Switching circuit controlling multiple heating elements

• US 20070102422A1
• Filed: 10/31/2006
• Published: 05/10/2007
• Est. Priority Date: 11/04/2005
• Status: Active Grant

• Current Assignee: Siemens PLC (Siemens AG)
• Original Assignee: Siemens Magnet Technology Limited (Siemens AG)
• Inventors: Thomas, Adrian
• Granted Patent: US 7,868,275 B2
• Time in Patent Office: Days
• US Class Current: 219/666
• CPC Class Codes: G01R 33/3815 with superconducting coils, e.g. power supply therefor
• CPC Class Codes: H01F 6/003 Methods and means for discharging superconductive storage superconducting alloys C22C; static memories with superconducting elements G11C11/44; superconducting circuit breakers with contacts H01H33/004; superconducting switches for low power H03K17/92; superconducting material H10N60/00; power cryotons H10N60/355
• CPC Class Codes: H01F 6/005 Methods and means for increasing the stored energy in superconductive coils by increments (flux pumps)
• CPC Class Codes: H01F 6/02 Quenching; Protection arrangements during quenching protection circuits H02H7/001

Abstract

A switching circuit comprising a plurality of heating elements (12), each connected as part of a tuned circuit (36), the tuned circuits being respectively tuned to different frequencies and connected in parallel between two common conductors (34), the circuit further comprising means (20, 38, 40) for applying an oscillating signal voltage between the two common conductors, at one or more frequencies each corresponding to a tuned frequency of one of the tuned circuits.

Claims

1. A switching circuit comprising a plurality of heating elements, each connected as part of a tuned circuit, the tuned circuits being respectively tuned to different frequencies and connected in parallel between two common conductors, the circuit further comprising means for applying an oscillating signal voltage between the two common conductors, at one or more frequencies each corresponding to a tuned frequency of one of the tuned circuits.

2. A switching circuit according to claim 1 wherein each tuned circuit comprises a resistive heating element in series with a capacitor and an inductor.

3. A switching circuit according to claim 1 wherein each tuned circuit comprises a resistive, inductive heating element in the form of an inductive coil of resistive wire, connected in series with a capacitor.

4. A switching circuit according to claim 1, wherein the means for applying an oscillating voltage comprises a control system arranged to control a frequency generator to generate a signal at the one or more frequencies.

5. A switching circuit according to claim 4, wherein the means for applying an oscillating voltage further comprises an amplifier arranged to receive the signal at one or more frequencies from the frequency generator, to amplify said signal and to apply such amplified signal between the common conductors.

6. A cryostat housing superconducting components, and a number of heaters, at least some of said heaters being each thermally linked to a corresponding part of a superconducting component, said heaters forming part of a switching circuit according to claim 1, wherein the tuned circuits are located within the cryostat, while the means for applying a signal voltage are placed outside of the cryostat.

7. A cryostat according to claim 6 wherein one of the common conductors is composed of a body of the cryostat.

8. (canceled)