13 results about "Voltage range" patented technology

A level of a base band signal at an input side of a variable gain amplification circuit is detected by a logarithmic amplifier having a wide input voltage range at a start of an operation, a control unit then performs a coarse feedforward control on a gain of the variable gain amplifier based on the detected level and finds a level of an output of an A/D converter by a mean square deriving circuit and inputs the resulting signal to the control unit. Then the control unit performs a fine feedback control on the variable gain amplifier based on the detected level.

The invention provides a power switch circuit system comprising an intelligent power module which comprises an upper bridge arm driving chip, a lower bridge arm driving chip and a power switch devicecomposed of a plurality of insulated gate bipolar transistors (IGBTs) located on a plurality of bridge arms, wherein the IGBT on each bridge arm comprises an upper bridge arm IGBT connected with the upper bridge arm driving chip, and a lower bridge arm IGBT connected with the lower bridge arm driving chip; a protection circuit externally connected to the output end of the upper bridge arm drivingchip and the output end of the lower bridge arm driving chip in the intelligent power module, wherein the protection circuit comprises a voltage stabilization protection circuit used for stabilizing the voltage of the output ends within a set voltage range; and/or a current stabilization protection circuit used for bypassing the displacement current of the output end to a ground wire. According tothe invention, the voltage stabilization protection circuit and/or the current stabilization protection circuit can be connected in the IPM module, the grid oscillation and parasitic conduction are reduced, and the utilization rate and reliability of the device are improved.

The invention provides an LED (Light-Emitting Diode) unit and a constant-flow unit voltage-stabilizing LED control circuit. The constant-flow unit voltage-stabilizing LED control circuit comprises a rectifier bridge, at least one LED control unit series branch and at least one current limiting resistor, wherein the rectifier bridge is connected with a power supply, and the LED control unit series branch is connected with the rectifier bridge. The constant-flow unit voltage-stabilizing LED control circuit utilizes the forward voltage drop characteristic of a voltage stabilizing tube and a diode, the voltage-stabilizing role of the full unit is played. The control mode is cheaper and more practical, and the efficiency is higher. In addition, when the voltage of the power supply is lower than the normal power supply voltage, as the full circuit works in a working state lower than a voltage stabilizing value, the lower voltage is uniformly shared by the voltage-stabilizing circuits of the full unit, the brightness of all LEDs is uniformly reduced, and therefore the continuous dimming function can be realized in a certain voltage range. Practices prove that the full circuit can reliably work in the voltage range of AC (Alternating Current)/DC (Direct Current) 120V to 270 V.

A driver utilizes selective biasing of the terminal of an operational amplifier to reduce offset in the operational amplifier output. Each operational amplifier input includes a differential input pair of transistors including a NMOS transistor and PMOS transistor. At low and high ends of the input voltage range these transistors are selectively and individually coupled to either a standard input or biased to be on so as to contribute offset for offset compensation. The transistors are biased in a conventional manner for input voltages between the low and high ends of the voltage range.

A charger includes a charging port for receiving an electrical signal input from an adapter. The charger further includes a detection unit electrically connected to the charging port and a control unit electrically connected to the detection unit. The detection unit detects an input voltage and an input current of the charger. The control unit judges whether the input voltage of the charger is within a preset voltage range, and when the input voltage of the charger is judged to be within the preset voltage range, the control unit controls the input current of the charger to gradually increasein a preset manner until the charger inputs maximum power so as to charge the charger. The invention also provides a charging method of a charger. By utilizing the invention, the input current level of the charger can be gradually increased until the charger inputs the maximum power, and the maximum power output of the adapter can be realized on the premise of guaranteeing the safety of the adapter.

