Abstract: A protection circuit for protecting a rechargeable battery is provided. The protection circuit includes a voltage-threshold generating unit and a comparing unit. The voltage-threshold generating unit is for generating a threshold voltage. The comparing unit is for comparing the threshold voltage to the rechargeable battery voltage and outputting a charging enable signal or a charging disable signal according to the comparison result. The comparing unit outputs the charging enable signal if the amplitude of the threshold voltage is lower than that of the rechargeable battery, or outputs the charging disable signal as the amplitude of the threshold voltage is equal to or higher than that of the rechargeable battery. A battery charger apparatus using the protection circuit is also provided.

Abstract: Disclosed are methods and corresponding systems to detect and prevent and/or eliminate overload conditions for a transistor. According to an embodiment, a method includes providing an input signal to a base terminal of a transistor for a first amount of time, determining if an overload condition exists at the transistor, disabling the transistor for a second amount of time when the overload condition exists at the transistor, and providing the communication signal to the base terminal upon expiration of the second amount of time. Additional overload conditions can be checked upon expiration of the second amount of time as well.

Abstract: A surge suppression circuit for a load control device allows the load control device to pass hipot testing, while providing improved protection of the load control device during surge events. The load control device comprises a load control circuit and a filter circuit for preventing noise generated by the load control circuit from being provided to an AC power source. The surge suppression circuit comprises a clamping device adapted to be electrically coupled across the AC power source, and first and second spark gaps coupled across the filter circuit for limiting the magnitude of the voltage generated by inductive components of the filter circuit. The filter circuit may comprise a common-mode choke, and two series-connected capacitor having their junction connected to earth ground. Alternatively, the filter circuit may additionally comprise a differential-mode choke.

Abstract: An over-voltage protection circuit is disclosed herein for protection against over-voltage of an energy storage device while charging. The circuit operates within the operational limits of a battery-operated device, such as a mobile or handheld device. The over-voltage protection circuit comprises an over-voltage protection device, and an over-voltage protection controller. The controller allows current to flow to the over-voltage protection device only when an energy storage device is experiencing over-voltage. In allowing current to flow to the over-voltage protection device only when the voltage across the energy storage device is above a predetermined voltage, power conservation is achieved.

Abstract: Methods and devices of the invention include an electrostatic discharge (ESD) protection circuit. This circuit includes rise time dependent activation circuitry capable of detecting a slew rate of an input signal and capable of determining whether the slew rate of the input signal is greater than a threshold value. For an ESD event said activation circuitry generates a trigger signal. Additionally, the activation circuitry is coupled with the ESD dissipation duration control circuitry which is further coupled with an ESD dissipation circuit. This arrangement enabling the duration control circuit to be activated by the trigger signal which responds by producing an activation signal that activates the ESD dissipation circuitry and that controls the length of time the dissipation circuit remains active. The ESD dissipation circuitry includes a shunt that redirects the ESD energy away from the protected internal circuit.

Abstract: Method for protection of a switching device controlled by a control unit, through which an electric drive can be disengaged during the period of an overvoltage surge caused by a load dump in the electrical system of a vehicle, in which the drive current rises to a maximum value in a first slot within the duration of the overvoltage surge and drops in the second slot connected to the first time slot, with the following process steps: recognition of a load dump by recording a limit voltage value in the electrical system by the control unit, disengagement of the electric drive in the event of a load dump at a switching time stipulated by the control unit, which lies after the first time slot.

Abstract: A MOS-type semiconductor input capacitor protection circuit and system is described. In one embodiment, the system includes a MOS device configured as an input capacitor and configured to receive an input bias voltage. A bias monitor circuit is configured to monitor the input bias voltage and apply a selective capacitor bias voltage to the input capacitor so as to limit the voltage across the input capacitor to a level below a threshold voltage.

Abstract: An electrical circuit to minimize the damage to internal electronics in the event of a lightning strike or power surge that may flow into the unit through the home run cable used to supply power to device loads, for example load cells and weigh terminals. The circuitry can not only protect, but it can also detect and distinguish from several overvoltage and undervoltage conditions that can occur.

Abstract: An electronic device includes an electronic component and a protection circuit configured to protect the component from overvoltages. A control circuit is configured to inhibit a part of the protection circuit in the presence of a test voltage across terminals of the component.

