Thanks, Tom! That all makes sense! Come to think of it, the Briggs & Stratton engine on my 5500 watt generator maintains its speed well. I don't know what sort of feedback it uses, but it's effective! If I make a big load change, like bringing on a water heater, I can hear a "pitch" change but the speed remains constant. In the old days I've seen trucks and tractors used to run saws for cutting timber. I guess that sort of give awa y how old I am and what a "hillbilly" I am! :-)
Take care down there! 73, Charlie, K4OTV -----Original Message----- From: Topband [mailto:[email protected]] On Behalf Of Tom W8JI Sent: Wednesday, February 12, 2014 8:29 PM To: Charlie Cunningham; 'topband List' Subject: Re: Topband: Yikes! Heavy snow, freezing fog and 23 degrees F in Raleigh, NC > Gee, that should work great, Tom! How is the shaft rotatoion speed > controlled to maintain 60 Hz? > Tractors are like almost any other thing that has an engine and a manual throttle control, including lawn mowers. They have engine speed feedback that works like "mechanical ALC". It isn't like car or something that has an open loop system with a human stuck there pushing a pedal to regulate power with varying loads. If it didn't have that feedback system, a person would have to constantly adjust the throttle when mowing or plowing. I guess you could think of it like a cruise control, except unlike cruise it is the primary throttle and has wide dynamic range. Lawnmowers regulate the carburetor throttle plate with a connection to a flapper plate. Air from a finned wheel hits that plate. The plate works against a spring, and the throttle just changes spring tension. The tractors around here are a little more sophisticated, but same basic concept. They stay put pretty good. Within a Hz or so at the most. _________________ Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband
