Abstract: The present invention provides an LED backlight driving circuit and an LED backlight driving method. The circuit includes an isolation MOS transistor, a dimming MOS transistor connected in parallel to the isolation MOS transistor, and first and second resistors. The first resistor and the second resistor are connected to each other in parallel and are connected between the dimming MOS transistor and a ground wire. The isolation MOS transistor and the dimming MOS transistor are arranged for electrical connection with an LED light. The LED backlight driving circuit arranges the isolation MOS transistor and the dimming MOS transistor to connect in parallel to each other so as to make the electrical current flowing through the isolation MOS transistor lessened to reduce the amount of heat emitting therefrom and enhance operation safety and also allow the MOS transistor used to be of a downgraded specification to lower down the manufacture cost.

Abstract: An LED drive circuit comprises a power supply unit, a first LED lamp string, a first voltage control unit, a second LED lamp string and a first power transfer unit. The power supply unit outputs a drive power to drive the first LED lamp string. The first voltage control unit gets the drive power and stabilizes and provides the voltage to the first LED lamp string. The first voltage control unit includes a power switch where the drive power generates a power loss. The second LED lamp string and first power transfer unit are coupled in series with the first voltage control unit so that the power loss is transferred and output to drive the second LED lamp string. Thus loss of the drive power is reduced and lighting efficiency of the LED improves.

Abstract: Disclosed are methods and lighting system with LEDs. An exemplified system comprises series-coupled light-emitting diodes, an integrated circuit, and an energy storage apparatus. The series-coupled light-emitting diodes are divided into several LED groups coupled in series. The integrated circuit comprises nodes respectively coupled to the LED groups, for providing a driving current to selectively flow through at least one of the LED groups. The energy storage apparatus has two ends coupled to a predetermined LED in a predetermined LED group. When the driving current flows through the predetermined LED group the energy storage apparatus energizes; and when the driving current does not flow through the predetermined LED group the energy storage apparatus de-energizes to illuminate the predetermined LED.

Abstract: There is provided an alternating current (AC) driven light emitting device including a plurality of LED arrays connected in series, each having a structure in which a plurality of LEDs are electrically connected to form a two-terminal circuit and emit light by a bidirectional voltage when an AC voltage is applied to the two-terminal circuit; and a switching device connected to at least one of the plurality of LED arrays and controlling a total driving voltage with respect to the plurality of LED arrays. The AC driven light emitting device permits operation from a low driving voltage Vf while having a high driving voltage at a high voltage Vf, thereby achieving excellence in terms of power factor, THD, and energy efficiency.

Abstract: A solid state lighting switch can include a first input control that can be configured to adjust a dimming indication or color indication for a solid state lighting fixture that is configured for coupling to the solid state lighting switch. A selective linking mechanism can be configured to activate a linked mode of operation of the switch to link the dimming indication to the color indication or to activate an unlinked mode of operation of the switch to unlink the dimming indication from the color indication.

Abstract: The present invention provides a circuit for driving a vehicle lamp, comprising a dummy load. Multiple unidirectional conduction electronic components are coupled to the dummy, operable for conducting a current path to enable a current to flow through the dummy load. Each of multiple LED strings is coupled to each of the multiple unidirectional conduction electronic components, respectively.

Abstract: A capacitive full-wave circuit for LED light strings makes use of capacitors and diodes together to drive a LED string with full AC waves. Different from the conventional four-diode full-wave rectifying circuit, one embodiment of capacitive full-wave circuit includes two capacitors and two diodes. Because of the large imaginary impedance, the capacitors not only limit and the voltage and current through the LEDs, but also consume almost no electrical power. The electrical current-voltage performance can be further improved by introducing four resistors with a cost of some additional power consumption. A LED light string module with the capacitive full-wave circuit is also presented, with the capacitive full-wave circuit integrated inside of a front power plug and a back power socket.

