Posted 3/16/2020 07:57 (#8109065 - in reply to #8108187) Subject: Some other thoughts
Southern Minnesota Between Freeborn & Wells
Busted Knuckles - 3/15/2020 20:31
catmendoo - 3/15/2020 19:24 I would go with the idea of a pressure switch on each boom section to operate the light.
what do people feel would be the life of a pressure switch exposed to chemicals? (they are relatively inexpensive though)
The early Raven Injection pumps used an inline flow switch to warn of problems. This consisted of a device with a pair of wires on it. When there was flow, an internal ball moved and completed a circuit. Without flow an internal spring was supposed to push the ball back and the circuit was not complete. This seemed like a simple enough approach but it was not reliable as often the ball would "stick" in the flow position and would not break the circuit thus giving a false positive.
A pressure transducer in each boom might be a workable situation. It would seem possible to use one of these in each boom to provide an Input to one of the Arduino boards that I have been playing with. The boards can accept several analog inputs. The boards are cheap enough but the pressure transducers I've seen are fairly expensive.
What I envision would be a pressure transducer tee'd into each boom section with a set of three wires from each leading to the cab. One wire would be power out, another ground out and the third the analog signal back. In the cab the signal wires would connect as inputs to the Arduino. The program or sketch as they are called can convert these analog values to a pressure reading. This pressure reading could be displayed on a small screen. Another possibility would be to have it light up an Indicator for each boom when the pressure reached a certain value. It would be possible to use a multiple LED display so that the pressure would show as a vertical bar graph of each section. Once the information is inside the Arduino it could be used for most any purpose one could think of as far as a warning. This sounds like a potential project for next Winter, if for nothing else as a mental exercise.
I did a search on pressure transducers and found the prices vary greatly. The cheaper ones do not list chemicals so using them might not be a good idea. Yet on the other hand they are more tolerable in price and possibly buying some spares might be a workable arrangement. Rinsing the booms out is probably a good idea anyway, they might last quite a long time. The cheaper ones would probably not be terribly accurate but this is not really a major concern.
My ball valves happen to be visible from the cab. Maybe a clever placement of a camera or mirrors might make direct viewing of the valve indicators easier. Is your wiring as far as ground and 12V power of sufficient size? My Banjos on my planter are quite a distance from the tractor but I haven't had your problem. However, due to mostly rectangular fields mine do not cycle as often as you describe.