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Ravens monitor and cooler
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tedbear
Posted 2/15/2021 09:36 (#8833786 - in reply to #8832576)
Subject: RE: Raven Controller and heat exchanger


Near Intersection of I-35 & I-90 Southern Mn.
BeerBudgetFarms - 2/14/2021 19:04

We are stepping up in the anhydrous equipment. The new possible bar has ravens cooler and a 4500 monitor it gonna be pulled with a caseih 7140 how do we set the rates is ot by radar gps. Need help to understand and to know how expensive this could get thanks


Not quite sure what you mean but I assume you are saying that your tractor doesn't have GPS or a real radar gun to use as a speed input. I'm also fairly certain that the monitor you mention is actually a Raven 450 controller.

Your choices are: 1) get a GPS speed only device and slap it on top of the tractor cab. 2) get a more sophisticated GPS system than provides speed out but also could be used for other things such as steering the tractor in the future 3) install a real radar gun on the tractor 4) install a ground speed sensor on a non-driven wheel (front) on the tractor or applicator or 5) enter is a manual or test speed into the controller.

For your situation I would recommend going with #1 above. These units are relatively inexpensive. They typically have a magnet on their base so they can be stuck on top of a tractor cab. If the cab is not metal, a metal plate can be attached with double faced tape. The cable is run inside to the controller and plugged in. There will be a suggested calibration number shown somewhere on the device which is entered into the controller.

The ground speed sensor #4 is another choice. This requires a bit more work for installation and routing the cable to the controller. The other choices are viable as well but may not fit your situation. Using choice #5 with a manual speed is usually reserved for testing or in an emergency situation. It is not recommended to be used in normal operation.

Here's some basics of how controllers and monitors work. A monitor just shows you what you are doing while a controller is more complex. A controller shows what you are doing and can attempt to control it for you.

All controllers/monitors need some type of speed input. This is necessary so they can show the ground speed but more importantly compute the amount of land you are covering in a unit of time such as area/hr.

All controllers/monitors also need a way to compute how much product is being applied. This can be done in a variety of ways but for spray or NH3, a turbine flow meter is usually used. The product flows through the flow meter and turns a turbine that has magnets in it. These magnets pass by a sensor and deliver shorting pulses to the controller. The controller uses a calibration number to convert those pulses to common units such as gallons. It can also compute the Volume/min being delivered such as gallons/minute.

By using the Area/hr AND the Volume/min, the system can compute the applied rate such as Gallons/acre. It recalculates this every second or so while applying. If automatic operation is selected, the system compares the target rate that the operator has entered and the results of its calculations as far as what is being applied. If they are not in close agreement, it will send corrective action to the control valve to either increase or decrease the flow getting to the ground. If manual operation is selected the operator makes the decision as far as if and when corrective action is needed.

For realistic operation your system must have some type of speed input. Historically it went like this.

A magnetic speed sensor was mounted on a non-driven wheel of the tractor or applicator. These work under the same principle as the turbine in the flow meter. That is as the wheel turns magnets mounted on it pass by a sensor to produce shorting pulses indicative of the speed. A calibration number is used which is dependent on the size of the wheel and number of magnets. Early controllers pretty much all used this approach. These magnetic speed sensors are still available and work well. The biggest problem with them is that their cables can get damaged due to mud, debris etc.

As electronics progressed through time, radar guns became popular especially for planter monitors that need a speed input. These radar guns can be used as a speed input device for many things such as monitor/controllers and the tractor dash.

Later still, GPS systems that can compute Latitude and Longitude were developed. This information is used for mapping. Many, but not all of them had a speed output branch that could be used instead of a real radar gun.

A further development was the GPS speed only devices. These are cheaper than the more complex systems and only produce the radar like output. They do not produce the Lat/Lon information but output a radar like signal. They are wired to plug right into the speed port although sometimes an adapter is needed.



Edited by tedbear 2/15/2021 10:42
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