Abstract: A power-factor-corrected power supply adapted to supply power to one or more light emitting diodes (LEDs), comprises: a triac dimmer electrically connected between an alternating current source and a bridge rectifier; a damping circuit electrically connected between the alternating current source and the bridge rectifier; a bleeder circuit configured to conduct current between a supply terminal of the bridge rectifier and ground only when a triac in the triac dimmer is not conducting current; a fast startup circuit configured to conduct current between the supply terminal of the bridge rectifier and a voltage supply terminal of a power-factor-corrected controller when the triac dimmer is initially turned on until a supply voltage capacitor coupled to the voltage supply terminal of the power-factor-corrected controller has charged; a dimming slope control circuit configured to reduce a first voltage sensed at a current sensing terminal of the power-factor-corrected controller, such that a reduced amount of cur

Abstract: A driving circuit includes a plurality of light-emitting units, a plurality of switches, and a voltage generating module. The light-emitting units are coupled with each other in series and are driven with an input voltage varying according to a frequency. Each switch has a preset voltage and an activation voltage and includes a light-emitting end, a control end, and a setting end. The light-emitting ends are coupled with the light-emitting units, and the setting ends of the switches are coupled with each other. The voltage generating module includes a plurality of control units and provides a plurality of control voltages to the switches, and each switch is driven to be activated or to be deactivated according to a relation of the preset voltage and a difference between the control voltage and the activation voltage when the input voltage drives the light-emitting units, the switches, and the control units.

Abstract: A light emitting unit includes a plurality of light emitting devices. A control apparatus includes a rectifier for converting an alternating current (AC) signal into a ripple signal by rectifying the AC signal. A ripple signal adjuster reduces a level difference between maximum and minimum levels of the ripple signal, and outputs the resultant ripple signal as a drive signal. A turning-on controller controls turning-on of the light emitting devices in accordance with a level variation of the drive signal.

Abstract: A phototherapy or photobiomodulation process employing the application of electromagnetic radiation (EMR) to a living organism, typically a human being. The EMR is generated by one or more strings of LEDs and is programmed to emit one or more wavelengths, typically in the visible and infrared portions of the spectrum, the EMR in each wavelength being delivered in pulses having specified on-times, off-times, photoexcitation frequencies, duty factors, phase delays, and power amplitudes. A system for providing such EMR includes a microcontroller having a pattern library of algorithms, each of which defines a particular sequence of synthesized pulses, and an application pad, preferably flexible, containing the LED strings.

Abstract: An indication circuit is used on a motherboard. First and second pins on the motherboard output different signals corresponding to different power-on self-test errors. The indication circuit includes first to third electronic switches, first and second light-emitting diodes, and first to fifth resistors. When different errors occurred during power-on self-test, different signals are output from the first and second pins on the motherboard, such that to make the first and second light-emitting diodes activated or deactivated. As a result, the indication circuit can indicate different errors when the motherboard is performing power-on self-test.

Abstract: A backlight unit and a display device including the same are disclosed. The backlight unit includes a substrate and a plurality of light sources disposed on the substrate. The plurality of light sources are divided into a plurality of groups each including at least one light source. The plurality of groups are electrically connected in series with one another. A switching element is electrically connected in parallel with each of the plurality of groups.

Abstract: An apparatus includes an input node, a light-emitting diode (LED) string to receive a current from the input node, a voltage divider to output a control voltage, and a switch to receive the control voltage. The switch coupled to the LED string controls the current through the LED string according to the control voltage.

Abstract: A lighting unit includes at least two channels of light sources, and a driver for the light sources. The driver includes a DC/DC converter and a control arrangement for controlling the current supplied to at least one of the two channels in response to a control signal produced by the DC/DC converter. Beneficially, a feedback loop controls a switching device in the DC/DC converter to maintain the light level produced by the light sources at a desired level regardless of changes in the supply voltage arid the load.

Abstract: A string of LED loads is supplied by means of a rectified mains voltage. A cathode of each LED load is coupled to ground by means of a string. The strings are made conductive and non-conductive one by one in dependency of the instantaneous value of the rectified mains using both voltage and current sensing.

Abstract: A driving arrangement for light emitting diode (LED) based illumination constituted of: a comparison circuitry arranged to compare an integral of a target current over a target illumination time for at least one LED based luminaire with an integral of an illumination current over an illumination time for the at least one LED based luminaire, the comparison circuitry arranged to output a comparison signal; and a control circuitry in communication with the comparison circuitry and arranged to alternately: allow the flow of electrical current through the at least one LED based luminaire responsive to a first condition of the comparison signal; and prevent the flow of electrical current through the at least one LED based luminaire responsive to a second condition of the comparison signal, the second condition different from the first condition.

