High frequency control circuit for DC motors, particularly for washing machines
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Nov 19, 1996
Grant Date -
N/A
app pub date -
Jan 24, 1995
filing date -
Jan 25, 1994
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A control circuit for a series type dc motor. The control circuit uses a switching cell to control motor speed. The switching cell and motor receive power from a filtered dc supply. A tachometer generator produces a voltage proportional to motor speed. The speed voltage is compared to a speed reference signal voltage and the difference is proportionally integrated to develop a speed error signal voltage. The speed reference signal voltage is developed at a summing node where a current generated by the control's microcontroller is summed with a current proportional to the input ripple voltage of the control's dc supply. The microcontroller also receives a voltage proportional to the control's dc input as a reference. The speed error signal voltage is compared with the output voltage of a current sensor that is in series with the motor feeder arrangement and the comparator's output is used to reset a bistable flip flop. The flip flop controls the switching cell and is set by a high frequency oscillator (100-150 khz). The cell closes when the flip flop is set and opens when the cell is reset. This control determines power absorbed by the motor and improves the motor power factor.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Advertisement
Advertisement
Advertisement
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully