Power supply circuit of an excitation coil of an electromagnet
US5805405A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 1996 |
| Grant date | Sep 8, 1998 |
| Priority date | — |
| Expiry date | Oct 10, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F2029/143
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A power supply circuit, using direct current or rectified alternating current sources having output and return supply lines (a, b), for a coil of an electromagnet having at least one principal winding (B1) and a secondary winding (B2). The power supply circuit includes a first semiconductor element (T2) having a gate and a source drain path and capable of providing or blocking a supply of current to the secondary winding (B2), the source drain path connected between the secondary winding (B2) and the return supply line (b); and a switching means (10) connected between the primary winding (B1) and the gate of the first semiconductor element (T2). The switching means (10) includes a second semiconductor element (T1) having a gate and a source drain path and capable of keeping the first semiconductor element (T2) from conducting when a voltage between the gate of the second semiconductor element (T1) and the return supply line (b) reaches a threshold voltage (Vs) greater than a value (V1) corresponding to a start of a closing of the electromagnet, the source drain path of the second semiconductor element (T1) connected between the gate of the first semiconductor element (T2) and the r…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.