66results about How to "Expand the input range" patented technology

The invention relates to a photovoltaic cell -DC/DC boost conversion charge method which belongs to battery technique field. The method includes: 1) a portable equipment accumulator voltage is detected by a voltage sensor, when lows to full charge capacity, the voltage sensor makes DC/DC boost converter starting DC/DC conversion, and electricity quantity flows from photovoltaic current to lithium battery for charging; 2) when the portable equipment accumulator is in full charge capacity state, accumulator need not charge again, the voltage sensor makes DC/DC boost converter forbidding DC/DC conversion, thereby, the portable equipment accumulator is protected and over charge phenomena is prevented. The method can be realized simply, and has short reaction time, high efficiency, overvoltage protection and anti-counterblast protection.

The invention relates to an intelligent constant-current driver realized by an embedded chip and a control method of the intelligent constant-current driver. The intelligent constant-current driver realized by the embedded chip is characterized by comprising a rectifying filter module, a null-point detecting module, a DC (direct current)-DC conversion module, an overcurrent protection module, a double-limit-current control module, an MOS (metal oxide semiconductor) tube driving module, an embedded intelligent control module and a function extension module based on the embedded chip. The constant-current driver is large in input range, high in efficiency, upgradable, simple in circuit structure, adjustable in output current and rich in extended functions, and is an intelligent constant-current control system. Meanwhile, when the load is an LED array, light dimming, color changing and flickering control and the like can be realized by the system. Therefore, the intelligent constant-current driver can be used for realizing devices for LED lighting, LED alarm lamps and LED displaying and the like.

The invention is applicable to the field of LED lamps, and provides a buck chopper circuit, an LED drive circuit and an LED lamp, wherein the buck chopper circuit comprises a filtering unit, a first-stage voltage-reducing unit, a second-stage voltage-reducing unit and a control unit. In the embodiment of the invention, the buck chopper circuit is provided with the first-stage voltage-reducing unit and the second-stage voltage-reducing unit; and compared with the adoption of one-stage voltage reduction, the adoption of two-stage voltage reduction can greatly reduce the input voltage under the condition of the same duty cycle, therefore, compared with the adoption of the one-stage voltage reduction, the adoption of the buck chopper circuit can greatly increase the input scope of the voltage under the precise that the input voltage is constant.

A current-to-voltage converter which is used to receive an input current and to generate an output voltage accordingly comprises a current tracking bias circuit, a current-to-voltage unit, and a voltage clamp bias circuit. The current tracking bias circuit generates a first bias according to the input current. The current-to-voltage unit receives the first bias and the input current, and generates the output voltage according to the input current, wherein the first bias determines a range of the input current, the current-to-voltage unit has a first current control device, and the first current control device changes a current conduction level thereof in response to the first bias, such that a rising or falling speed of the output voltage is enhanced. The voltage clamp bias circuit clamps voltage levels of two ends where the voltage clamp bias circuit is connected to the current-to-voltage unit.

The invention discloses a low-power-consumption high-PSRR band-gap reference source. The low-power-consumption high-PSRR band-gap reference source comprises a first P-channel field-effect transistor, a second P-channel field-effect transistor, a third P-channel field-effect transistor, a fourth P-channel field-effect transistor, a fifth P-channel field-effect transistor, a sixth P-channel field-effect transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, a first double-polar-form transistor, a second double-polar-form transistor and a voltage feedback circuit. By adopting the double-layer current mirror structure and adding a biasing resistor, the influence of the channel length modulation effect between current mirrors is reduced, the accuracy of a current multiplication factor is guaranteed, and then detuning of output voltage is reduced.

The present invention belongs to the field of analog signal treatment and communication technology and relates to variable-gain amplifier. The variable-gain amplifier includes several cascaded basic variable-gain units and one control voltage generator connected to the variable-gain units. The variable-gain amplifier features that basic variable-gain unit comprising several parallelly connected multi-stage stacked resistor-degenerate MOS pairs and two load resistors connected to the degenerate MOS pairs. The present invention may be realized via CMOS technological process and has the advantages of great controlled-voltage range, linear gain, great dynamic range, low working voltage and low power consumption.

