Controlled ferroresonant transformer regulated power supply

• US 3,965,408 A
• Filed: 12/16/1974
• Issued: 06/22/1976
• Est. Priority Date: 12/16/1974
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Trubell, Lawrence Paul, Higuchi, Hobart Atsushi
• Primary Examiner(s): Pellinen, A. D.
• Application Number:
  US05/533,428
• Time in Patent Office: 554 Days
• Field of Search: 321/25, 323/6, 323/48, 323/56, 323/60, 323/61, 323/62, 323/89 C, 336/178, 336/184, 336/212, 336/215
• US Class Current: 363/75
• CPC Class Codes: G05F 1/38 semiconductor devices only
• CPC Class Codes: G05F 3/06 using combinations of saturated and unsaturated inductive devices, e.g. combined with resonant circuit
• CPC Class Codes: Y10S 174/17 in an electric power conversion, regulation, or protection system

Abstract

Standard configuration a.c. power transformer core sections are combined with standard configuration solenoid winding sections to provide a saturable core transformer which is arranged to be driven into saturation by applied alternating and direct current energy with the control of variations in flux changes up to saturation exercised by the direct current flow. A center tapped primary winding is arranged on an I-shaped stack of transformer iron laminations for full-wave excitation. A C-shaped stack of laminations is arranged adjacent to the I-shaped stack and separated by an air gap whereby the primary winding also serves as an input filter choke. The core structure is completed by an E-shaped stack of laminations arranged adjacent to the I-shaped stack and separated by another air gap. Two solenoid windings are arranged on the outer legs of the E-shaped stack and connected to a capacitor for resonating the overall ferroresonant transformer circuit arrangement. Secondary windings are also arranged on the outer legs and connected to a rectifying circuit for supplying direct potential to a load. A control winding is arranged on the central leg of the E-shaped stack of laminations. With this arrangement, the control winding is unaffected by variations in the a.c. voltage as they affect the flux changes in the transformer or in the frequency of the a.c. Regulation of the power supply is executed by direct current flow in the control winding. An adjustable resistor connecting the control winding across the output of the rectifier circuit is often all that is required to complete the circuit. In some applications, an amplifying circuit is used to provide a desired gain in the control winding circuitry.

Claims

1. A controlled ferroresonant transformer for a regulated power supply circuit arrangement comprising

a ferromagnetic electric transformer core comprising an E-shaped stack of laminations, and I-shaped stack of laminations and a C-shaped stack of laminations,

a primary winding arranged on said I-shaped stack with said C-shaped stack adjacent and spaced by an air gap for imparting the effect of a filter choke,

a secondary winding comprising two coils arranged on the outer legs of said E-shaped stack with the E-shaped stack adjacent said I-shaped stack and spaced by an air gap,

a resonating winding comprising two coils arranged on the outer legs of said E-shaped stack, and

a control winding arranged on the central leg of said E-shaped stack.

2. A controlled ferroresonant transformer assembly for a regulated power supply circuit arrangement comprising

a ferromagnetic electric transformer core comprising an E-shaped stack of laminations, an I-shaped stack of laminations and a C-shaped stack of laminations,

a primary winding arranged on said I-shaped stack with said C-shaped stack adjacent and spaced by an air gap for imparting the effect of a filter choke,

a secondary winding comprising two coils arranged on the outer legs of said E-shaped stack with the E-shaped stack adjacent said I-shaped stack with an air gap,

a resonating winding comprising two coils arranged on the outer legs of said E-shaped stack,

a capacitor connected across said resonating winding, and

a control winding arranged on the central lag of said E-shaped stack.

3. A controlled ferroresonant transformer as defined in claim 2 and wherein

said capacitor and said resonating winding have values of capacity and inductance at which the subcircuit thereby comprised is substantially resonant at the frequency of the alternating current for which the transformer is designed.

