100 results about "Farad" patented technology

The present invention provides a low dropout (LDO) regulator with a stability compensation circuit. A “zero frequency” tracking as well as “non-dominant parasitic poles' frequency reshaping” are performed to achieve a good phase margin for the LDO by means of the compensation circuit. In this compensation method neither a large load capacitor nor its equivalent series resistance is needed to stabilize a regulator. LDO regulators, in system on chip application, having load capacitors in the range of few nano-Farads to few hundreds of nano-Farads can be efficiently compensated with this compensation method. A dominant pole for the regulator is realized at an internal node and the second pole at an output node of the regulator is tracked with a variable capacitor generated zero over a range of load current to cancel the effect of each other. A third pole of the system is pushed out above the unity gain frequency of the open loop transfer function with the help of the frequency compensation circuit. The compensation technique is very effective in realizing a low power, low-load-capacitor LDO desirable for system on chip applications.

A method of pumping fluid including the steps of providing an electrokinetic pump comprising a pair of double-layer capacitive electrodes having a capacitance of at least 10−2 Farads / cm2 and being connectable to a power source, a porous dielectric material disposed between the electrodes and a reservoir containing pump fluid; connecting the electrodes to a power source; and moving pump fluid out of the reservoir substantially without the occurrence of Faradaic processes in the pump. The invention also includes an electrokinetic pump system having a pair of double-layer capacitive electrodes having a capacitance of at least 10−2 Farads / cm2; a porous dielectric material disposed between the electrodes; a reservoir containing pump fluid; and a power source connected to the electrodes; the electrodes, dielectric material and power source being adapted to move the pump fluid out of the reservoir substantially without the occurrence of Faradaic processes in the pump.

The present invention provides a low dropout (LDO) regulator with a stability compensation circuit. A “zero frequency” tracking as well as “non-dominant parasitic poles' frequency reshaping” are performed to achieve a good phase margin for the LDO by means of the compensation circuit. In this compensation method neither a large load capacitor nor its equivalent series resistance is needed to stabilize a regulator. LDO regulators, in system on chip application, having load capacitors in the range of few nano-Farads to few hundreds of nano-Farads can be efficiently compensated with this compensation method. A dominant pole for the regulator is realized at an internal node and the second pole at an output node of the regulator is tracked with a variable capacitor generated zero over a range of load current to cancel the effect of each other. A third pole of the system is pushed out above the unity gain frequency of the open loop transfer function with the help of the frequency compensation circuit. The compensation technique is very effective in realizing a low power, low-load-capacitor LDO desirable for system on chip applications.

An optoelectronic semiconductor device is disclosed wherein the device is a vertical-cavity surface-emitting laser or a photodiode containing a section, the top part of which is electrically isolated from the rest of the device. The electric isolation can be realized by etching a set of holes and selective oxidation of AlGaAs layer or layers such that the oxide forms a continuous layer or layers everywhere beneath the top surface of this section. Alternatively, a device can be grown epitaxially on a semi-insulating substrate, and a round trench around a section of the device can be etched down to the semi-insulating substrate thus isolating this section electrically from the rest of the device. Then if top contact pads are deposited on top of the electrically isolated section, the pads have a low capacitance, and a pad capacitance below two hundred femto-Farads, and the total capacitance of the device below three hundred femto-Farads can be reached.

A pest deterrent device attracts the attention of a pest with ultrasonic noise and then produces a series of flashes to drive off the pest. In one embodiment, the device continuously produces ultrasound, changing the ultrasound when a pest is detected. In another embodiment, the device does not produce ultrasound until a pest is detected. In a further embodiment, the flash charging circuit is used to modulate the ultrasound while the flash is operated. In a particular embodiment, four ultrasonic speakers are arranged in a series-parallel configuration with a total capacitance of about 0.2 micro-Farads achieve 120 dB of sound output with a supply voltage of about 12-18 V.

An electric double layer capacitor is composed of a pair of current collectors, a positive polarizable electrode provided on one of the pair of current collectors, a negative polarizable electrode provided on the other of the pair of current collectors, a separator between the positive and negative polarizable electrodes, and an organic electrolytic solution which impregnates at least the positive and negative polarizable electrodes and the separator. The capacitor has a theoretical amount of ions Qt defined asQt (moles)=C×V÷96,500,wherein C is the rated capacitance (farads) of the capacitor and V is the rated voltage (volts), and an amount of ions Qe in the organic electrolytic solution, such that Qe / Qt=1.7 to 3.5. The capacitor has a high voltage rating, excellent cycle characteristics during high-current charging and discharging, and a low internal resistance in low-temperature environments.

A capacitance charge device with adjustable clamping voltage is disclosed in the invention, which includes a high-farad capacitance and a power supply device for charging to the high-farad capacitance. In addition, a switch device is connected between the power supply device and the capacitance, and through the on / off operations of the switch device, the on / off conductions between the power supply device and the capacitance can be controlled. Besides, a clamping circuit is connected between the switch device and the capacitance and also connected to the output terminal of the power supply device. In addition, the clamping circuit has a clamping voltage, which can be compared with the actual voltage so as to control the on / off operations of the switch device and in turn control the on / off conductions between the power supply device and the capacitance. In addition, the invention can constrain the battery voltage in the clamping voltage of the clamping circuit. By doing so, the system can be ensured not to be down because of a sudden tremendous voltage drop of the battery, and the clamping voltage is adjustable according to the variations in product design.

Exemplary embodiments of the present disclosure include dipole arrangement, or an array of dipole arrangements which can include at least two poles extending in opposite direction from one another, each of the poles including capacitor and an inductor(s). A lattice balun can be located at a center gap between the poles, and can be a 50 ohm lattice balun. The capacitor(s) can be a 10.67 farad capacitor. The inductor can be a 26.7 Henry inductor. The length of each of the poles can depend on a wavelength of a magnetic field generated by the dipole arrangement, or it can depend on a distance from the dipole arrangement to a subject to be imaged.

The invention relates to an ultra-mobile power supply. The ultra-mobile power supply is characterized in that the ultra-mobile power supply comprises a rectifying circuit, an energy control circuit, a rectifying output circuit, a protection circuit, a DC-DC limiting circuit, a farad capacitor and a voltage stabilization output circuit, the input end of the rectifying circuit is connected with the electric supply, the output end of the rectifying circuit is connected with the input end of the energy control circuit, the input end of the rectifying output circuit is connected with the output end of the energy control circuit, the output end of the rectifying output circuit is connected with a connecting pin of the farad capacitor, and therefore the electric supply input charge structure is formed; the DC-DC limiting circuit is provided with a USB input end, the output end of DC-DC limiting circuit is connected with a connecting pin of the farad capacitor, and therefore a USB input charge structure is formed; the input end of the protection circuit is connected with the output end of the rectifying circuit, the second output end of the energy control circuit and the feedback signal output end of the energy control circuit, the output end of the protection circuit is connected with the control input end of the energy control circuit, and therefore a feedback control structure of the energy control circuit is formed. Due to the fact that the super capacitor energy storage structure is formed, the ultra-mobile power supply has the advantages of being quite high in charge speed, high in efficiency, safe and reliable.

The invention provides a laptop with a power failure protection module, and relates to the technical field of computers. The laptop comprises an adaptor, a battery charging-discharging module and a laptop main board. The laptop has the structural characteristics that the laptop also comprises the power failure protection module consisting of a control circuit, a charging circuit, a farad-class energy storage capacitor and a discharging circuit which are connected in series in sequence. By the adaptor, the commercial power supplies direct voltage to power a power supply mode detection circuit in the laptop main board and simultaneously charges the battery charging-discharging module and the power failure protection module; and the outputs of the battery charging-discharging module and the power failure protection module are connected with the power supply mode detection circuit respectively. Compared with the prior art, the battery charging-discharging module can be replaced without being powered off, simultaneously avoid the influences on the normal work of a user due to power failure and provide the high-quality power for the computer system.