Browse Prior Art Database

DC to DC Converter Using Autotransformer Technique

IP.com Disclosure Number: IPCOM000080896D
Original Publication Date: 1974-Mar-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Kinnard, JR: AUTHOR

Abstract

This converter utilizes a transformer in which the primary winding current flows into a portion of the secondary winding, which reduces the number of turns required in the primary winding and reduces the wire size ecessary for this portion of the secondary winding. A resultant savings in transformer size is achieved.

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DC to DC Converter Using Autotransformer Technique

This converter utilizes a transformer in which the primary winding current flows into a portion of the secondary winding, which reduces the number of turns required in the primary winding and reduces the wire size ecessary for this portion of the secondary winding. A resultant savings in transformer size is achieved.

Primary winding 10 of transformer 30 receives positive DC input voltage V1 at center-tap terminal 3. Assuming that transistor T1 is conducting, primary current I1 flows from terminal 3 through portion 1 of winding 10, through T1, through diode D1 and through load R1 to ground. Current 12, induced in portion 21 of secondary winding 20 of transformer 30, also flows through D1 and R1 to ground. The total load current, therefore, is I1 I2, which is supplied from both the primary and secondary windings of transformer 30.

Transistors T1 and T2 are alternately switched to provide a square-wave output from winding, 20 that is full-wave rectified by diodes D1 and D2 for portions 21 and 22 of winding 20, and by diodes D3 and D4 for portions 23 and 24 of winding 20 to provide DC output voltages to loads R1 and R2, respectively. Filtering of the output voltages is provided by capacitors C1 and C2.

Clock pulses 12 are applied to terminal 13 to cause T1 and T2 to change states. Pulses 12 toggle bistable multivibrator M1 and are common inputs to Nand's N1 and N2. The Q and Q outputs of M1 drive inputs of N1 and N2,...