Current driving circuit for inductive loads
US7439682B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 2007 |
| Grant date | Oct 21, 2008 |
| Priority date | — |
| Expiry date | Aug 23, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05G1/52
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A circuit for driving the current for inductive loads such as a electron beam deflection coil for an x-ray generator system. The circuit includes two selectable voltage levels which are provided by a high level voltage source and a low level voltage source or, alternatively, by a low level voltage source and a boosting converter. A plurality of switches for selecting the voltage source allow only one voltage source to be connected to the load at any given time, and for selecting the polarity of the current through the coil. The high level voltage source is selected when the load is charging or discharging. The low level voltage source is selected when the load is operating in a constant current mode, where a high frequency switching device uses the low level voltage source to generate a pulse width modulation waveform according to a reference current duty cycle to control the voltage across the load. A feedback loop monitors the current through the load so that the duty cycle of the pulse width modulation waveform may be adjusted to more accurately control the current through the load.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.