Adaptive power direct current preregulator
AssigneeGeneral Instrument Corporation
InventorJeffrey S. Crompton
Life of this patent
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Abstract
A direct current (dc) overvoltage, pre-regulation circuit regulates dc voltage supplied to a cable television line amplifier. The circuit provides overvoltage protection while permitting continuous operation of the line amplifier. The circuit opens the input to the downstream continuous voltage regulation circuit and cyclically charges a filter storage capacitor by periodic applications of the un-clipped voltage. The repeated switching regulates the dc voltage such that operation is sustained during periods of overvoltage that would normally shut down conventional circuits. No overall feedback is required to control the active device.
Claims24
An open-loop adaptive overvoltage pre-regulator circuit comprising:
- a first switching means coupled directly in series with a first direct current leg of a full-wave rectifier and coupled directly in series with a terminal of a filter storage capacitor for electrically coupling said capacitor to said rectifier;
- means for activating said first switching means during normal voltage operating conditions;
- and
- means for deactivating said first switching means without feedback during overvoltage operating conditions.
An open-loop adaptive overvoltage pre-regulator for connection to the output of a direct current source comprising:
- a capacitor;
- switching means for controlling the charging of said capacitor;
- and
- monitoring means for monitoring voltage output from the direct current source wherein said switching means is responsive to said monitoring means without feedback.
A cable television line device comprising:
- means for receiving an input of a combined RF and Vac signal and outputting a Vac signal on a Vac output and a RF signal on a RF output;
- a full-wave rectifier having an ac input coupled to said Vac output and two direct current leg outputs;
- and
- an open-loop adaptive overvoltage pre-regulator circuit coupled to said direct current leg outputs including:
- a first switching means coupled directly in series with a first direct current leg output of said full-wave rectifier and coupled directly in series with a terminal of a filter storage capacitor for electrically coupling said capacitor to said rectifier;
- means for activating said first switching means during normal voltage operating conditions;
- and
- means for deactivating said first switching means without feedback during overvoltage operating conditions.
Dependencies are inferred from the claim text.