Browse Prior Art Database

Limit Cycle Voltage Regulator

IP.com Disclosure Number: IPCOM000089144D
Original Publication Date: 1977-Sep-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 3 page(s) / 42K

Publishing Venue

IBM

Related People

Driscoll, CD: AUTHOR

Abstract

A limit cycle regulator for the voltage of a power supply is a DC-to-DC regulator in which a supply voltage higher than the load voltage is connected to the load through an L-C filter 7 so long as the load voltage is below an upper limit. It is disconnected when the load voltage reaches the upper limit, and is reconnected when the load voltage drops to a lower limit. This type of supply provides excellent regulation for varying loads, has a fixed ripple voltage, and needs no adjustable components.

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Limit Cycle Voltage Regulator

A limit cycle regulator for the voltage of a power supply is a DC-to-DC regulator in which a supply voltage higher than the load voltage is connected to the load through an L-C filter 7 so long as the load voltage is below an upper limit. It is disconnected when the load voltage reaches the upper limit, and is reconnected when the load voltage drops to a lower limit. This type of supply provides excellent regulation for varying loads, has a fixed ripple voltage, and needs no adjustable components.

As shown above, DC power at a relatively high voltage is supplied on V(IN) input line 1 to a power switching circuit 2. Circuit 2 comprises a power transistor 3, in series between input 1 and the L-C filter 7, and a base control transistor 5 having its base voltage controlled by a drive line 6 to turn transistor 3 on and off.

The L-C filter circuit 7 includes a load capacitor to be charged by transistor 3 when conducting, and a snubber circuit to reduce the peak power dissipation in transistor 3 during switching.

The base of control transistor 5 is activated by a drive circuit 8 which is controlled by an AND 3 receiving inputs from a control circuit 10 and a voltage control latch 11. Circuit 10 will be set and reset by a start/stop line 12 to turn power on and off and can be reset by a remotely controlled line 13. An overcurrent sensing device 14 on V(OUT) line 4 will also energize line 13 on an overload condition. An over-voltage protector 15 also on V(OUT) line 4 will react to put a short circuit on line 4 if an over-voltage condition occurs.

The voltage on line 4 is controlled by turning the drive circuit 8 on or off by resetting and setting latch 11. The latch will be reset when the input voltage to filter 7, through voltage divider 16, is determined by comparator 17 to be at or below the voltage on a lower l...