Browse Prior Art Database

Individual Regulation of Multioutput Power Supply by Tap Changing

IP.com Disclosure Number: IPCOM000087134D
Original Publication Date: 1976-Dec-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Hoffman, HS: AUTHOR

Abstract

Two versions of a power supply utilizing tap changing for fine regulation are described. In each case the number of cycles taken at each control condition determines the average output. The control can compensate for turns ratio problems as well as variations in load current.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 64% of the total text.

Page 1 of 2

Individual Regulation of Multioutput Power Supply by Tap Changing

Two versions of a power supply utilizing tap changing for fine regulation are described. In each case the number of cycles taken at each control condition determines the average output. The control can compensate for turns ratio problems as well as variations in load current.

Fig. 1 shows two individual flyback transformers L1 and L2, and Fig. 2 shows two pairs of regular T1 and T2 and flyback L3 and L4 transformers in series. In both cases, more outputs can be provided with additional hardware. This idea can also be adapted to other single-ended configurations.

With reference to Fig. 1, if Q2 and Q3, which handle only the difference power required for regulation, are not turned on, Q1 will switch two parallel primary flyback transformers L1 and L2. A snubbing, but not a clamping, circuit has been shown at 10. Q2 and Q3 do the tap changing for the two outputs. If during the ON time of Q1, Q2 is also on, the primary turns will be (m) rather than
(N). This changes the primary inductance, thereby giving a greater delta I for the same ON time and input voltage. By independent control of Q2 and Q3, the outputs can be individually controlled. Q1 regulates against input-voltage variation, while Q2 or Q3 provides control for individual load variations and compensation for turns-ratio problems with only the delta power capability. Diodes 12 and 14 prevent shorted turn problems on the windings. If the load c...