Power window switch which incorporates express up/down and window motor speed control features using a force sensitive resistor or capacitor
US5857061A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 28, 1997 |
| Grant date | Jan 5, 1999 |
| Priority date | — |
| Expiry date | Jan 28, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2300/01
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A system for enabling a vehicle operator to control the speed or rate of raising and lowering of a powered lift window. The actuator or switch includes a pressure responsive variable impedance device comprising a variable resistance in one embodiment and a variable capacitance in another embodiment. Increasing force directly on the variable impedance device by the user's finger or an actuator decreases the impedance which is sensed by a voltage divider which outputs a voltage which increases with increasing force. This latter voltage is compared with the output of a triangle wave oscillator and the output of the comparator is a pulse width modulated signal with pulse-width proportional to applied force. The pulses are applied to a power device (Mosfet) which modulates the duty cycle (%) of the current to the window lift mechanism drive motor to give variable motor speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.