Abstract: The invention relates to a voltage detection control technology, especially relate to a hardware overvoltage disconnecting circuit wherein a DC power supply module is disconnected from a power network when the AC power network is in the state of overvoltage. The hardware overvoltage disconnecting circuit comprises a disconnecting relay and a voltage detection circuit. The disconnecting relay is connected in series between an AC power network and a power factor correction circuit of a power supply module. A first sampling terminal of the voltage detection circuit samples the voltage of the AC power network between the AC power network and the disconnecting relay, and an output of the voltage detection circuit is connected to a control terminal of the disconnecting relay. When the AC power network is in the state of overvoltage, the disconnecting relay is disconnected and the power supply module is disconnected from the AC power network.

Abstract: An electronic system can include a switch and a regulator coupled to the switch. The switch can be used to deliver electricity from a first terminal to a second terminal. The switch can also be used to prevent the second terminal from having a level that is higher than a predefined operation level limit by controlling the status of the switch according to a supply signal at the first terminal. The regulator can be used to adjust a regulated signal at the second terminal according to the supply signal.

Abstract: The present invention relates to a protection circuit for MOS-technology field-effect transistors. The circuit comprises at least one MOSFET protected by a module for blocking said MOSFET, the module being placed between the gate of the MOSFET and an electrical conductor, the module comprising switched connection means having at least two states: a first state which connects the gate of the MOSFET to the conductor, which is maintained at an electrical potential suitable for blocking the MOSFET, this first state being activated in the presence of an alarm signal; and a second state which disconnects the gate of the MOSFET, this second state being activated in the absence of the alarm signal. The invention applies notably to the protection of the power MOSFETs included in the amplification stages of electronic systems.

Abstract: An ESD protection circuit includes a first voltage clamp, connected between a first voltage supply node and a second voltage supply node of the circuit, and a second voltage clamp, connected between the second voltage supply node and a voltage return of the circuit. The first voltage supply node is adapted to receive a first voltage which is greater than a prescribed gate oxide reliability potential of the circuit. The second voltage supply node is operative to receive a second voltage which is less than the first voltage. The first voltage clamp is operative to clamp the first voltage on the first voltage supply node to a first value during an ESD event between the first and second voltage supply nodes, and the second voltage clamp is operative to clamp the second voltage on the second voltage supply node to a second value during an ESD event between the second voltage supply node and the voltage return.

Abstract: An over-voltage protection device and a method for manufacturing the over-voltage protection device are provided. The over-voltage protection device includes a substrate, a pair of electrode layers, a mask layer, and a sealing layer. The electrode layers are disposed on the substrate, and a gap is formed between the electrode layers. The mask layer is disposed over the gap and a portion of the electrode layers. The sealing layer covers the mask layer and the gap.

Abstract: A clamp unit is adapted for controlling a clamp switch of a power supply such that the power supply outputs an output voltage in an ON mode when the clamp switch is in an ON-state and that the power supply does not output the output voltage in an OFF mode when the clamp switch is in an OFF-state. The clamp unit includes: a coupling circuit for outputting a coupling voltage in response to first and second reference voltages, and a control signal outputted by a control signal generating circuit in response to an input voltage; and a detecting circuit for outputting a clamp signal to the clamp switch in response to a first signal indicating whether the power is in the ON mode or the OFF mode, and a second signal indicating whether the power supply is to output the output voltage.

Abstract: A control circuit with protection circuit for power supply according to the present invention comprises a peak-detection circuit and a protection circuit. The peak-detection circuit detects an AC input voltage and generates a peak-detection signal. The protection circuit comprises an over-voltage protection circuit. The over-voltage protection circuit generates an over-voltage protection signal in response to the peak-detection signal. The protection circuit generates a reset signal to reduce the output of the power supply in response to the over-voltage protection signal. The present invention can protect the power supply in response to the AC input voltage effectively through the peak-detection circuit.

Abstract: The application relates to a method of enabling a high voltage input and/or output in a standard IC process, the high voltage being higher than specified for I/O transistors of the IC process. The application further relates to a transceiver IC and to an article of manufacture comprising a transceiver IC. The object of the present application is to provide an integrated circuit in a standard IC process that supports larger than specified input/output swings. The problem is solved in that providing that high voltage inputs or outputs of an IC implemented in said standard IC process comprise passive impedance transformation circuitry. This has the advantage of facilitating the use of a standard IC process for higher than specified voltage I/Os. The standard IC process is preferably a CMOS or BiCMOS semiconductor process. The invention may e.g. be used for low power communication devices, e.g. portable devices having a wireless interface, e.g. listening devices, e.g. hearing instruments.

