# US 7,411,356 B2 · Power supply for multiple discharge lamps and the current balance device thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,411,356 B2 - Document ID: US7411356B2 - Status: Granted - Kind: B2 - Application number: 11/537,300 - Filed: 2006-09-29 - Published: 2007-10-18 - Granted: 2008-08-12 - Earliest claimed: 2006-04-17 - Assignees: Delta Electronics, Inc. - Inventors: Zengyi Lu; Wei Chen; Dengyan Zhou - Web page: https://patentgrep.com/patent/US7411356B2 ## CPC - H05B 41/282: with semiconductor devices ({H05B41/2806}, H05B41/288, H05B41/295 take precedence) - Y02B 20/00: Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A power supply for discharge lamp includes a transformer and a current balance device, wherein the transformer includes a primary winding and a secondary winding and the current balance device is coupled between the secondary winding and a plurality of discharge lamps. The current balance device may include a single inductor wherein at least two windings are connected in series with each other and each serially-connected winding is coupled with a discharge lamp, and the other windings are respectively coupled with a discharge lamp. The current balance device may include two inductors wherein at least one winding of a first inductor is connected in series with at least one winding of a second inductor and each serially-connected winding is coupled with a discharge lamp, and the other windings of the first inductor and the other windings of the second inductor are respectively coupled with a discharge lamp. ## Claims ### Claim 1 A power supply for multiple discharge lamps, comprising: a transformer; and a current balance device coupled between the transformer and a plurality of discharge lamps, wherein the current balance device comprises an inductor having a magnetic core with a plurality of legs and a plurality of windings and each leg has one winding wound thereon, wherein at least two of the plurality of windings are connected in series with each other and each serially-connected winding is coupled to a discharge lamp, and the other windings are respectively coupled to a discharge lamp. ### Claim 2 (depends on 1) The power supply for multiple discharge lamps according to claim 1 wherein the discharge lamp is a cold cathode fluorescent lamp. ### Claim 3 (depends on 1) The power supply for multiple discharge lamps according to claim 1 wherein an initial winding and an end winding of the plurality of windings are respectively connected with an intermediate winding. ### Claim 4 (depends on 1) The power supply for multiple discharge lamps according to claim 1 wherein each of the plurality of windings has the same turn number. ### Claim 5 (depends on 1) The power supply for multiple discharge lamps according to claim 1 wherein the transformer has a primary winding and a secondary winding and configured to receive an input voltage through the primary winding and induce an output voltage across the secondary winding. ### Claim 6 (depends on 1) The power supply for multiple discharge lamps according to claim 1 wherein the number of the legs within the inductor is larger than three. ### Claim 7 A power supply for multiple discharge lamps, comprising: a transformer; and a current balance device coupled between the transformer and a plurality of discharge lamps, wherein the current balance device comprises: a first inductor having a magnetic core with a plurality of legs and a plurality of windings and each leg having one winding wound thereon; and a second inductor having a magnetic core with a plurality of legs and a plurality of windings and each leg having one winding wound thereon; wherein at least one winding of the first inductor and at least one winding of the second inductor are connected in series with each other and each serially-connected winding is coupled to a discharge lamp, and the other windings of the first inductor and the other windings of the second inductor are respectively coupled to a discharge lamp. ### Claim 8 (depends on 7) The power supply for multiple discharge lamps according to claim 7 wherein the discharge lamp is a cold cathode fluorescent lamp. ### Claim 9 (depends on 7) The power supply for multiple discharge lamps according to claim 7 wherein each winding of the first inductor has the same turn number, and each winding of the second inductor has the same turn number. ### Claim 10 (depends on 7) The power supply for multiple discharge lamps according to claim 7 wherein the transformer has a primary winding and a secondary winding and configured to receive an input voltage through the primary winding and induce an output voltage across the secondary winding. ### Claim 11 (depends on 7) The power supply for multiple discharge lamps according to claim 7 wherein the number of the legs within each inductor is larger than three. ### Claim 12 A power supply for multiple discharge lamps including: a transformer; and a current balance device coupled between the transformer and a plurality of discharge lamps, wherein the current balance device comprises: a plurality of inductors, each of which has a magnetic core with a plurality of legs and a plurality of windings and each leg has one winding wound thereon; wherein a portion of windings allocated to different inductors are connected in series with each other and each serially-connected winding is coupled to a discharge lamp, and the other windings of the plurality of inductors are respectively coupled to a discharge lamp. ### Claim 13 (depends on 12) The power supply for multiple discharge lamps according to claim 12 wherein the number of inductors is equal to or larger than three. ### Claim 14 (depends on 12) The power supply for multiple discharge lamps according to claim 12 wherein each winding of the same inductor has the same turn number. ### Claim 15 (depends on 12) The power supply for multiple discharge lamps according to claim 12 wherein the transformer has a primary winding and a secondary winding and configured to receive an input voltage through the primary winding and induce an output voltage across the secondary winding. ### Claim 16 (depends on 12) The power supply for multiple discharge lamps according to claim 12 wherein the number of the legs within each inductor is larger than three.