Negative impedance converter

About: Negative impedance converter is a research topic. Over the lifetime, 5801 publications have been published within this topic receiving 87636 citations.

Frequency feedback on a current loop of a current-to-pressure converter

Abstract: A current-to-pressure (I/P) converter (20) provides an output pressure as a function of the magnitude of a variable input DC current. The I/P converter (20) includes a pressure sensor (64) which produces a feedback signal representative of the output pressure. Based upon the feedback signal and the magnitude of the input DC current, an electrical control signal is produced which controls a device (40) for varying the output pressure. The I/P converter (20) also includes a circuit (86) for generating a time-varying signal which is sent back over the current loop wires (28) through which the input DC current flows. The time-varying signal provides an indication of whether the I/P converter (20) is functioning properly. This permits diagnosis of possible causes of control system malfunctions without having to inspect the I/P converter (20) itself.

Multiphase Power Converter Circuit and Method

Abstract: A multiphase power converter circuit includes at least two single phase power converter circuits. Each single phase power converter circuit includes at least one converter series circuit with a number of converter units. The converter series circuit is configured to output a series circuit output current. A synchronization circuit is configured to generate at least one synchronization signal. At least one of the converter units is configured to generate an output current such that at least one of a frequency and a phase of the output current is dependent on the synchronization signal.

System and method to establish an adjustable on-chip impedance

Abstract: A method to establish an adjustable on-chip impedance within a predetermined range that involves establishing a reference current for the adjustable on-chip impedance and applying this reference current to the adjustable on-chip impedance. A voltage produced by applying the reference current to the adjustable on-chip impedance is sensed and compared with the comparator or other similar processor to a reference voltage. This comparison allows the adjustable on-chip impedance to be tuned when the comparison of the sense voltage and the reference voltage is unfavorable. Tuning the impedance results in an impedance value within a predetermined range that accounts for variances of both the reference current and reference voltage.

Dual active bridge DC-DC converter using both full and half bridge topologies to achieve high efficiency for wide load

Abstract: This papar proposes which the Dual Active Bridge (DAB) converter changes between Full Bridge (FB) converter's operation and Half Bridge (HB) converter's operation on the secondary side of the high frequency transformer depending on the output power. With the HB converter operation's, the iron loss of the transformer becomes small because the secondary voltage of the transformer becomes half compared to the FB converter's operation. In addition, Zero Voltage Switching (ZVS) is achieved at the light load. Therefore, the proposed circuit can obtain the high efficiency for the wide load by the changing the HB and the FB converter's operation depending on the output power. In this paper, the changing point between the HB and the FB converter is derived using the loss calculation. The validity of the proposed circuit is verified by 800-W prototype. From the experimental results, it is confirmed that the proposed circuit has the two local maximum efficiencies which are 92.9% and 93.4% at the light load and the heavy load using the proposed circuit.

Battery charger and method for collecting maximum power from energy harvester circuit

Abstract: An energy harvesting system for transferring energy from an energy harvester ( 2 ) having an output impedance (Z i ) to a DC-DC converter ( 10 ) includes a maximum power point tracking (MPPT) circuit ( 12 ) including a replica impedance (Z R ) which is a multiple (N) of the output impedance. The MPPT circuit applies a voltage across the replica impedance that is equal to an output voltage (V in ) of the harvester to generate a feedback current (I ZR ) which is equal to an input current (I in ) received from the harvester, divided by the multiple (N), to provide maximum power point tracking between the harvester and the converter.