Abstract: A communication device that establishes a communication with another communication device and supplies electric power to the other communication device by way of a transmission channel, the device comprises a supply voltage generation section that generates a supply voltage, a first detection section that detects a connection of an electric device other than the other communication device to the transmission channel, and an output control section that controls .

Abstract: An interface circuit and a communication device are provided. The interface circuit includes a transformer unit, a protection unit, and an interface unit. A secondary side of the transformer unit is connected with a chip. A first terminal of the protection unit is electrically connected with a center tap of a primary side of the transformer unit, and a second terminal of the protection unit is grounded. A first access terminal of the interface unit is connected with a first port of the primary side of the transformer unit, a second access terminal of the interface unit is connected with a second port of the primary side of the transformer unit, and a third access terminal and a fourth access terminal of the interface unit are electrically connected with the first terminal of the protection unit respectively.

Abstract: The present invention comprises a method for over-current protection. The method comprising monitoring a load current value of a load current passing through a plurality of micro-electromechanical switching system devices, determining if the monitored load current value varies from a predetermined load current value, and generating a fault signal in the event that the monitored load current value varies from the predetermined load current value. The method also comprises diverting the load current from the plurality of micro-electromechanical switching system devices in response to the fault signal and determining if the variance in the load current value was due to a true fault trip or a false nuisance trip.

Abstract: An over-voltage protection circuit is disclosed herein for protection against over-voltage of an energy storage device while charging. The circuit operates within the operational limits of a battery-operated device, such as a mobile or handheld device. The over-voltage protection circuit comprises an over-voltage protection device, and an over-voltage protection controller. The controller allows current to flow to the over-voltage protection device only when an energy storage device is experiencing over-voltage. In allowing current to flow to the over-voltage protection device only when the voltage across the energy storage device is above a predetermined voltage, power conservation is achieved.

Abstract: A circuit for protecting an electronic device from excessive voltages applied to an input or output terminal includes a solid state relay coupling the electronic device to the terminal. The solid state relay may include an opto-transistor coupled between the electronic device and the terminal and a light emitting diode optically coupled to the opto-transistor. The solid state relay is coupled in series with a current limiting device, such as one or more enhancement mode field effect transistors. A voltage detector coupled to the terminal detects a voltage larger than a specific value and causes current to flow thorough the light emitting diode, thereby interrupting the coupling between the terminal and the electronic device. The voltage detector may be coupled between two spaced-apart connections to the coupling path between the terminal to the electronic device so that the voltage detector avoids diverting current from the coupling path.

Abstract: An electrical power distribution system for an aircraft comprises a power source electrically connected to an electrical load and at least one circuit interruption device for interrupting current in the power distribution system. A distinguishing device is connected to the system for distinguishing a transient electrical event in the system from a steady-state level of electrical activity in the system, wherein the transient electrical event induces a potential difference across all or part of the distinguishing device. The circuit interruption device is operable to interrupt current flowing through the power distribution system if the potential difference across the distinguishing device exceeds a threshold voltage.

Abstract: An input surge suppression device and method that uses a simple JFET structure. The JFET has its gate clamped to a predetermined value, its the drain receives the input voltage from an input power source, its source is connected to the input of a down-stream device, and a resistor connected between the drain and the gate or between the source and the gate. Thus, when the drain voltage approximates the clamped gate voltage, the source voltage nearly equals the drain voltage. When the drain voltage rises above the clamped gate voltage, the source voltage is lower than the drain voltage. The downstream device may be a DC-DC converter and the gate is biased by the enable (EN) pin of a DC-DC converter.

Abstract: A bipolar transient clamp including a RC circuit, a clamping circuit and a breakdown circuit. The RC circuit is configured to control the rate of change of clamp. Moreover, the RC circuit is coupled between a first rail and a second rail. The clamping circuit is configured to pass a current from the first rail to the second rail. In addition, the clamping circuit is coupled to be activated by the RC circuit. The breakdown circuit is coupled between the RC circuit and the clamping circuit. The breakdown circuit is configured to increase the transient trigger voltage of the clamping circuit.