Abstract: The invention describes an adaptive circuit (1, 1?) for driving a lower-voltage DC load (2) from a rectified higher-voltage AC supply (3), which adaptive circuit (1, 1?) comprises a charge-storage circuit (21, 21?), which charge storage circuit (21, 21?) comprises a first capacitor (C1) and a second capacitor (C2) connected essentially in series, wherein the second capacitor (C2) is connected at least in parallel with the load (2); and an active switch (22, 22?) realized as a controlled current source (22, 22?) for controlling a load current (Iload) through the load (2) such that, in a closed switch state, load current (Iload) is drawn essentially from the first capacitor (C1) of the charge-storage circuit (21, 21?), and, during an open switch state, load current (Iload) is drawn essentially from the second capacitor (C2).

Abstract: An inductorless LED driver powers a string of low current LEDs. A phase controlled triac dimmer, serially connected to a full-wave rectifier circuit, performs as an LED current and triac holding current control element. The output of the full-wave rectifier circuit is divided into two circuit paths; the first path provides power to drive a string of serially-connected low-current LEDs, and the second path connects to a dynamic load, which supplies a holding current that flows through the triac dimmer. There are two feedback control systems; the first regulates the luminance of the LEDs; the second regulates the triac holding current to eliminate lamp flicker.

Abstract: A LED lighting system includes: a power unit for providing a power supply source for the lighting system, a LED circuit connected to the power unit for illuminating the light emitting diodes of the LED circuit, a heat control unit connected between the power unit and the LED circuit for controlling heat as produced, and a heat dissipating device thermally connected to the heat control unit for outwardly dissipating the heat produced by the lighting system for preventing light attenuation or damage of the light emitting diodes.

Abstract: The present invention relates to an apparatus for controlling the operation of an LED and to a method for controlling the drive current thereof. More particularly, the present invention relates to an apparatus for controlling the operation of an LED, which is capable of driving a direct current-operated LED module or an alternating current-operated LED module using alternating current power, and to a method for controlling the drive current of the apparatus. According to the present invention, the drive current of an LED array can be output in the form of a sine wave by a constant-current regulation or constant-power regulation even when input voltage varies, thus suppressing harmonics, improving the power factor, minimizing flicker, and preventing a temperature increase in the LED array and in an LED operation control circuit.

Abstract: The present invention discloses a LED backlight driving method, a LCD device and a LED backlight driving circuit, wherein the LED backlight driving method comprises the following steps: regulating the current of each LED string so that the voltages of all LED strings are equal; and regulating the duty cycle of the current of the corresponding LED string so that the effective value of the current of each LED string meets the preset requirement of brightness. The present invention solves the problem of consumption caused by voltage difference by regulating the current through the current regulation module to ensure that the voltages of all the LED strings are equal, and ensures the brightness consistency by regulating the duty cycle through the duty-cycle regulation module so that the effective value of the currents of all the LED strings are equal.

Abstract: An improved LED provides power efficient lighting while accepting a wide range of input voltages. The improved LED may comprise a controller that may measure a voltage, current, or other characteristics of input power and modify operation of the improved LED accordingly, such as to accept significantly more voltage or significantly less voltage while providing consistent light output. This allows light bulbs or other lighting to be easily manufactured with the improved LED. The improved LED may comprise the controller and one or more LED dies enclosed by a substrate and lens structure. Depending on the configuration of the controller, the improved LED may also provide time, temperature, and other measurement/response functions to help ensure consistent light output.

Abstract: A rotary switch is provided for controlling an attached light string containing a plurality of light colors. By manipulation of the control dial, a specially designed rotary board is rotated to provide electrical connection to the light string according to one of several present color patterns preprogrammed into the rotary board. The discrete rotary switch positions provided by the rotary switch allow for different color signaling patters to be provided at the output leads from the rotary switch so as to power a multicolored light staring with different patterns and create different multicolored effects. One of the discrete rotary switch positions permits the input color patter from an input light string to be passed through the rotary switch so as to provide the same color pattern at the output leads and power a multicolored light string with the same color pattern provided by the input light string.

Abstract: A lighting apparatus includes a rectifier circuit configured to be coupled to an AC source and to produce a rectified voltage from an AC voltage and a string including at least two serially-connected LED segments and coupled to the rectifier circuit. A segment control circuit is configured to selectively bypass at least one segment of the string responsive to the rectified voltage. An energy storage circuit is coupled to the rectifier circuit and controls current flow between at least one energy storage device and the string. A control circuit controls the segment control circuit and the energy storage circuit. The segment control circuit may support a current from the rectifier circuit through all of the segments in the string circuit at a peak of the rectified voltage and the energy storage circuit may charge the at least one energy storage device to a voltage near the peak of the rectified voltage.