The invention relates to the field of analog integrated circuit design of microelectronics, and provides a cyclic time to digital convertor (Cyclic TDC) in order to further expand an input range of the traditional TDC, allow the TDC to maintain the linear characteristic in a larger input range, and reduce a design matching requirement. The cyclic TDC adopts the technical scheme that a difference value of two input time signals is converted into corresponding digital codes by a sub TDC; a time margin obtained by conversion of the sub TDC is amplified by a time 2* magnifier; the amplified time margin enters the sub TDC for quantization through a multiplexer; a cyclic conversion process is performed to the required precision; the converted digital codes are subjected to dislocation addition by a reading circuit; and the obtained final digital code is output by the reading circuit, so that the conversion from the time signals to the digital codes is accomplished. The cyclic TDC is mainly applied to the analog integrated circuit design.

The invention discloses an avalanche photo diode (APD) bias voltage adjustment circuit based on negative voltage adjustment. The circuit includes a pixel outside bias voltage generating module and a pixel inside bias voltage adjustment module. The pixel outside bias voltage generating module uses a first operational amplifier and a second operational amplifier to clamp source voltages of a secondPMOS tube and a fourth PMOS tube to stepping voltage and 0V. The pixel inside bias voltage adjustment module uses a first current mirror unit and a first PMOS tube in the pixel outside bias voltage generating module to form a proportional current mirror structure, different proportions of mirroring are realized through controlling switches, and thus floating ground voltage is adjusted to an integer multiple of the stepping voltage. The pixel inside bias voltage adjustment module uses a second current mirror unit and a third PMOS tube in the pixel outside bias voltage generating module to forma current mirror structure, the floating ground voltage is clamped to 0V when all the switches in the first current mirror unit are turned off, and stepping adjustment of APD bias voltage is realized.A manner of negative voltage adjustment is adopted to expand an adjustment range of the APD bias voltage, and improvement of detection sensitivity of an APD array is facilitated.

The invention relates to the field of analog integrated circuit design of microelectronics, in particular to a wide-input-range linear voltage-to-time conversion method and a wide-input-range linear VTC, wherein the wide-input-range linear voltage-to-time conversion method and the wide-input-range linear VTC aim to enlarge the input range of a traditional VTC and enable the VTC to keep the linear characteristic within the large input range. According to the technical scheme, the wide-input-range linear VTC comprises two sampling switches Sh, two discharge switches Sd, two sampling capacitors CH or CL and Cref, two current sources I and two comparators Com1 and Com2, wherein H represents the word of high, and L represents the word of low. The two sampling switches Sh are turned on, and two sets of input analog voltage signals are sampled through the sampling capacitors CH or CL and Cref; then the sampling switches Sh are turned off, the discharge switches Sd are turned on, and accordingly the sampling capacitors CH or CL and Cref are discharged within the specified time; the comparators Com1 and Com2 detect voltage at the two ends of each capacitor and compare the voltage with a comparison signal. The wide-input-range linear voltage-to-time conversion method and the wide-input-range linear VTC are mainly applied to the analog integrated circuit design.

The adaptive output driver of white light LED comprises: connecting drive tube (Q) with control end and output end to output drive end (1) with inlet connected outlet of PWM controller (3) and the output control circuit (2), negative ends of the induction coil (L) and diode (D), respectively; paralleling an output capacitor (Cout), a load resistance (RL), and two serial first and second feedback resistances (Ra and Rb) between diode poles; connecting another end of (Q) to power (VIN), connecting inverse-phase inlet of (3) to outlet of error amplifier (4) with inlet linked to the joint point of said feedback resistors, and in-phase inlet to startup module (5) and oscillator (6).