4. A controlled ferroresonant transformer regulated power supply circuit arrangement comprising

a ferromagnetic electric transformer core comprising an E-shaped stack of laminations, an I-shaped stack of laminations and a C-shaped stack of laminations,

a primary winding arranged on said I-shaped stack with said C-shaped stack adjacent and spaced by an air gap for imparting the effect of a filter choke,

a secondary winding comprising two coils arranged on the outer legs of said E-shaped stack with the E-shaped stack adjacent said I-shaped stack with air gap for stabilizing device gain,

a resonating winding comprising two coils arranged on the outer legs of said E-shaped stack,

a capacitor connected across said resonating winding,

a rectifier connected to said secondary winding,

a resistor connected to the output of said rectifier, and

a control winding arranged on the central leg of said E-shaped stack and connected in series with said resistor and said rectifier.

5. A controlled ferroresonant transformer regulated power supply circuit arrangement as defined in claim 4 and incorporating

isolating diodes interposed at the terminals of said primary winding.

6. A controlled ferroresonant transformer regulated power supply circuit arrangement as defined in claim 4 and wherein

a reference potential and actuating signal generating circuit is connected between said control winding and said resistor and arranged for adjusting current flow in said control winding.

7. A controlled ferroresonant transformer regulated power supply circuit arrangement as defined in claim 6 and wherein

said reference potential and actuating signal generating circuit is adjustable.

8. A controlled ferroresonant transformer regulated power supply circuit arrangement as defined in claim 4 and incorporating

a variable resistance device having a control terminal and having a resistance element interposed in series with said resistor, said control winding and said rectifier,

a differential amplifying circuit having an output terminal coupled to said control terminal and two input terminals,

electric circuitry connected across said rectifier for deriving an input signal reflecting any variation in potential and connected to one of said input terminals of said amplifying circuit,

an electric circuit arranged for generating a reference input level substantially free from said variation and connected to the other input terminal of said amplifying circuit,

other secondary winding sections arranged on the outer legs of said E-shaped core stack, and

another rectifier circuit connected between said other secondary winding sections and said amplifying circuit for energizing the latter circuit.

9. A controlled ferroresonant transformer regulated power supply circuit arrangement as defined in claim 8 and incorporating

a potentiometer connected in the reference input level generating circuit of said interconnected amplifying circuit and said rectifying circuit and having a tapping connected to the other input terminal of said amplifying circuit.

10. A controlled ferroresonant transformer regulated power supply circuit arrangement as defined in claim 8 and wherein

said variable resistance device comprises a current controlling transistor connected to said amplifying circuit and having the collector-emitter electrode circuit connected in series with said control winding and said rectifier circuit independently of said connections for energizing said amplifying circuit.

11. A controlled ferroresonant transformer regulated power supply circuit arrangement comprising

a ferromagnetic electric transformer core comprising an E-shaped stack of laminations, an I-shaped stack of laminations and a C-shaped stack of laminations,

a primary winding arranged on said I-shaped stack with said C-shaped stack adjacent and spaced by an air gap for imparting the effect of a filter choke,

a secondary winding comprising two coils arranged on the outer legs of said E-shaped stack with the E-shaped stack adjacent said I-shaped stack with air gap for stabilizing device gain,

a resonating winding comprising two coils arranged on the outer legs of said E-shaped stack,

a capacitor connected across said resonating winding,

said capacitor and said resonating winding have values of capacity and inductance at which the subcircuit thereby comprised is substantially resonant at the frequency of the alternating current for which the transformer is designed,

a control winding arranged on the central leg of said E-shaped stack,

a rectifier connected to said secondary winding,

electric leads for connecting an electric load device to said rectifier,

a differential amplifying circuit having two input terminals and an output terminal,

other secondary winding sections arranged on the outer legs of said E-shaped core stack, and

another rectifier circuit connected between said other secondary winding sections and said amplifying circuit for energizing the latter circuit,

a current controlling transistor having a base electrode connected to said output terminal of said amplifying circuit and having the collector-emitter electrode circuit connected in series with said control winding and said other rectifier circuit,

a potentiometer connected in the direct current energizing circuit of said interconnected amplifying circuit and said other rectifying circuit and having a tapping connected to one of the input terminals of said amplifying circuit, and

a voltage divider connected between said electric leads for detecting any variation in potential at said electric leads and having a tapping connected to the other input terminal of said amplifying circuit.