Near Intersection of I-35 & I-90 Southern Mn. | 641cfrank - 4/21/2019 20:43
Is there any way to test the output from the two wires that it plugs into? I’ve had this problem before when I had it in servo mode running a raven valve.
For years, I installed a red and a green LED in Raven 440 type controllers when I worked as a Tech. This was just a pair of diodes with a current limiting resistor soldered back to back across the green and yellow wires inside the Raven. With my Ag Leader stuff I have sometimes used the same idea on Pins 2 & 7 out of the liquid module. I made a branch of those wires and ran the two wires to a connector. I used a small plastic box with a red and a green LED inside and a mating connector. This had to be done at the module so if the module is mounted on the implement, this might be a fair distance from the operator. Bigger LEDs or running the pair of wires closer to the tractor might make this easier to see.
With the controller set to standard control, the system should send out one polarity for Increase and the opposite polarity for Decrease so the LEDs allowed the operator to observe when the system was attempting to adjust. This was evident in automatic and also in Manual. I noticed somewhere where someone had used this idea with LED clearance lights normally used on a truck or trailer. Since these are polarity dependent they attached a red LED clearance light across the control pair which are green and yellow in a Raven harness. They attached a yellow clearance light to these wires also but in the opposite orientation. In other words a branch off the green wire went to the wire of one clearance light and the eyelet ground of the other. A branch off the yellow wire went to the eyelet of the first clearance light and the wire of the second. That meant that one clearance light was using green for power and yellow for ground, The other clearance light was using yellow for power and green for ground. It would be necessary that the clearance lights were insulated from the implement chassis. That should work fine but smaller LEDs in the cab may be a better plan.
This really worked quite well with a standard control. Sometimes, it might seem that the system is not doing its thing and trying to adjust the rate. Observing the LEDs would allow the operator to decide if the lack of control was due to the control circuit or something else (control valve, pump, plumbing or incorrect tips on a sprayer). The LEDs also work in the Fast mode that is needed with the Fast or Fast Close valves. There the LED flashes in quick shots. When the rate is low, the system should send a quick shot to increase the flow. What I observed was the system would often give two quick shots of Increase followed by a quick shot of Decrease. I assume this is to "put on the brakes" so that the Fast valve doesn't overshoot. With a Fast Close setup as used with NH3, the LEDs will show a constant Decrease when all sections are OFF as the system is then behaving as an ON/OFF valve.
The LED idea doesn't work so well with a PWM arrangement. I guess a single LED with a current limiting resistor to ground should be lit whenever the system is holding the valve somewhat open. The intensity of the LED should increase as the system opens the valve more but this might be rather difficult to judge. Since these shots are extremely short, the LED and human eye cannot react quick enough to catch the individual shots so we see this as varying degrees of intensity. Maybe this would be somewhat workable but a bit more confusing to interpret.
Edited by tedbear 4/22/2019 07:32
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PWM Liquid Pump Issues
