Following voltage/current regulator
First Claim
1. A voltage/current regulator for supplying regulated voltage from an unregulated source to a bridge and motor load and limiting an inrush current to the load comprising:
- a transistor connected in series with said load, said transistor including first and second current conducting electrodes and a control electrode; and
control circuit means connected to said control electrode for controlling the conduction of said current conducting electrodes, said control circuit means including current limit feedback means for limiting the current drawn by said load, said control circuit means including bypass means to prevent said transistor from supplying bridge ripple current to said unregulated source.
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Accused Products
Abstract
A following voltage/current regulator includes a field effect transistor (FET) (48) connected in series between an unregulated voltage source (44) and a load, such as a motor bridge circuit (50). The conduction of the FET is controlled by a control circuit (56) which measures the input voltage to the FET source, the output voltage from the FET drain and the current drawn by the load. Initially, when power is turned on, the inrush current to the load is limited until a predetermined voltage differential between the input and output voltages is achieved at steady state. Then, the voltage regulator maintains the predetermined voltage differential to provide a well regulated output voltage to the load despite fluctuations in supply voltage. This "following" action limits the heat disipation and protects the FET. Because the voltage regulator uses no inductors or transformers, there are no saturation problems and the circuit may be compactly packaged. No switching spikes are produced to cause video interference, and due to suppression of ripple current by the voltage regulator, there is little conducted electromagnetic interference (EMI).
37 Citations
13 Claims
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1. A voltage/current regulator for supplying regulated voltage from an unregulated source to a bridge and motor load and limiting an inrush current to the load comprising:
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a transistor connected in series with said load, said transistor including first and second current conducting electrodes and a control electrode; and control circuit means connected to said control electrode for controlling the conduction of said current conducting electrodes, said control circuit means including current limit feedback means for limiting the current drawn by said load, said control circuit means including bypass means to prevent said transistor from supplying bridge ripple current to said unregulated source. - View Dependent Claims (2, 13)
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3. A following voltage/current regulator for supplying regulated voltage from an unregulated source to a load and limiting an inrush current to the load comprising:
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a metal oxide semiconductor field effect transistor connected in series with said load, said field effect transistor including source, drain and gate electrodes; and control circuit means connected to said gate electrode for controlling the conduction of said field effect transistor, said control circuit means including first means for measuring the input voltage at said source electrode, second means for measuring the output voltage at said drain electrode, and third means for measuring the current drawn by said load, said control circuit means limiting inrush current to said load to a predetermined level until a predetermined voltage differential is achieved between said input and output voltages and thereafter automatically maintaining said predetermined voltage differential to provide for minimum losses in the field effect transistor. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification