| Ferroresonant |
| Ametek Solidstate Controls | http://www.solidstatecontrolsinc.com |
| Ferroresonant |
| Neeltran | http://www.neeltran.com |
| Velocity | Air | Belimo Aircontrols (USA), Inc. | http://www.belimo.com/ |
| Voltage |
| Ametek Solidstate Controls | http://www.solidstatecontrolsinc.com |
| Voltage |
| Diversified Electronics | http://www.atcdiversified.com |
| Voltage |
| Eaton Electrical Inc. | http://www.eatonelectrical.com |
| Voltage |
| GE Electrical Distribution & Control | http://www.geindustrial.com |
| Voltage |
| Neeltran | http://www.neeltran.com |
| Voltage |
| Staco Energy Products Co | http://www.StacoEnergy.com |
| Voltage |
| Superior Electric | http://www.superiorelectric.com |