The invention relates to a micromotor capable of extending voltage applicable scope, in particular to a micromotor capable of extending the voltage applicable scope of a mini-type small-power single-phase series motor or a permanent magnet DC motor. The micromotor capable of extending the voltage applicable scope comprises a motor, wherein the motor is provided with a voltage reducing device, and the voltage reducing device is connected with the motor in series. The voltage reducing device comprises a voltage reducing resistor, wherein the voltage reducing resistor is connected with the motor in series, and the voltage reducing resistor can divide the voltage when a power source is applied to the pressure reducing resistor and the motor, so that the scope of power supply voltage applied to the motor is extended and the steering sparkle of the motor is improved. By changing the resistance of the voltage reducing resistor, the motor can be applied to different voltage applicable scope and is convenient in installation and operation. The voltage reducing resistor is provided with a saw-toothed heat dissipating device, so that the micromotor can effectively dissipate the heat of the voltage reducing resistor, guarantees the use security of the voltage reducing resistor, and prolongs the service life of the voltage reducing resistor.

The invention relates to a computer liquid cooling source heat dissipation control module. A base clamp slot is fixed at one end of a bottom of an outer side of a valve base. A valve plate inner cavity is set in the valve base. An intra-cavity slot is set at the center position of the valve plate inner cavity. An electromagnetic ring a and an electromagnetic b are set at left and right sides of the intra-cavity slot. The electromagnetic ring a and the electromagnetic b are connected with electrode wiring terminals. An air bag column is clamped and fixed at the central position between a valvebottom plate and a valve top plate. An iron sheet disk is placed in the valve top plate. According to the module, a direct current voltage range input by the electromagnetic ring a and the electromagnetic b is 3.6-12V. Input voltages can be linearly adjusted and controlled in real time. When the direct current voltages input by the electromagnetic ring a and the electromagnetic b are peak values,the space between the valve bottom plate and the valve top plate is the limit lowest space. The computer liquid cooling source heat dissipation control module is prepared.

The invention discloses a photovoltaic under-power output control method. The method comprises the following steps: (1) acquiring a current output voltage vpv and a current output current ipv of a photovoltaic array; (2) calculating a value of dp/dv, and determining a photovoltaic working voltage range by adopting dp/dv control; and (3) adding constant voltage control on the basis of dp/dv control, and determining the photovoltaic power hot standby operation voltage according to the voltage range obtained by dp/dv control. By means of the method, equal-proportion hot standby of the output power of the photovoltaic power supply at different temperatures and irradiance can be achieved, temperature and irradiance sensors are not needed, existing hardware resources are efficiently utilized, and the photovoltaic power supply can be conveniently transplanted into a current photovoltaic system.

The invention discloses a method for calibrating a low-dropout linear voltage stabilizer. According to the method, firstly, when an LDO trimming value is stored in flash, an LDO secret key is stored at the same time; after power-on, the LDO secret key is read from flash, and whether LDO output voltage is adjusted or not is determined according to whether the read LDO secret key is correct or not; when the read LDO secret key is incorrect, the LDO output voltage is adjusted into LDO_VDD through the dichotomy; when the correct LDO secret key is read, it is considered that the LDO output voltage can support normal reading of flash, then the LDO trimming value stored in flash is read, and the LDO output voltage is adjusted into a voltage center value; normal work starts. By means of the method, a chip with initial LDO output voltage beyond the voltage range required by normal work of flash can work normally, the chip yield can also be increased, and cost is reduced.

Some aspects of the present disclosure relate to an apparatus, a PLL and an electronic device. The apparatus comprises a voltage-to-current (V2I) converter, a current controlled oscillator and a compensation current. The V2I converter is operable to receive a first voltage and generate a first current based on the first voltage. The current controlled oscillator is coupled to the V2I converter and operable to generate an oscillation signal based on a second current from or to the V2I converter. The compensation circuit is coupled to the V2I converter and operable to receive a third current from or to the V2I converter. The second and third currents vary in response to at least one of temperature variation and supply voltage variation of the apparatus. Variation direction of the third current is opposite to variation direction of the second current and different frequencies may be provided for a low supply voltage domain.