one LED (2) from power in case said defect is detected, to enhance the safety of the LED lamp (1, 1?, 1?, 1??, 1??) and reduce the risk of electric shock for a user.

Abstract: The present disclosure relates to a method and apparatus for controlling an illumination device, such as a light bulb, LED light, or the like. In one embodiment, a lighting control adapter is described, comprising a male base for physically attaching the lighting control adapter to a light fixture and for receiving power from the light fixture via a light switch connected to the light fixture, a female socket for receiving a base of an illumination device, a switching circuit for providing switchable power to the illumination device, and a processing circuit coupled to the switching circuit, for detecting one or more power toggles of the power received by the male base, and for controlling illumination of the illumination device based on the detection of one or more detected toggles.

Abstract: A backlight driving circuit includes a power module and a constant current driver chip. The power module includes a first controllable switch. An adjustable load is connected between the first controllable switch and a round terminal of the backlight driving circuit, and the adjustable load includes a switching module controlling a resistance value of the adjustable load, a switching mode signal of the backlight driving circuit is sent to a control end of the switching module.

Abstract: Systems and methods for preventing or otherwise reducing cyclic light output caused by failure modes are disclosed, which shut off a power supply to a lighting system susceptible to output cycling (also known as flashing, flickering, or strobing) in a non-latching fashion. A power supply and/or driver system includes a processor and memory arrangement configured to track failures and prevent cyclical behavior when detected. The processor can be implemented, for example, with an existing microcontroller already present in the power supply, or as a dedicated processor. Once a failure mode that exhibits cyclic behavior above a certain frequency is detected, the power supply can be turned off or otherwise prevented from attempting to source power to the lighting system.

Abstract: Systems and methods for detecting an incorrect load and preventing powering of that load, until a load change is detected, are disclosed. An incorrect load can be removed and a newly attached valid load can be operated without requiring a reset. A power supply or driver system for a lighting system including one or more solid state light sources includes the systems and methods. The power supply or driver system includes a processor and memory arrangement configured to detect whether a load is operable or non-operable while still being responsive to a new load being attached at any time, and to prevent the system from checking the same load more than once. These may be used in conjunction with features like auto-recovery, restart after faults, and load-hot-plug capability, while perhaps simultaneously reducing cyclical flashing of light output.

Abstract: Lighting systems including lighting fixtures having multiple light-emitting diode units and associated devices, systems, and methods are disclosed herein. A lighting system configured in accordance with a particular embodiment includes a plurality of lighting fixtures individually including first and second light-emitting diode units. The system further includes a power source, first wiring operably connecting the first light-emitting diode units to the power source, and second wiring operably connecting the second light-emitting diode units to the power source. An automatic controller is operably connected to the first wiring such that the second light-emitting diode units operate independently of the automatic controller.

Abstract: A solid state lighting apparatus can include an electrical connector that is configured to releasably couple to a standardized electrical fixture having ac voltage provided thereat, where the electrical connector includes an opening that is configured to provide a recess in the electrical connector including an interior contact to provide the ac voltage in the recess when connected to the standardized electrical fixture. A protective circuit stage of a solid state lighting driver circuit can be in the recess to electrically coupled to the interior contact. An electrical wire can include a first portion that can be electrically coupled to the protective circuit stage in the recess and a second portion that is outside the recess. A solid state lighting housing can be configured to releasably couple to the second portion of the electrical wire.

Abstract: A power supply circuit (4) is responsive to an activating signal by supplying a discharge lamp (2) with an operating voltage on which a high voltage is temporality superposed. An insufficient current detecting circuit (46) detects abnormality of an output current supplied to the discharge lamp (2) from the power supply circuit (4). A CPU (52) stops the operation of the power supply circuit (4) in response to detection of abnormality by the insufficient current detecting circuit (46). An output nullification time period timer (50) nullifies the output of the insufficient current detecting circuit (46) for a predetermined time period measured from the supplying of the activating signal.

Abstract: In examples of the embodiment, a surge-proof interface circuit (100) comprises a rectifier circuit (20) which is configured to produce a rectified rectifier output voltage at the rectifier output terminals (20c, 20d), in accordance with a rectifier input voltage at the rectifier input terminals (20a, 20b), and a Darlington circuit (30) which comprises at least two transistors (Q3, Q4). Said Darlington circuit (30) comprises a current path (35) which can be controlled on the output side in accordance with a control signal (62) and said current path (35) which can be controlled on the output side is coupled between the rectifier output connections (20c, 20d).

Abstract: An LED drive circuit is an LED dive circuit that receives an alternating voltage to drive an LED, and includes a current remove portion that removes a current from a current supply line that supplies an LED drive current to the LED. If an input current to the LED drive circuit is an unnecessary current, the LED does not light because of current removal by the current remove portion. If the input current to the LED drive circuit turns into the LED drive current from the unnecessary current, the current remove portion decreases the amount of current removed.

Abstract: A driving circuit with an over-voltage protection device for modulating an electrical parameter of a driven device includes at least a boost circuit, a signal processing circuit, an over-voltage protection device, a modulation device and a control circuit. The output terminal of the boost circuit is electrically coupled in series to a driven device, a transistor and a grounded feedback resistor sequentially, wherein the output terminal of the boost circuit is further electrically coupled to a voltage dividing circuit for outputting a voltage dividing signal. The signal processing circuit is provided for outputting a processing signal to the over-voltage protection device and the modulation device according to the voltage dividing signal and a modulation signal. The control circuit is provided for turning on the transistor or not according to an output signal of the over-voltage protection device and an output signal of the modulation device.

Abstract: Electrical equipment includes a switching power source, a rectifier circuit, a pair of capacitative elements, and a load. The switching power source outputs an alternating-current voltage with input of a direct-current or an alternating-current power source voltage. The pair of capacitative elements are connected between the switching power source and the rectifier circuit and insulate the switching power source and the rectifier circuit. The load is connected as a load circuit to an output of the rectifier circuit and driven by a constant current.