Abstract: An overvoltage protection circuit includes a voltage clamping device having a predefined voltage threshold at which it starts conducting to prevent an overvoltage condition. A switch is operable to control a flow of current from a power source to the voltage clamping device. The switch is OFF to prevent a flow of current from the power source to the voltage clamping device in response to a voltage of the power source being less than the voltage threshold such that the voltage clamping device does not exhibit a leakage current. The switch is ON to permit a flow of current from the power source to the voltage clamping device in response to the voltage of the power source being equal to or greater than the voltage threshold.

Abstract: A semiconductor package includes an electrostatic discharge rail capable of being coupled to a first conductive contact and a second conductive contact, a first portion of a voltage triggerable material between the electrostatic discharge rail and the first conductive contact; and a second portion of the voltage triggerable material between the electrostatic discharge rail and the second conductive contact. The first and second conductive contacts may be coupled to the same semiconductor device or different semiconductor devices.

Abstract: A system for power amplifier over-voltage protection includes a power amplifier configured to receive a system voltage, a bias circuit configured to provide a bias signal to the power amplifier, and a power amplifier over-voltage circuit configured to interrupt the bias signal when the system voltage exceeds a predetermined value, while the system voltage remains coupled to the power amplifier.

Abstract: A switching power supply device includes: a switching element connected through a primary winding of a transformer to an output end of an input rectifying/smoothing circuit that rectifies and smoothes an alternating current input voltage and outputs a direct current input voltage; an output rectifying/smoothing circuit that rectifies and smoothes a voltage induced in a secondary winding of the transformer and outputs a direct current output voltage; and a control circuit that controls ON and OFF of the switching element.

Abstract: Circuit and method for RC power clamp triggered dual SCR ESD protection. In an integrated circuit, a protected pad is coupled to an upper SCR circuit and a lower SCR circuit; and both are coupled to the RC power clamp circuit, which is coupled between the positive voltage supply and the ground voltage supply. A structure for ESD protection is disclosed having a first well of a first conductivity type adjacent to a second well of a second conductivity type, the boundary forming a p-n junction, and a pad contact diffusion region in each well electrically coupled to a pad terminal; additional diffusions are provided proximate to and electrically isolated from the pad contact diffusion regions, the diffusion regions and first and second wells form two SCR devices. These SCR devices are triggered, during an ESD event, by current injected into the respective wells by an RC power clamp circuit.

Abstract: A power circuit includes a gate drive sever comparator circuit operable to disconnect a pre-drive transistor circuit from ground in response to an over voltage fault condition. A back-up gate drive comparator circuit operable to switch a reference directly into a multiple of shunt MosFets such that the multiple of shunt MosFets are turned on to reverse the over voltage fault condition until voltage drops and the gate drive sever comparator circuit and the back-up gate drive comparator circuit turn off to maintain a regulated voltage between comparator controlled limits.

Abstract: An anti-lightning automatic switch for a satellite television receiver comprises a housing, external terminals which are connected with external cables are respectively arranged at two ends of the housing, wherein an on-off interface is arranged at the other end of the external terminal on one side, and internal cable is connected to the other end of the external terminal on the other side; and a guide rail unit is arranged in the housing, a driving mechanism is mounted on the guide rail unit, the driving mechanism is connected with the external terminal on the other side through the internal cable, a control circuit board and a motor controlled by the control circuit board are arranged on the driving mechanism, and a contact which is used in combination with the on-off interface is mounted at one end of the driving mechanism.

Abstract: The present invention relates to clamp protection circuit and a PFC control circuit employing such clamp protection circuit. Said clamp protection circuit comprises a high voltage isolation module used for receiving power from a high voltage power supply; a voltage clamp module used for receiving an output low voltage from the high voltage isolation module and realizing a clamp protection; and a low voltage bias module used for providing bias voltage to the high voltage isolation module and the voltage clamp module. By employing the clamp protection circuit, the precision of the clamp voltage is improved, the design is simplified and the silicon area is reduced. Meanwhile, the transient response is enhanced.

