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US 6,486,643 B2Granted
High-efficiency H-bridge circuit using switched and linear stages
AssigneeAnalog Technologies, Inc.
InventorGang Liu
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AssigneeAnalog Technologies, Inc.
InventorGang Liu
Estimating the term…
An H bridge regulating system for driving an electric load includes a linear output stage and switch mode output stage connected to opposite ends of the load. The linear output stage has a linear mode amplifier and a feedback circuit, and its amplifier generates a first output signal tied to one end of the load. This output voltage is passed through a conditioning resistor to an inverting input of the linear mode amplifier. The switch mode output stage has a switch mode amplifier and a feedback circuit, and its amplifier generates a second output signal tied to the other end of the load. Its voltage signal is passed through a second conditioning resistor to an inverting input of the switch mode amplifier. Other feedback circuit elements are also provided to create three distinct regions of operations for each of the amplifiers. Due to this novel arrangement for an H bridge circuit, and this novel method of operation involving three distinct regions of operation for the linear mode and switch mode output stages, very high power-saving energy efficiencies are achieved. In addition, H bridge systems for three terminal electrical devices such as three-phase electric motors are disclosed.
An H bridge regulating system for driving an electric load, the H bridge system comprising:
An electronic control system for driving an electric load having at least two terminals in a regulated manner, the control system including an H bridge arrangement for driving the electric load, the electronic control system comprising:
A method of driving an electric load, using an H bridge system, in proportion to a value of an input command signal, the method comprising the steps of:
An electronic control system including a H bridge arrangement for driving an electric load having three terminal ends, each of which are to be driven, the electronic control system comprising:
An electronic control system including a H bridge arrangement for driving an electric load having three terminal ends, each of which are to be driven, the electronic control system comprising:
Dependencies are inferred from the claim text.
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From the US filing history. Foreign family members aren’t listed.
Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements: modifications of…
In a bridge configuration: with automatic control of output voltage or current
With semiconductor devices only: using a combination of several amplifiers
Details of apparatus for conversion: converters combining the concepts of switch-mode regulation and linear regulation, e.g. linear pre-regulator…
Term ended 27 Aug 2021 (estimated)
1. Technical Field
The present invention relates generally to H-bridge systems and methods for driving electric loads, and more particularly to high-efficiency H-bridge regulating circuits and methods for driving an electric load such as a thermoelectric cooler (TEC) by using a linear amplifier to drive one end of the load and a switching amplifier to drive the other end of the load.
2. Discussion
FIG. 1 is a schematic diagram of a conventional (prior art) high efficiency H bridge using two switch-mode output stages to drive an electric load, such as a TEC, positioned therebetween.
FIG. 2 is an embodiment of the present invention for a high efficiency H bridge system using one linear output stage and one switch mode output stage.
FIGS. 3A-3C show signal wave forms as a function of input voltage Vinput, which help explain the operation in the H bridge system of FIG. 2, where:
The following description of the preferred embodiments of the H bridge systems and methods of the present invention are merely exemplary in nature and are in no way intended to restrict the scope of the present invention, the manner in which various aspects of the invention can be implemented, or their applications or uses. For example, although the invention is first discussed with respect to resistive loads, it should be understood that the invention can also be used with electrical loads having one or more reactive components as well, including but not limited to motor loads, capacitive loads, and inductive loads.
By way of introduction and laying out further background, FIG. 1 shows the basic construction of a prior art H bridge circuit 100 that uses two conventional output stages 105 and 115, each including an identical amplifier 110 or 120. These two amplifiers are each schematically shown as an operational amplifier having high-impedance inverting and non-inverting inputs and a single central or center-tapped output 111 or 122. The first output stage 105 includes a feedback circuit comprising of a conductor 107 running the first output 111 to the inverting input of amplifier 110. An input command signal Vin is supplied to the noninverting input of amplifier 110. The second output stage 115 also includes a feedback circuit comprised of conditioning elements R11 and R22, which preferably are resistors, connected as shown. Resistor R11 is connected at one end to the second output 122, and at the other end to inverting input of amplifier 120. Input command signal Vin is connected to the inverting input of amplifier 120 through element R22 as shown at node 124. Node 124 is a summing junction in that the relative strength of the signals reaching the inverting input of amplifier 120 is determined by the relative values of conditioning elements R11 and R22.
The amplifiers 110 and 120 can each be implemented using two power switching devices such as power bipolar junction transistors (BJTs), or such as power MOSFETs, in their output stages, and low power components, such as operational amplifiers, ASICs or other integrated circuit chip or hard-wired circuits for all other parts of the amplifiers. Each power BJT may be each implemented as a Darlington pair of transistors. The power switching devices in each amplifier are arranged in a conventional push-pull configuration. In other words, within each amplifier, the power BJTs or MOSFETs are arranged in series between the positive and negative power supply rails denoted as Vps and −Vps in FIG. 1. As is well known, the series pair of power BJTs or MOSFETs in amplifiers 110 and 120 are then each center-tapped. This provides first and second outputs 111 and 122 which are then each connected to opposite ones of the two wires of electric load 130 as shown. Load 130 may be a TEC or any other kind of load. Using Kirchhoff's law, the current will flow through the load depending upon what the relative output (e.g., voltage) of the first amplifier 110 is to the output (e.g., voltage) of the second amplifier 120. The structure of the overall H-bridge circuit looks like an H when viewed at a distance, hence its name.