Abstract: A LED driving apparatus and an operating method thereof are disclosed. The LED driving apparatus includes a controller and an output stage. The output stage includes at least one LED, a switch, and a setup resistor. The at least one LED, the switch, and the setting resistor are coupled in series between an input voltage and ground. The controller is coupled to the input voltage and the switch respectively. The controller receives at least one voltage sensing signal and outputs a setup voltage signal to the output stage. The at least one voltage sensing signal is received from the node between the at least one LED and the switch, between two LEDs, or between two voltage dividing resistors coupled in series between the input voltage and ground.

Abstract: A solid state lighting driver and system having a total harmonic distortion (“THDi”) bypass circuit is disclosed. The solid state driver energizes a solid state lamp having a first lighting segment serially connected to a second lighting segment. The THDi bypass circuit bypasses a first lighting segment and energizes a second lighting segment of LEDs when the driving voltage is low. As a result, the solid state lamp will emit light over a larger portion of the power cycle and will decrease the THDi.

Abstract: A voltage level supplied to power a plurality of LED light fixtures is dynamically adjusted to control the headroom of the voltage level. The current drawn by at least one of the plurality of LED light fixtures is monitored, and the voltage is increased from zero until the monitored current reaches its maximum.

Abstract: The present invention provides an LED module and an LED light string using the same. The LED module has an input terminal, an output terminal, a primary LED, a spare LED and a switching module. The switching module controls the spare LED to be switched off while the primary LED is switched on; and controls the spare LED to be switched on while the primary LED is burned out. Hence, the present invention extends a service life of the LED light string using the LED modules in the backlight module.

Abstract: A cascoded current regulator, including: a first load circuit, having a first load and a current source unit; and a second load circuit, being cascaded with the first load circuit and having a second load and a current mirror unit, wherein a first current flowing through the first load and a second current flowing through the current source unit are controlled by a control voltage, and a third current flowing through the second load and a fourth current flowing through the current mirror unit are generated according to the second current.

Abstract: An LED-based lighting apparatus includes a plurality of LED-based lighting segments connected in series with a current control device. Each lighting segment has at least one LED-based lighting unit connected in series. A plurality of switch controllers controlled by a switching voltage comparator unit is connected with the plurality of LED-based lighting segments to provide multiple operation modes for turning on different number of LED-based lighting segments. In one embodiment, each switch controller is connected in parallel with a corresponding segment. The switching voltage comparator unit generates a propagation signal that propagates through and controls the plurality of switch controllers. In the other embodiment, each switch controller is connected between a positive end of the corresponding segment and a current control device. The switching voltage comparator unit generates two propagation signals that propagate through and control the plurality of switch controllers.

Abstract: An electronic circuit for driving a plurality of light emitting diode (LED) channels coupled to a common voltage node includes a priority queue for tracking a dominant LED channel. A queue manager may be provided to keep the priority queue updated during LED drive operations based on operating conditions associated with the LED channels.

Abstract: An electronic circuit includes a driver for an LED light, having an isolated DC-DC converter having a first output at a higher voltage referred to a floating ground and a second output at a lower voltage than said first output and referred to a reference voltage. A DC-DC boost converter receives its input power from the second output of the isolated DC-DC converter and having its output coupled to the floating ground, whereby an output voltage to a LED light receives the sum of the voltages of the first output of the isolated DC-DC converter and the output of the DC-DC boost converter.

Abstract: A plurality of switching units interleaves with a plurality of LED-based lighting units to configure the interconnection of the LED-based lighting units for providing multiple lighting modes. Each switching unit disposed between a leading lighting unit and a trailing lighting unit is separately controlled by a controller. The switching unit can be configured to connect the two LED-based lighting units in parallel or in series, or to bypass the leading LED-based lighting unit. All the LED-based lighting units are connected in series when an input voltage supply is at a maximum voltage level, and connected in parallel when the input voltage supply is at a minimum voltage level. As the input voltage level decreases, the number of LED-based lighting units connected in parallel increases, and vice versa.

