Near Intersection of I-35 & I-90 Southern Mn. | Josh4520 - 12/5/2024 07:12
I see what you are saying on the volume. It looks like I need about twice the flow of ravens large pump.
I guess what I’m really asking
Has anyone ever made their own pump? If I understand the Raven pump, it appears to be 12v. Looks like the 12v is supplied by a heavier gauge harness outside of the ag leader harness. The 2 prong motor connection of the Agleader harness the supplies a pwm signal to speed the motor up and down similar to how the liquid module works on a hydraulic drive pump.
I wouldn’t be so interested in this module, but I got one in a bundle at an auction. Just had another one of my “ideas “.
Your thinking is correct, I will add a few comments.
Has anyone made their own pump? If you mean used the Injection module to control something other than Raven's Injection pump, I would say "Not to my knowledge" but it may be possible. There are a couple of obstacles to work around.
The Raven pump is a two cylinder positive displacement pump. It is driven directly by a 12VDC motor in the High Volume arrangement. A gear box is used between the 12VDC motor and the pump for the ultra low volume arrangement. In other words the pump literally just runs proportionately slower.
Since the pump is a positive displacement pump, the output of the pump is directly proportional to the pump speed assuming the pump components such as check valves etc. are in good condition. If you would graph the output of the pump against the pump speed, the graph would be linear. Within reason, doubling the pump speed, doubles the pump output. This is not the case with other styles of pumps. The output of a centrifugal pump versus shaft speed is far from linear.
This means that the output of a positive displacement pump can be predicted by observing and changing the speed of the pump. One way to change the speed of the pump is to use Pulse Width Modulation to change the speed of the motor.
As you have observed, the motor connector from the Injection Module has a large two conductor plug and heavy wires. One of those wires is connected directly to +12V from the vehicle battery, The other wire is the ground which is controlled by the Module. The system cycles the ground wire ON/OFF to run the pump. If the module does not complete ground, the motor and pump do not run. If the module connects ground continuously the motor and pump would run at full speed. In normal operation, the ground is cycling ON/OFF rapidly and motor/pump runs at a speed somewhere in between.
The Injection module has an input from a speed sensor on the pump. This sensor senses the speed that the pump is turning. This is the equivalent of a flow meter in a larger system. This is the method Raven uses to determine the output of the pump since a flow meter capable of measuring low flows has problems of its own.
You compare the operation of the Injection module to that of running a Liquid Product Control Module in PWM. You are correct in that the concept is the same. Both systems use an input (flow meter or shaft sensor) to determine the volume of product currently being dispensed. By doing some math involving the meter cal, equipment width, ground speed, target rate etc., the system can decide if the output is within tolerance. If not, it changes the width of the Pulse in an attempt to run the motor/pump at an appropriate speed.
The PWM circuitry in the Injection Module is much heavier duty than that in the Liquid Module since the anticipated load of the injection pump is greater. The Injection module also includes some other circuitry to warn the operator when the pump is not pumping (empty tank etc.) or drawing excessive vacuum (plugged inlet in the tank etc.)
You ask about repurposing the Injection Module for other uses now that you have one. The Injection module could be used in place of a liquid product control module set in PWM mode. In fact it has the heavier circuitry so it could run a fairly heavy duty 12VDC pump without the need of an intermediate motor driver as is often necessary. The injection module has an input for a Vac sensor. This could be jumpered. It also has an input for a Flow alarm. Working around this would be more difficult since the Injection Module expects that signal to go ON/OFF as the pistons move creating cross flow pressure between the two cylinders. A fake circuit would be needed to create an alternating pulse to fool that portion of the system.
Finding a good use for your acquired Injection Module may be possible but has some limitations.
Edited by tedbear 12/5/2024 10:22
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Tedbear- ? On AgLeader Injection Module
