Browse Prior Art Database

Auto Ranging Power Supply

IP.com Disclosure Number: IPCOM000044046D
Original Publication Date: 1984-Oct-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Kugler, CJ: AUTHOR

Abstract

A technique is described whereby an automatic ranging concept is used to eliminate the need to rewire a system power supply in order to meet various line frequencies and voltage requirements of different countries and applications. Line frequencies of 50 and 60 Hz and line voltages between 100 and 300 volts are automatically adjusted to provide the proper voltages and line frequencies. In addition, the concept reduces power supply failure due to line voltage fluctuations. A small two-watt power supply circuit, as shown in Fig. 1, is used to provide 5 volts and 12 volts to the digital logic circuits, as shown in Fig. 2, which, in turn, selects the proper voltage connections for the main power supply. Triacs T1 to T18, as shown in Fig. 1, control the flow of current to the main power supply transformer X2.

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Auto Ranging Power Supply

A technique is described whereby an automatic ranging concept is used to eliminate the need to rewire a system power supply in order to meet various line frequencies and voltage requirements of different countries and applications. Line frequencies of 50 and 60 Hz and line voltages between 100 and 300 volts are automatically adjusted to provide the proper voltages and line frequencies.

In addition, the concept reduces power supply failure due to line voltage fluctuations. A small two-watt power supply circuit, as shown in Fig. 1, is used to provide 5 volts and 12 volts to the digital logic circuits, as shown in Fig. 2, which, in turn, selects the proper voltage connections for the main power supply. Triacs T1 to T18, as shown in Fig. 1, control the flow of current to the main power supply transformer X2. Bus bars 10, 11, and 12 provide the interconnections, hot, neutral and ground, respectively, to the primary of transformer X2. The secondary voltage of transformer X2, as shown in Fig. 2, is rectified by diode 13 and filtered by capacitor 14. A window detector circuit 15 determines if the input voltage is "in range." If the detector 15 determines that the range is above or below the specified voltage, the up/down counter 16 begins to count in the proper direction. Selector 17 selects the proper triacs T1 to T18 for the proper voltage to be applied to the primary of transformer X2, as shown in the typical triac gating circuit in Fig. 3. W...