Abstract: In order to protect Magnetic Energy Recovery Switch (MERS) against an overvoltage and an overcurrent a voltage detection unit is provided for detecting the capacitor voltage of the MERS and control means is provided to control so as to turn ON the switch of the discharge circuit connected in parallel with the capacitor to make the capacitor discharge the electric charge thereof when the output of the voltage detection unit exceeds a predetermined value. Moreover, a current detection unit is interposed between the AC power supply and the load for detecting the current flowing to the load, and the current limiting is carried out by making the duty ratio of the ON/OFF of the pulse of the gate control signals of the MERS switches smaller than 0.5, when the output of the current detection unit exceeds a predetermined value.

Abstract: The invention relates to a speed controller comprising: at the input, a rectifier module (12) in order to generate, on a power bus (10, 11), a direct voltage from an alternating voltage available on an electrical supply network (A), a bus capacitor (Cb) connected between a positive line and a negative line of the power bus, an inverter module (13) supplied by the power bus and controlled to deliver an alternating voltage to an electric load (2), a device (14) for protecting the controller consisting of a first electronic switch of the JFET transistor type (T1) and a second electronic switch (T2) mounted on the power bus, in parallel with the JFET transistor (T1).

Abstract: A DC/AC inverter substrate includes a voltage abnormality detector circuit. All of a high voltage side detection sensor, a low voltage side detection sensor, and a high-voltage and low-voltage detection sensor in the voltage abnormality detector circuit are disposed without being electrically connected to a secondary side of a transformer or to a connection point. Those detection sensors are not damaged since overvoltage is not applied to the voltage abnormality detector circuit when abnormal discharge occurs because the detection sensors are not electrically connected.

Abstract: An over-voltage protection circuit structure for protecting a high power translation circuit is provided. The over-voltage protection circuit structure receives an alternating current input and comprises a relay circuit, a voltage detection module, and an energy supply circuit. The relay circuit relays the alternating current input to the high power translation circuit. The energy supply circuit provides power to the voltage detection module in response to the alternating current input. The voltage detection module detects a voltage value of the alternating current input continuously. When the voltage value is greater than or equal to a first reference value, the voltage detection module generates an over-voltage signal. The relay circuit opens to cease delivering the alternating current input into the high power circuit in response to the over-voltage signal, thus the purpose of protecting the high power circuit is achieved.

Abstract: A safety switch device for switching a power supply for a load on and off, having at least one driveable switching element, in particular a relay, and a safety circuit for checking a switching state of the switching element. The switching element is in the form of a changeover switch in such a manner that a first contact is electrically connected to either a second contact or a third contact by means of a switching operation. A method for operating a safety switch device is also provided.

Abstract: A plurality of DC power supply modules have track pins interconnected for tracking of output voltages of the modules during power-up and normal power-down. Each module pulls down its track pin voltage in response to any fault, and detects a track pin voltage below a threshold to detect a fault communicated from any other module, to facilitate fault power-down. The track pin voltage is initially raised above the threshold for power-up. One module can be designated a master for monitoring an input voltage to the modules and for determining the track pin voltage for normal power-up and power-down.

Abstract: The invention is directed to a method for controlling a deceleration process of a DC motor (20), wherein the DC motor (20) is driven by a bridge driver (18) coupled to a power supply (12) intended to provide a supply voltage VDD at a power supply output (14), the method comprising the following steps: applying a deceleration PWM signal to the bridge driver (18) for decelerating the DC motor (20), and controlling the bridge driver (18) such that a motor-induced back current is reduced, if the voltage at the power supply output (14) exceeds a voltage threshold which is higher than VDD.

Abstract: A power supply control circuit includes a control circuit that controls an output transistor to be rendered conductive by forming a second electrical path between a second power supply line and a control terminal of the output transistor when a power supply voltage is applied in a reverse direction between first and second power supply lines, and that controls a second electrical path to be electrically disconnected when the power supply voltage is applied in a forward direction between the first and second power supply lines.

Abstract: A clock receiver (301) on an integrated circuit (202) includes a programmable AC voltage divider (502) for receiving, through an input capacitor (406), a clock signal (206) from a clock generator (204) off the integrated circuit and for outputting a modified signal that has a reduced voltage swing, an inverter (440) coupled to the programmable voltage divider, and a common mode setting circuit (506), coupled to an input and an output of the inverter. The common mode setting circuit sets and maintains a common mode at the input of the inverter in response to a voltage at the input of the inverter and a voltage at the output of the inverter. The strength of transistors in the common mode tracking circuit tracks the strength of transistors in the inverter such that the common mode at the input to the inverter tracks a trip point of the inverter.

