Browse Prior Art Database

Automatic Input Voltage Regulator

IP.com Disclosure Number: IPCOM000038861D
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 45K

Publishing Venue

IBM

Related People

Celenza, N: AUTHOR

Abstract

The article provides a circuit arrangement which senses the output of a voltage halving converter. It disables the halving function if the output is below a predetermined voltage level and enables the halving function if the output is above a predetermined voltage level. The circuit shown to the left of the dashed lines in the figure accepts an AC signal at terminals ACH and ACN, rectifies the signal with components CR1, CR2, CR3 and CR4 and outputs a signal at terminals Vb+ to Vb- equivalent to one-half the peaked rectified voltage. The halving circuit is functionally similar to the halving circuit disclosed in the IBM Technical DisclosureBulletin 24, 1178-1181 (July 1981). The circuit enclosed in the broken lines senses the state of the voltage (between terminals Vb+ and Vb-).

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Automatic Input Voltage Regulator

The article provides a circuit arrangement which senses the output of a voltage halving converter. It disables the halving function if the output is below a predetermined voltage level and enables the halving function if the output is above a predetermined voltage level. The circuit shown to the left of the dashed lines in the figure accepts an AC signal at terminals ACH and ACN, rectifies the signal with components CR1, CR2, CR3 and CR4 and outputs a signal at terminals Vb+ to Vb- equivalent to one-half the peaked rectified voltage. The halving circuit is functionally similar to the halving circuit disclosed in the IBM Technical DisclosureBulletin 24, 1178-1181 (July 1981). The circuit enclosed in the broken lines senses the state of the voltage (between terminals Vb+ and Vb- ). If the voltage is above a predetermined threshold (high), zener diode CR2' senses the high voltage and it turns Q2' on. With Q2' on, Q1' is off and the voltage outputted at Vb+ to Vb- is one-half of the rectified voltage. When Vb drops below a predetermined value (low), zener diode CR2' senses the low voltage and stops conducting. This, in turn, turns Q2' off and renders Q1' conductive. With Q1' conducting, Q1 is turned off and the voltage at Vb is not halved. Thus, when the output voltage Vb is low (say, 110 V), the circuit enclosed with the broken lines prevents Q1 from conducting, and, as a result, the voltage which is rectified is not halved. Alterna...