Highway crossing guard mechanism controller
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
May 5, 1998
Grant Date -
N/A
app pub date -
Jan 30, 1997
filing date -
Jan 30, 1997
priority date (Note) -
Expired
status (Latency Note)
Importance
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Abstract
A highway crossing gate control circuit is provided which minimizes the 'pumping' oscillation of a highway crossing gate arm which is driven up by a permanent magnet motor. A preferred embodiment of the control circuit utilizes a p-channel MOSFET in a power down module of the control circuit to restrict power from being applied to the motor when the gate arm is in an up position and is intended to be held in the up position by a hold clear device which acts as a mechanical break. Provision is included for dynamic braking on the gate arm moving downward after an initial drive down mode.
First Claim
Other Claims data not available