diesel engine governor
splog
Posts: 3
Thanks to all that answered my cry for help.
Sorry but I suppose I was not too clear about my quest.
JIM
Your engine most likely has a built in governor on it, that’s why it holds its rpm once you have set it. Mine is an old Universal model – 15 without governor.
Governor
The engine does not have any type of governor on it, it will have to be controlled using a small gear motor to drive the throttle shaft cw or ccw in order to keep the engine running at a speed (approx 1800rpm) that will result in the generator head delivering 250vac at 60Hz.
Generator
The generator is a standard four pole ST-12 type. In my case it’s a 12Kw I know I can get at least 5Kw out of it.
Frequency
My VOM has a freq. Meter built in for this and anyway generally speaking when the generator is putting out the right voltage the freq. Is very close to 60hz.
Spring on the throttle
This is a good idea but I think that if I use a gear motor the spring might not be able to pull the shaft back down.
My aim
To have something, either voltage comparator or frq. Detector (perhaps a Schmitt trigger) that generates an output to a motor driver (H bridge or such) that turns an engine throttle shaft until the output from the generator matches a set reference equivalent to 250vac or 60Hz whichever will be the simplest..to null out the input.
What I don’t want to do
Re-invent the wheel. I have scoured the net and found a few already made electronic governors for sale but they all cost more money to buy than I have spent on the gen-set to-date, including welding rods and mistakes. There are plenty of motor driver circuits out there including Stamps but no actual examples of input circuits.
Sorry but I suppose I was not too clear about my quest.
JIM
Your engine most likely has a built in governor on it, that’s why it holds its rpm once you have set it. Mine is an old Universal model – 15 without governor.
Governor
The engine does not have any type of governor on it, it will have to be controlled using a small gear motor to drive the throttle shaft cw or ccw in order to keep the engine running at a speed (approx 1800rpm) that will result in the generator head delivering 250vac at 60Hz.
Generator
The generator is a standard four pole ST-12 type. In my case it’s a 12Kw I know I can get at least 5Kw out of it.
Frequency
My VOM has a freq. Meter built in for this and anyway generally speaking when the generator is putting out the right voltage the freq. Is very close to 60hz.
Spring on the throttle
This is a good idea but I think that if I use a gear motor the spring might not be able to pull the shaft back down.
My aim
To have something, either voltage comparator or frq. Detector (perhaps a Schmitt trigger) that generates an output to a motor driver (H bridge or such) that turns an engine throttle shaft until the output from the generator matches a set reference equivalent to 250vac or 60Hz whichever will be the simplest..to null out the input.
What I don’t want to do
Re-invent the wheel. I have scoured the net and found a few already made electronic governors for sale but they all cost more money to buy than I have spent on the gen-set to-date, including welding rods and mistakes. There are plenty of motor driver circuits out there including Stamps but no actual examples of input circuits.
Comments
But I was about to experiment with a system to ramp it up on demand.Would a standard servo work out somehow?If so,then an input to the Stamp could be taken from gen output.Try a simple wall transformer,5VDC.The variation in the voltage from the transformer corresponds to the engine speed.One might write a simple set of IF-THEN instructions to direct the servo position ,and consequently maintain the desired gen voltage.I wrote a BS2 program to do that if ever needed.
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Thanks, Parallax!
I suspect your A/C generator already has a voltage regulator, so you would only need to control the motor speed.
You mentioned a 5kW electrical load. This is about 6.7 hp or about 55% of the deisel rating. The diesel may not slow down very much under that load.
If this is for backup power you probably don't even need a speed regulator. Just keep a wrench or screw driver near the diesel and adjust the speed manually if there is a big change in electrical load. Ignore fluctuations of a few hertz unless you have some crital piece of equipment that needs a steady 60Hz (in which can you probably wouldn't be powering it from a home brew DG-set).
I put together a web page describing the system, which is Stamp-based, including a schematic and source code.· See http://www.kinzers.com/don/GenSet
You can build a selectable load using the large burners for an electric range.· I have six of them set up so they are individually switchable to allow me to test the generator.· I think that I paid $2-3 each for the elements at a used appliance store.
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Don Kinzer
http://www.zbasic.net
Post Edited (Don) : 11/22/2005 3:41:35 AM GMT