**Exhibit 21**

**Power-One, Inc.—Listof Subsidiaries**

| **NAMED ENTITY**                                                                                                                                      | ** ** | ** **     | ** ** | **JURISDICTION/COUNTRY** |
|-------------------------------------------------------------------------------------------------------------------------------------------------------|------------|----------------|------------|--------------------------|
| ·Power-One  Energy Solutions Pty Ltd.                                                                                                            |       | Australia      |
| ·Power-One  BVBA                                                                                                                                 |       | Belgium        |
| ·Power-One  Limited                                                                                                                              |       | Cayman Islands |
| ·Power-One  Co. Ltd.                                                                                                                             |       | China          |
| ·Magnetek  Electronics (Shenzhen) Co. Ltd. (pending name change to Power-One Asia  Pacific Electronics (Shenzhen) Co. Ltd.)                      |       | China          |
| ·Power-One  I/S                                                                                                                                  |       | Denmark        |
| ·Power-One  Denmark ApS                                                                                                                          |       | Denmark        |
| ·Power-One  OY                                                                                                                                   |       | Finland        |
| ·Power-One  S.A.                                                                                                                                 |       | France         |
| ·Power-One  GmbH                                                                                                                                 |       | Germany        |
| ·Power-One  Germany Holdings GmbH                                                                                                                |       | Germany        |
| ·Power-One  Limited                                                                                                                              |       | Great Britain  |
| ·Power-One  Ltd.                                                                                                                                 |       | Hong Kong      |
| ·Magnetek  Kft (pending name change to Power-One Hungary Holdings Electronic Equipment  Manufacturing and Trading Limited Liability Company Kft) |       | Hungary        |
| ·Power-One  Ireland Ltd.                                                                                                                         |       | Ireland        |
| ·Power-One  Italy Holdings S.p.A.                                                                                                                |       | Italy          |
| ·Power-One  Italy S.p.A.                                                                                                                         |       | Italy          |
| ·Power-One  Energy Solutions SDN BHD                                                                                                             |       | Malaysia       |
| ·Power-One  B.V.                                                                                                                                 |       | Netherlands    |
| ·Power-One  Norge AS                                                                                                                             |       | Norway         |
| ·Power-One  AS                                                                                                                                   |       | Norway         |
| ·Power-One  Limited Liability Company                                                                                                            |       | Russia         |
| ·Power-One  Pte. Ltd.                                                                                                                            |       | Singapore      |
| ·Power-One  s.r.o.                                                                                                                               |       | Slovakia       |
| ·Power-One  Power Solutions AB                                                                                                                   |       | Sweden         |
| ·Power-One  AG                                                                                                                                   |       | Switzerland    |
| ·Melcher  Holding, Inc.                                                                                                                     |       | USA            |
| ·Melcher, Inc.                                                                                                                              |       | USA            |
| ·HC  Power, Inc.                                                                                                                            |       | USA            |
| ·P-O  Delaware Corp.                                                                                                                             |       | USA            |
| ·P-O  Nevada Corp.                                                                                                                               |       | USA            |
| ·PAI Capital LLC                                                                                                                                 |       | USA            |

 

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