US 7,839,109 · Granted 2010-11-23
How Smart Blinds Keep Running When Power Dips
This patent protects a clever trick that keeps motorized blinds and shades moving smoothly even when your home's electrical power is weak or unstable. Instead of grinding to a halt or breaking, the motor automatically throttles back just enough to let power recover, then picks up right where it left off.
The plain-English version
What it protects
The claim covers a method for controlling a motorized window treatment (like motorized blinds or shades) that monitors the electrical power feeding the motor. When power dips below a safe threshold, the controller automatically reduces the motor's speed or pauses it briefly instead of shutting down completely. Once power stabilizes, it resumes normal operation. The core protection is this real-time voltage-sensing and adaptive motor control strategy that prevents total failure during brownouts or electrical strain.
Why it matters
Motorized window treatments are luxury features in homes and offices, and they need to work reliably even on older electrical circuits or during demand spikes. This patent solves a real durability problem: a standard motor would simply stall and fail, frustrating users and requiring service calls. By keeping the system smart and adaptive, Lutron Electronics (a major player in smart home control) protects both the reliability of their products and their market position in premium home automation.
Real-world use
When you command your motorized blinds to close at sunset and your home's electrical load spikes because the air conditioner just kicked on, the blinds keep closing smoothly rather than jerking to a stop halfway.
Original USPTO abstract
A method of controlling a motorized window treatment provides for continued operation of the motorized window treatment during an overload or low-line condition. The motorized window treatment is driven by an electronic drive unit having a motor, a motor drive circuit, and a controller. The controller controls the motor drive circuit to drive the motor with a pulse-width modulated signal generated from a bus voltage. The controller is operable to monitor the magnitude of the bus voltage. If the bus voltage drops below a first voltage threshold, the controller stops the motor or reduces the duty cycle of the pulse-width modulated signal to allow the bus voltage to increase to an acceptable magnitude. When the bus voltage rises above a second voltage threshold, the controller begins driving the motor normally once again. During an overload or low-line condition, the controller is prevented from resetting, while driving the motor with minimal interruption to the movement of the motorized window treatment.
Patent details
- Publication number
- US 7,839,109
- Filing date
- 2008-04-04
- Grant date
- 2010-11-23
- Assignee
- Lutron Electronics Co., Inc.
- Inventor(s)
- CARMEN, JR. LAWRENCE R., BRENNER THOMAS WARREN, LUNDY STEPHEN
- CPC class
- H02P7/29
Want to file your own patent?
If you're designing a home-improvement gadget that runs on electricity, check IsItPatented.ai to see what voltage-control methods are already locked down before you engineer your own.
Free patentability scan