A piezo electric element generates a vibrating voltage in response to a striking force on a pad. The piezo electric element is connected across a series connection of a linear resistor and a nonlinear resistance network. The voltage appearing across the nonlinear resistance network is taken as an output voltage. The nonlinear resistance network is comprised of a parallel connection of a first and a second resistance circuitry. The first resistance circuitry is a series connection of a resister and two diodes connected in parallel in an opposite polarity to each other. The second resistance circuitry is a series connection of another resister and two Zener diodes connected in series in an opposite polarity to each other.

The invention discloses an isolated bidirectional active full-bridge DC-DC converter, which is realized through series connection of two transformers and parallel connection of two full-bridge output ends at a low-voltage side based on an isolated bidirectional active full-bridge converter. Switching tubes in the corresponding positions in two full-bridge circuits at the low-voltage side of the converter are synchronously switched on and off. The on-off of the ninth switching tube K1 and the tenth switching tube K2 is determined by the proportion of the high-voltage side and the low-voltage side. Through a method of series connection and voltage division of the transformers at the primary sides of the transformers, the voltage input range of the primary sides of the transformers can be increased; and through a method of parallel shunting at the secondary sides of the transformers, the loss of the switching tubes is reduced, so that the loss of the whole circuit is reduced, and thus the circuit has relatively high energy conversion efficiency in an occasion of a relatively large voltage transformation ratio.

An integrating amplifier on an IC, which comprises a feedback loop using an external device as an integrating capacitor, has added a second feedback loop that provides an additional current to the input of the amplifier, which current can be used to increase the input range of the charge that can be measured without needing another external capacitor or pad.

The invention discloses an alternating current LED (Light Emitting Diode) driving circuit which comprises four rectifier diodes, a constant current diode and k sets of LED units in parallel connection, wherein a full-bridge rectifier circuit is formed by the four rectifier diodes; AC1 and AC2 are bridge type rectification inputs; and a bridge type rectification output is a circuit which is formed by the constant current diode in serial connection with k parallel LED units composed of n serially connected LEDs. According to the alternating current LED driving circuit provided by the invention, four rectifier diodes and one constant current diode are used for driving an LED, so that the use ratio of the LED reaches 100%, the lighting effect is increased and the cost is lowered.

The invention discloses a switching power circuit for power supply of a three-phase electric energy meter. The switching power circuit comprises an EMI (electromagnetic interference) unit, a rectifier filter unit, a high-frequency transformer, a PWM (pulse width modulation) control unit, a sampling unit, a rectifier output filter unit and a constant voltage output unit, an output end of the EMI unit is connected with an input end of the rectifier filter unit, an output end of the rectifier filter unit is connected with an input end of the high-frequency transformer, a first output end of the high-frequency transformer is connected with an input end of the rectifier output filter unit, a second output end of the high-frequency transformer is connected with an input end of the constant voltage output unit, an output end of the constant voltage output unit is connected with an input end of the sampling unit, an output end of the sampling unit is connected with an input end of the PWM control unit, and an output end of the PWM control unit is connected with a controlled end of the high-frequency transformer. The high-frequency switching power circuit can supply two paths of independent 12V power for the three-phase electric energy meter, and has the advantages of high efficiency, wide input range, high stability, high reliability and the like as compared with a traditional linear power supply.

The invention provides an isolating switch regulated transformer wave band superposing, rectifying and outputting circuit. The circuit is endowed with a new function by using the unidirectional switching-on characteristic of a rectifying diode of a direct current/direct current (DC/DC) converter, and a standby winding of a transformer and a standby diode connected in series with the standby winding are connected in parallel with the original rectifying diode through an isolating switch and connected in series with a basic winding of the transformer simultaneously, so that the output turn number can be changed when necessary, and the DC/DC converter can meet the requirement of a wider input voltage range. By the circuit, the problem that the DC/DC converter with a wide input range has low efficiency, reliability and stability at the present stage is solved, and a jump-free, high-efficiency and reliable isolating switch regulated transformer segmented rectifying and outputting technicalscheme is provided.

