PWM controller for DC powered heating blanket
US6770853B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 2002 |
| Grant date | Aug 3, 2004 |
| Priority date | — |
| Expiry date | Dec 23, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S2/905
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A PWM-based controller for controlling a voltage applied to a DC-powered electric heating blanket from a power source includes a square wave producing circuit for connection in the circuit with the battery and the blanket. The square wave producing circuit produces a variable duty cycle square wave for controlling application of power to the blanket in accordance with the duty cycle of the square wave. The square wave producing circuit has a control input for varying the duty cycle of the square wave in response to a voltage at the control input. The voltage at the control input may be set manually using a voltage varying circuit connected to the power source. A low voltage detection circuit may also be connected to the power source and coupled to the control input of the square wave producing circuit for automatically producing a voltage that decreases the duty cycle of the square wave when the battery voltage decreases to or below a predetermined level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.