Abstract: The present invention provides a high-voltage alternating current light-emitting diode (AC LED) structure. The high-voltage AC LED structure includes a circuit substrate and a plurality of AC LED chips. The AC LED chips each include an insulated substrate, an LED set, a first metal layer and a second metal layer. The AC LED chips manufactured by a wafer level process are coupled to the low-cost circuit substrate to produce the downsized high-voltage AC LED structure.

Abstract: A circuit for driving multiple light emitting diodes (LEDs) includes at least two sets of LEDs, each set comprised of one or more LEDs in series. The circuit further includes a single inductor connected in series with the two sets of LEDs. At least one set of LEDs is connected to a shunting transistor connected in parallel with the set of LEDs. The duty cycle of the shunting transistor is controlled by a single controller connected to the shunting transistor and the inductor.

Abstract: An LED controller and a method for controlling an LED device is disclosed. A current sense signal is representative of a load current flowing through the LED device. The current sense signal is compared with an upper threshold value and a lower threshold value. Current is provided to the LED device via an inductor coupled in series with the LED device when the current sense signal exceeds the upper threshold. A load current loop is closed over a free-wheeling diode when no current is provided to the LED device while the current sense signal is below the lower threshold. The upper threshold and the lower threshold are adjusted dependent on the current sense signal such that peak values of the current sense signal match corresponding desired peak values.

Abstract: An apparatus for controlling an LED string is provided, in Which each high voltage (HV) N-type device has one end electrically connected or coupled with the corresponding LED unit and the other end coupled with a corresponding low voltage (LV) current limit switch via a corresponding path. The LV current limit switch is switched according to the voltage or current detected on the path. Since the current flowing through the HV N-type device increases or decreases with that flowing through the corresponding LV current limit switch, the HV N-type device will be indirectly controlled.

Abstract: A series arrangement of LED loads (LP1-LP4) is coupled between output terminals of a rectifier having its input terminals coupled to a mains supply supplying a low frequency AC voltage. Control means render the LED loads conductive one by one, when the amplitude of the supply voltage increases, and non-conductive one by one when the amplitude of the supply voltage decreases. The first LED load (LP1, LP2) has a forward voltage that is substantially higher than that of the other LED loads. As a consequence, the LED utilization is comparatively high, thus allowing the LED loads used in the series arrangement to be comparatively cheap.

Abstract: LED light source comprising a string of LED loads (LED1-LED4) supplied by a rectified mains voltage. The number of LED loads carrying current is increased as the momentary amplitude of the rectified mains voltage increases, and is decreased as the momentary amplitude of the rectified mains voltage decreases. The order in which the LED loads start carrying a current and the order in which the LED loads stop carrying a current is reversed for each half period of the mains.

Abstract: System and method are provided for regulating a string current flowing through a string of one or more light emitting diodes. A system controller includes a first controller terminal, a second controller terminal and a third controller terminal. The first controller terminal is coupled to a base terminal of a bipolar junction transistor, the bipolar junction transistor further including an emitter terminal and a collector terminal, the collector terminal being connected to the string of one or more light emitting diodes. The second controller terminal is coupled to the emitter terminal of the bipolar junction transistor and to a first resistor terminal of a resistor associated with a resistance. The third controller terminal is coupled to a second resistor terminal of the resistor. In addition, the system controller is configured to receive a reference voltage, receive an emitter voltage, and output a base current.

Abstract: A lighting unit includes at least two channels of light sources, and a driver for the light sources. The driver includes a DC/DC converter and a control arrangement for controlling the current supplied to at least one of the two channels in response to a control signal produced by the DC/DC converter. Beneficially, a feedback loop controls a switching device in the DC/DC converter to maintain the light level produced by the light sources at a desired level regardless of changes in the supply voltage and the load.

Abstract: Circuits and methods to achieve a most efficient driver for white LEDs are disclosed. Switching Losses associated with the switching activity of a boost converter and mainly depending on clock frequency and total capacitance at the switching nodes and conduction losses associated with the current flowing in the boost converter and mainly depending on the series resistance of the elements in the regulation loop are minimized by using a size programmable NFET power switch with constant current limit, a very low voltage and accurate programmable current source, a programmable reference voltage for the error amplifier, and a PWM generator with programmable clock frequency. A limited number of configuration windows corresponding to a set of programmable values (OTP registers) for specific ranges of the current fed to the WLEDs.

Abstract: A control circuit (1) for light emitting diode arrangements (11), used particularly for backlighting LC flat screens. The circuit has a plurality of control channels (5, 5?) in each of which one or more light emitting diode arrangements (11) are disposed. The circuit has a balancing device (23) which allows currents in the individual control channels (5, 5?) to be balanced. Each control channel (5, 5?) has a separate dimming device (13) through which a brightness of the light emitting diode arrangements (11) in this control channel (5, 5?) can be changed separately from the other control channels (5, 5?). For this purpose, the control circuit has a compensation device (16) which allows a flow of current in the individual control channels (5, 5?) to be balanced when the light emitting diodes have different brightnesses.

Abstract: A light emitting diode (LED) backlight driving circuit includes LED lightbar(s) and a control module; the control module includes a dimming controllable switch. The LED lightbars are connected with the dimming controllable switch in series. Two ends of the dimming controllable switch are connected with a varistor in parallel. Because two ends of the dimming controllable switch are connected with a varistor in parallel, when the dimming controllable switch is switched off, a current of the branch circuit is suddenly reduced, the voltage withstood by the LED lightbars is greatly reduced, and the voltage on two ends of the dimming controllable switch is increased. Then, under action of high voltage, resistance of the varistors connected in parallel is reduced, and the current of a new branch circuit formed by the LED lightbars and the varistor is also increased. Thus, the voltage withstood by the LED lightbars is increased again and the voltage on two ends of the dimming controllable switch is reduced.

Abstract: In a method of lighting at least part of a space, a light emitting diode (LED) string is used. The LED string comprises a first LED segment and at least one further LED segment, which are connected in series, each LED segment comprising at least one LED. The LED string is powered by a rectified AC voltage. The first LED segment is powered when the rectified AC voltage is above a first voltage level, and the first LED segment and the further LED segment are powered when the rectified AC voltage is above a second voltage level higher than the first voltage level. The first LED segment is arranged to radiate light to a first volume of the space, and the further LED segment is arranged to radiate light to a second volume of the space, the first volume being at least partly different from the second volume. The first volume may at least partly overlap the second volume.

Abstract: There is provided a light emitting diode apparatus for operation with varying input electrical sources. The apparatus comprises an array of light emitting diodes to produce light, and a variable input power supply adapted to provide an electrical supply of predetermined value to the light emitting diodes from a varying electric signal provided by varying input electrical sources. In one embodiment, the light emitting diode apparatus is for use as a replacement of a fluorescent tube in an existing fluorescent fixture. In another embodiment, the light emitting diode apparatus is for use with connection to conventional AC voltage sources used throughout the world.

Abstract: Disclosed are a controller and a relevant LED lighting module. A disclosed controller comprises a high-voltage power terminal and a low-voltage power terminal, a major switch circuit, an upward-connection terminal and a downward-connection terminal, and a management circuit. The major switch circuit is coupled between the high-voltage and low-voltage power terminals, and has a driving terminal for coupling to at least one LED. The management circuit is coupled to control the major switch circuit, and configured to communicate with an upstream controller via the upward-connection terminal and to communicate with a downstream controller via the downward-connection terminal. The upward-connection terminal is coupled to the downward-connection terminal of an upstream controller. The downward-connection terminal is coupled to the upward-connection terminal of a downstream controller. The management circuit is capable of operating in one of operation conditions.

Abstract: A LED string driving circuit includes a plurality of LED strings; a power supply unit configured to receive an input voltage and accordingly output a driving voltage to the LED strings; a comparison unit configured to receive the input voltage and output a first control signal according to a relationship between the input voltage and a predetermined voltage; a control unit configured to receive the first control signal and generate a second control signal according to a potential level of the first control signal; and a switch unit including a plurality of switch elements, and each are controlled by the second control signal and thereby forming various electrical loops and thereby configuring the LED strings corporately to form either a parallel loop or a series loop via the switch unit with respective electrical loops. A LED string driving method is also provided.

Abstract: A control circuit for an electrical load in an electronic device includes a voltage divider, a current measurement circuit, a variable-current-output switch and a comparison circuit, the voltage entering the load and the voltage (and thus current) exiting from the load being monitored and compared to a reference voltage, any difference causing the switch to dynamically adjust the level of current being supplied, to protect the load from sudden variations in power supply and ensure a stable and constant supply of power.