EP0168183A1
Expired / Lapsed
EP
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Power transfer circuit
Assignee: Sharp Corp
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Filing: 1985-06-14
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Granted: —
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Expires: 2005-06-14
Abstract
Abstract A power transfer circuit includes a power transformer (2) having a center tap (12) provided in its secondary winding, a full-wave rectifier circuit (13), a level discriminator circuit (15) and a switching circuit (14). In response to a level discrimination made by the level discriminator circuit that a DC voltage outputted from one output terminal of the full-wave rectifier circuit is less than a predetermined voltage level, a transistor (Q1) and a thyristor (SCR) of the switching circuit are made conductive so as to ground the other output terminal of the full-wave rectifier circuit. In response to a level discrimination made by the level discriminator circuit that the DC voltage outputted from the said one output terminal of the full-wave rectifier circuit exceeds the predetermined voltage level, a diode (D9) connected to the center tap of the power transformer is made conductive to ground the center tap. Thus, the full-wave rectifier circuit outputs a constant DC voltage even if AC voltages at different levels are inputted in primary winding of the power transformer.
Inventors
- 👤 Hiroshi Terada
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 03:48
CPC Classifications
H; H02; H02M; H02M1/00; H02M1/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
114 words
A power transfer circuit comprising: a power transformer (2) provided with secondary winding having a center tap (3); a full-wave rectifier circuit (8) connected to both ends of said secondary winding of said power transformer to form a bridge circuit, thereby to rectify AC voltages generated on both ends of said secondary winding and output a DC voltage; and switching control means (D9, SCR, 14, 15) respectively connected between said center tap of said secondary winding of said power transformer and the ground and between one output terminal of said full-wave rectifier circuit and the ground, thereby to selectively ground either said center tap or said one output terminal of said full-wave rectifier circuit.
Claim 2
Dependent Claim
114 words
A power transfer circuit comprising: a power transformer (2) provided with secondary winding having a center tap (3); a full-wave rectifier circuit (8) connected to both ends of said secondary winding of said power transformer to form a bridge circuit, thereby to rectify AC voltages generated on both ends of said secondary winding and output a DC voltage; and switching control means (D9, SCR, 14, 15) respectively connected between said center tap of said secondary winding of said power transformer and the ground and between one output terminal of said full-wave rectifier circuit and the ground, thereby to selectively ground either said center tap or said one output terminal of said full-wave rectifier circuit.
Claim 3
Dependent Claim
172 words
A power transfer circuit in accordance with claim 1, wherein said switching control means include: level discriminator means (15) for making level discrimination as to whether or not a DC voltage outputted from said output terminal of said full-wave rectifier circuit exceeds a predetermined level, switching elements (D9, SCR) connected between said center tap of said secondary winding of said power transformer and the ground and between the other output terminal of said full-wave rectifier and the ground, and switching control means (14) for controlling said switching elements so as to ground said other terminal of said full-wave rectifier circuit in response to a level discrimination made by said level discriminator means that said DC voltage outputted from said one output terminal of said full-wave rectifier circuit is less than said predetermined level and to ground said center tap of said secondary winding of said power transformer in response to a level discrimination that said DC voltage outputted from said one output terminal of said full-wave rectifier circuit exceeds said predetermined level.
Claim 4
Dependent Claim
74 words
A power transfer circuit in accordance with claim 2, wherein said level discriminator means includes: a first Zener diode (ZD2) having a cathode connected to said one output terminal of said full-wave rectifier circuit and a grounded anode, and a second Zener diode (ZD1) having a cathode connected to said one output terminal of said full-wave rectifier circuit and an anode connected to said center tap of said secondary winding of said power transformer.
Claim 5
Dependent Claim
67 words
A power transfer circuit in accordance with claim 2, wherein said switching elements include: a diode (D9) connected between said center tap of said secondary winding of said power transformer and the ground, and a thyristor (SCR) having a control electrode connected to an output of said switching control means, a cathode connected to said other output terminal of said full-wave rectifier circuit and a grounded anode.
Claim 6
Dependent Claim
84 words
A power transfer circuit in accordance with claim 2, wherein said switching control means include: a first transistor (Q2) having an emitter connected to said one output terminal of said full-wave rectifier circuit and a base connected to a level discrimination output of said level discriminator means, and a second transistor (Ql) having an emitter connected to said one output terminal of said full-wave rectifier circuit, a base connected to the collector of said first transistor and a collector connected to said switching element.
Claim 7
Dependent Claim
209 words
A power transfer circuit comprising: a winding having a centre tap; a bridge rectifying circuit the power input terminals of which are electricall connected to the winding and a first power output terminal of which is connected for power output to a load; and a switch means which in a first position causes the bridge rectifying circuit to provide at the said first power output terminal a rectified voltage obtained from the alternating voltage across the full length of the winding and in a second position causes the bridge rectifying circuit to provide at the said first power output terminal a rectified voltage obtained from the alternating voltage across half the length of the winding by use of the centre tap, characterised in that the winding is the secondary winding of a transformer, the power input terminals of the bridge rectifying circuit are connected across the full length of the winding, and the switch means is connected to the centre tap and to the second power output terminal of the bridge rectifier circuit and in its first position connects the said second power output terminal to a potential common to the load and in its second position connects the said centre tap to the potential common to the load.
Claim 8
Dependent Claim
209 words
A power transfer circuit comprising: a winding having a centre tap; a bridge rectifying circuit the power input terminals of which are electricall connected to the winding and a first power output terminal of which is connected for power output to a load; and a switch means which in a first position causes the bridge rectifying circuit to provide at the said first power output terminal a rectified voltage obtained from the alternating voltage across the full length of the winding and in a second position causes the bridge rectifying circuit to provide at the said first power output terminal a rectified voltage obtained from the alternating voltage across half the length of the winding by use of the centre tap, characterised in that the winding is the secondary winding of a transformer, the power input terminals of the bridge rectifying circuit are connected across the full length of the winding, and the switch means is connected to the centre tap and to the second power output terminal of the bridge rectifier circuit and in its first position connects the said second power output terminal to a potential common to the load and in its second position connects the said centre tap to the potential common to the load.
References Cited (Backward Citations)
US2777107A
Cited
DE2007959A1
Cited
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