Monitoring Battery/Charge voltage for engine speed control

[thomasonw]

thomasonw,

I think the resistor divider should be calculated as 1.2 / (1.2 + 4.7) = 0.203; 1/0.203 = 4.92 : 1 (Instead of 3.9 : 1).

Maybe that was just a typo?

No, not a typo.  I had a brain-fade there and totally blew the resister divider formula...


Thanks for the catch!

-al-

[veggie]

Thomasonw,

Thanks for the the helpful advise on the divider.
While it may be useful in my application, there are many other reasons to construct such a circuit and have it ready in one's toolbox.
By turning battery voltage into a 0-5 vdc signal (or a 4-20ma signal) it makes it readable by most controller boards. The user may
control a multitude of things pertaining to the system.
Load diversion, low voltage shut down, lighting controls, solar panel alignment/tracking, etc...
For me, it just opens the door to more options.

veggie

[veggie]

The main job of my controller is actually to control a greenhouse environment.
The Laptop control software and I/O board will monitor temp, light, humidity, and then delegate commands to the sub-systems (solar, watering, engine heat capture, ventilation) to control the overall environment.
As an example, if I need the engine to run (low battery bank or a requirement for heat) the control software will close a circuit on the relay board and delegate the
starting to a dedicated off-the-shelf controller.
In this case an MTS-ECU-04 shown below ($190).
http://www.mtspowerproducts.com

This way I can control the sub-system (engine start/stop) with a simple relay closure from the main controller)

As mentioned earlier, by being able to read battery bank voltage as a 0-5v signal enables me to monitor many battery related variables other than just controlling engine speed for charging.

Thomasonw, I have been following your project. Very interesting !,... but I must admit it is far beyond my skill set to tackle such a project at the bare component level such as you are doing. Nice work.

cheers,
veggie

[Lloyd]

Veggie,

Here is an off the shelf auto gen start control, that is ready to auto start based on bat soc or inside temp.

Lloyd

http://www.magnumenergy.com/Literature/Manuals/AGS/64-0004%20Rev%20A%20ME-AGS-S.pdf

The main job of my controller is actually to control a greenhouse environment.
The Laptop control software and I/O board will monitor temp, light, humidity, and then delegate commands to the sub-systems (solar, watering, engine heat capture, ventilation) to control the overall environment.
As an example, if I need the engine to run (low battery bank or a requirement for heat) the control software will close a circuit on the relay board and delegate the
starting to a dedicated off-the-shelf controller.
In this case an MTS-ECU-04 shown below ($190).
http://www.mtspowerproducts.com

This way I can control the sub-system (engine start/stop) with a simple relay closure from the main controller)

As mentioned earlier, by being able to read battery bank voltage as a 0-5v signal enables me to monitor many battery related variables other than just controlling engine speed for charging.

Thomasonw, I have been following your project. Very interesting !,... but I must admit it is far beyond my skill set to tackle such a project at the bare component level such as you are doing. Nice work.

cheers,
veggie

[scottpeterd]

)Veggie,

Sorry  to jum topic here, but since you have the same 175/555 combo I've got, what combination of pulleys are you running?  I've got 4" on the engine and 3" on the alternator, and am spinning the 555 too slowly (engine at about 2300 RPM).  The 555 is running at about 3000 rpm, and it should be about 4500 to 5000.

Pete

[mobile_bob]

you need a 6 inch on the engine

or a 2 inch on the alternator, which is too small for any V belt and just under what a serpentine should run on.

if you are running at 2300rpm engine speed and your goal is 4500 you need to double the speed approx. which will get you to about 4600rpm.

i would save the alternator pulley and figure a way of mounting a larger engine pulley

imho
bob g

[Tom Reed]

Isn't there a stub shaft adapter for that engine? If so get one and any size pulley can be mounted. My n195 has a 12" pulley mounted.

[veggie]

)Veggie,

Sorry  to jum topic here, but since you have the same 175/555 combo I've got, what combination of pulleys are you running?  I've got 4" on the engine and 3" on the alternator, and am spinning the 555 too slowly (engine at about 2300 RPM).  The 555 is running at about 3000 rpm, and it should be about 4500 to 5000.

Pete

H Pete,

Engine      = 6"
Alternator = 5"
Ratio  1.2:1


Engine      Alternator 
RPM           RPM
==============

1500          1800
1800          2160
2300          2760

I can't really push more that 80 amps into my current battery bank so most of the time the engine will
be running between 1300 and 1700 rpm.

Below is my Leese BLD2380 performance curve mapped to the Changfa R175 rpm/HP

veggie

[Lloyd]

)Veggie,

Sorry  to jum topic here, but since you have the same 175/555 combo I've got, what combination of pulleys are you running?  I've got 4" on the engine and 3" on the alternator, and am spinning the 555 too slowly (engine at about 2300 RPM).  The 555 is running at about 3000 rpm, and it should be about 4500 to 5000.

Pete

H Pete,

Engine      = 6"
Alternator = 5"
Ratio  1.2:1


Engine      Alternator  
RPM           RPM
==============

1500          1800
1800          2160
2300          2760

I can't really push more that 80 amps into my current battery bank so most of the time the engine will
be running between 1300 and 1700 rpm.

Below is my Leese BLD2380 performance curve mapped to the Changfa R175 rpm/HP

veggie

veggie,

don't forget you have to map the torque of the driver to the torque of the load as well. The torque of the driver is rated at the shaft dimension, so is the torque of the load.

So you have to figure pulley diameter.

you can under-drive the load as long as you have excess HP and torque.

but where we are trying to match loads at the peak of eff...y, we have to value the torque, on both sides.

Lloyd