Abstract: A multi-voltage biasing system with over voltage protection has an amplifier with a stage including at least one output device and one cascode protection device having a predetermined maximum recommended voltage; a biasing network is selectively responsive to a plurality of different supply voltages at least one of which is higher than the maximum recommended voltage for providing to the stage a bias voltage to operate the cascode device and output device below their maximum recommended voltages.

Abstract: A fan system is electrically connected to a power source, and the fan system includes a power reverse protection apparatus, a voltage regulator, a driver, and a fan. The power reverse protection apparatus, electrically connected to the power source, includes a voltage regulator switch and an activating device. The voltage regulator switch receives an input signal and outputs a first output signal according to the input signal. The activating device is electrically connected to the power source and the voltage regulator switch for receiving the input signal and the first output signal, respectively. The activating device outputs a second output signal to the fan according to the first output signal. The voltage regulator is electrically connected to the power source for receiving the input signal from the power source and outputting a regulating signal according to the input signal.

Abstract: A power supply circuit includes an energy-consuming component including an input terminal, an input over-voltage protection circuit connected to the input terminal, and a feed back circuit. The feedback circuit is connected to the input over-voltage protection circuit and the input terminal of the energy-consuming component. The feedback circuit monitors the voltage on the input terminal, compares the voltage on the input terminal with a reference voltage, and turns off the input over-voltage protection circuit to cut off voltage provided to the input terminal of the energy-consuming component when the voltage on the input terminal is larger than the reference voltage.

Abstract: The invention relates to a surge protector having a thermal separating device and an error display, and at least two first protection elements, particularly disk-shaped varistors (7), and at least one second protection element, particularly a gas arrester (9), wherein the first and the at least one second protection elements are switched in a Y arrangement, further comprising a device housing for accommodating the protection elements, and a means (11) for the mechanical biasing of the thermal separating device, wherein the thermal separating device has a low-melting solder, and the first protection elements (7) are disposed in the device housing such that a connection arm of a protection element (7) is positioned opposite the connection arm of the further protection element (7) at a distance, and the thermal separating device is predominantly positioned in the distance space (13) formed in such a manner.

Abstract: A risk of shock (ROS) protection circuit is disclosed, which comprises a capacitor that charges whenever there is a voltage between a ground on a lamp ballast and earth ground. If the capacitor exceeds a predetermined threshold voltage, the capacitor causes a gate to shunt current away from a tertiary winding in a control circuit, which in turn reduces impedance reflected by the tertiary winding back on to primary and secondary windings in the ballast circuit. The reduced reflected impedance causes the operating frequency of the ballast to increase, reducing the voltage between the ballast ground and earth ground until it is safe for human contact. In this manner, a human replacing a lamp connected to the ballast can be protected from shock despite a failure to disconnect the power to the lamp ballast prior to lamp replacement.

Abstract: An integrated apparatus is disclosed that can directly connect to a portable digital video camera and can record uncompressed video and audio data, along with associated metadata, in the field and elsewhere. Most preferably, the integrated apparatus includes a removable, recordable, reusable digital magazine that may be mounted. Most preferably, the integrated apparatus also supports a variety of input and output formats, and the apparatus may be easily connected to other computing systems, either directly or through network connections, wired or wireless. The digital magazine can be mounted in a variety of docking stations and can be directly connected to a network, allowing the video and audio data to be easily stored and transferred.

Abstract: A device for protecting sensitive electronic equipment from low level signal lines short circuited to high voltage power sources includes a switch that open the circuit between the data lines and the sensitive computing equipment if a high voltage condition is detected on the data lines. Otherwise, the switch remains closed and data can be transmitted to the computing equipment.

Abstract: An exemplary backlight control circuit includes a load (250), an inverter circuit (230), a pulse width modulation integrated circuit (PWM IC) (210), a protecting circuit (270), and a feedback circuit (240). The load (250) includes two backlight lamps (251, 252) with first terminals (241). The PWM IC with a protecting output (215) is connected to the load via the inverter circuit. The protecting circuit has a reference voltage. The first feedback circuit is capable of outputting a voltage to the protecting circuit corresponding to the voltage detected from the first terminals. The protecting circuit is configured to control the PWM IC to stop outputting a backlight adjusting signal to the inverter circuit such that the inverter circuit stops driving the load when the output voltage is higher than the reference voltage of the protecting circuit.