The invention discloses a body driving structure micro display pixel circuit and solves a problem that the input data voltage range of a pixel circuit in an OLEDoS micro display is small in the priorart. The pixel circuit comprises a switch level, an intermediate level and a lighting level, wherein the switch level is connected with the intermediate level, the intermediate level is connected withthe lighting level, the switch level comprises a switch transistor, the intermediate level comprises a first adjusting transistor, a second adjusting transistor and a storage capacitor, the lightinglevel comprises a driving transistor and a light emitting diode, the voltage is transmitted by the switch level to the intermediate level in the circuit work process and is then adjusted by the intermediate level, after the width range is enhanced, the voltage is transmitted to the lighting level. The pixel circuit is advantaged in that the input range of the data voltage can be broadened, and thereby the higher gray scale level and high-precision and high-quality display can be realized.

There is provided a pipeline type A/D converter capable of expanding an input range and increasing the number of bits of digital output signals, without increasing thermal noises or an open loop gain needed for an operational amplifier. The number of sample-hold capacitors is divided from M into N and further multiplies the reference voltage by N to increase the number of capacitors available to add to and subtract from the reference voltage. Consequently, it enables expanding the input range and increasing the number of bits of the digital output signals. On this occasion, the thermal noises are not deteriorated before and after the division of the capacitors, as the analog signal is sampled by all the capacitors. Further, the open loop gain needed for the operational amplifier will not be increased, since the ratio of the capacitors each used as a feedback element for amplifying the analog signal to the remaining capacitors is unchanged before and after the division of the capacitors.

The invention discloses a card reader for an access control system and a working method thereof. The card reader comprises a power module which supports 4.5-15V wide voltage input scope and can solve the problem of unstable long-distance power supply of the card reader; the card reader comprises a MCU module which has a dual encryption algorithm; after a physical card number is acquired by the card reader, the card reader calculates a password of a fan zone I, reads the content of the fan zone, calculates a password of a fan zone II again and then reads the fan zone content and calculates the card number, so that the safety of the access control system is promoted; the card reader comprises a pin protecting module; a pin input end has a high-voltage protection function and can prevent the elements from being burned if a worker mistakenly connects wires or gets electric shock by mistakenly touching high voltage in the mounting process. The card reader for the access control system not only can read cards but also can write cards, supports various communication transmission protocols of Wiegand 26, Wiegand 34 and Wiegand 44 simultaneously, has an increased capacity for acquiring card numbers, can prevent IC card copying function and can effectively eliminate the label cloning behavior.

The invention belongs to the field of flyback switching power supply design of a PWM control circuit. The power supply uses an enhanced voltage dependent resistor, secondary voltage dependent clampingstep down, and a high-voltage MOS voltage divider circuit to realize triple lightning surge protection in a wide power input range. The output signal of the flyback power supply is adjusted by an optocoupler feedback, and then is transferred to a PWM control IN circuit so as to further control a PWM duty cycle to drive a MOSFET power transistor, and then control the output of the flyback transformer to complete closed-loop control and supply power to the control IC. In the operation of the power supply, the fusion of capacitor [pi]-type filtering (CLC) and frequency-jittering technology can not only improve electromagnetic interference (EMI) in a wide range of high and low frequency bands, but also disperse the prominent harmonic components of the switching frequency and effectively reduce its EMI and output ripple noise, thereby meeting the requirements of the flyback power supply for stable and reliable operation in harsh environments.

Provided is a transformer (1), which includes: a core (10) which forms a magnetic circuit and has a middle leg (10a) and a plurality of side legs (10b, 10c) branched from the middle leg (10a); primary windings (11) respectively wound around a first winding leg (10a) and a second winding leg (10b), which are selected from the middle leg (10a) and the side legs (10b, 10c); and a secondary winding (12) wound around either of the first winding leg (10a) or the second winding leg (10b), wherein a first magnetic flux generated by the primary windings (11) from the first winding leg (10a) and a second magnetic flux generated by the primary windings (11) from the second winding leg (10b) differ from each other by a predetermined value or more at a position at which the fluxes do not intersect with the secondary winding (12).