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PHASE CONTROLLED REGULATED POWER SUPPLY

IP.com Disclosure Number: IPCOM000024780D
Original Publication Date: 1982-Feb-28
Included in the Prior Art Database: 2004-Apr-03
Document File: 4 page(s) / 182K

Publishing Venue

Xerox Disclosure Journal

Abstract

Referring to Figure 1, there is shown a phase controlled, regulated power supply which is relatively insensitive to rapid power fluctuations occurring in an AC line source. As shown, a 115v 60Hz line voltage is applied to conventional DC bridge rectifier 20 which includes four diodes 20a, 20b, 20c and 20d, connected as shown. Rectifier 20 converts the applied AC power to full wave rectified DC power across the output leads 22, 24. The output on lead 22 has a 12Ocps ripple component which is filtered by a circuit comprising capacitor 26, zener diode 27 and resistor 28. This filtered DC voltage is then used to provide power along lead 25 to the amplifier circuits and a biasing signal to circuit 60, as will be seen.

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Page 1 of 4

XEROX DISCLOSURE JOURNAL

PHASE CONTROLLED REGULATED Proposed Classification POWER SUPPLY U.S. C1. 323/237 Randolph A. Bullock
Int. Lawrence J. Mason C1. G05f 1/10

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Referring to Figure 1, there is shown a phase controlled, regulated power supply which is relatively insensitive to rapid power fluctuations occurring in an AC line source. As shown, a 115v 60Hz line voltage is applied to conventional DC bridge rectifier 20 which includes four diodes 20a, 20b, 20c and 20d, connected as shown. Rectifier 20 converts the applied AC power to full wave rectified DC power across the output leads 22, 24. The output on lead 22 has a 12Ocps ripple component which is filtered by a circuit comprising capacitor 26, zener diode 27 and resistor
28. This filtered DC voltage is then used to provide power along lead 25 to the amplifier circuits and a biasing signal to circuit 60, as will be seen.

The full wave, rectified DC output on lead 22 is applied to a lOOW, lOOV tungsten lamp 30 in series with transistor switch 40 consisting of Darlington transistor 42

Volume 7 Number 1 January/February 1982 19

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Page 2 of 4

PHASES CONTROLLED REGULATED POWER SUPPLY (Contsd)

FIG 2

FULL WAVE RECTIFIED D.C. SIGNALS

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and resistors 44, 45. Transistor 43 provides an overcurrent shutdown of the output to protect transistor pair 42 during warmup of the lamp. Photosensor circuit 50
which monitors the light output of lamp 30 includes a photodiode 52 and operational amplifier 54. Photodiode 52 generates an output current proportional to the irradiance from lamp 30 impinging thereon. Capacitor 56 filters out any ripple components. Amplifier 54 provides a current-to-voltage conversion of the photodiode signal and its output signal VL is proportional to the input photodiode signal and the gain of the circuit (controlled by potentiometer 58).

Voltage signal V is applied to the positive input of operational amplifier 61 in amplifier-cornparktor circuit 60. The rectified, filtered output from lead 22 is applied to the negative input of amplifier 61 across a voltage divide comprising resistors 62, 63. Amplifier 61 output signal, Vc, is proportional to the input signal from amplifier 54 and the gain of the circuit as set by resistor 64. For the selected component values, amplifier 61 provides a non-inverted voltage output with a gain of approximately 10.

The voltage output, V , of amplifier 61, is applied to the negative input of operational amplifier 6?across resistor 66. This input is compared with a fraction of the rectified line voltage on lead 22, applied to amplifier 65 across a voltage divider consisting of resistors 67, 68. The output V of amplifier 65 is therefore proportional to the input signal from amplifier 61 an8the gain as set by resistor 69. For the indicated component values, amplifier 65 provides a non-...