Posted 11/10/2023 06:47 (#10476099 - in reply to #10475798) Subject: Your thinking is correct.
Near Intersection of I-35 & I-90 Southern Mn.
ecil89 - 11/9/2023 21:14
I am or at least was planning to use a clutch control module to run the half width clutches on my 1770. My concern is that, after doing some research, the module needs to sense the clutches to work. I understand that the module switches ground rather than power to stop the section from planting. Currently, I have toggle switches in the cab that I use to power each clutch to stop planting. To accomplish this without rewiring the planter I was planning to use the exiting frame ground on each clutch and use a spdt relay powered by battery + and using the clutch control ground signal to activate the relay, and ultimately powering the clutch to stop planting. By not using the clutch control power output, will the module be satisfied that a clutch is attached? I am concerned (although maybe unnecessarily) that the power demands of the half width clutches is more than the module can or at least should provide. It's difficult to describe exactly what I'm doing, hopefully this makes sense.
What you are describing makes perfect sense to me. Your concerns are warranted and correct. I believe you have a good understanding of the situation.
You mention using a SPDT relay. For most planters, a SPST relay would be adequate since most half width disconnects use a completed circuit to STOP planting. I have heard of a few planters or drills that use a completed circuit to engage the planting units. In those rather rare situations, the SPDT relay could be used to reverse the logic of the Clutch Control Module. My comments below will use the assumption that your half width disconnect clutches use a completed circuit to STOP planting.
You are correct that the Ag Leader (and almost all other brands) use a completed circuit to activate a clutch (air, electric, etc.) in a manner to STOP planting. This is the reverse logic of a spray controller where a complete circuit is used to open a valve to ALLOW application. Again I repeat, the Clutch Control module completes the circuit to a clutch when it believes that planting with a section should NOT take place. This might be due to the fact that the system notes that an area has already been planted (most common) or that the operator has shut off the section switch assigned to that section.
Several different styles of clutches can be used. My first planter with section control used the Tru-Count air system. My Clutch Control module activated the coils of air valves which in turn allowed air to flow to the air clutches for that section to disengage the drive(s) for those rows. My current planter uses Ag Leader Sure Vacs in my Deere 1770 Vac planter. With this style, my Clutch Control Module (same one as before) activates the coil in the SureVac assemblies to move a plunger which blocks off the vacuum on the seed disks. Other styles have different arrangements but in each case a coil is involved which completes the circuit which causes the clutch to become active and STOP planting in a section.
To complete a circuit, a switch could be placed in the "hot" side or the "ground" side. Most folks would assume as I did that the switching would be done on the "hot" side. This is what you are likely doing with your current manual system. Your switch box likely contains two switches that are powered by a 12V source. Each switch leads to your half width disconnect clutches on the planter. The half width disconnect clutches are grounded back to the tractor through the frame or some other connection. You flip the switch ON to activate a half width disconnect to STOP planting for that half. This is assuming your half width disconnects, STOP planting with a completed circuit.
Ag Leader has chosen to complete the circuit to STOP planting by completing the ground side of the circuit for each switch instead of switching the "hot" side. That works fine, but may confuse the thought process.
At first thought, it would seem that one could just replace the manual switch box with the Clutch Control Module. The problem is that the Clutch Control module has current limitations. In general, it is not capable of working with the higher current demands of the half width disconnect clutches already on your planter.
This is where a relay for each half comes in. The Clutch Control Module can easily handle the electrical load of relays which in turn handle the actual load of working the half width disconnects. A SPST 12V Heavy Duty relay can be used with each half width disconnect clutch. These relays will have four terminals. One pair is for the coil, the other pair are Normally Open, but become closed or connected when the relay becomes active.
You mention that by using a relay your are concerned that the Ag Leader system will complain about a mismatch since it is not directly connected to the clutches. Your concern is warranted but is not a problem because the coil in each relay will be equivalent to the coil in an actual clutch .
Here's basically how this works. When you create a configuration in your Ag Leader display to work with planter or drill sections, you are asked to provide information such as number of sections, row widths etc. Upon initial startup for the day and throughout the day, the system will perform a comparison between the number of sections specified in the configuration and the actual number of sections and their locations that it finds on your planter or drill. If there is any type of mismatch as far as the number of section clutches or the location of these section clutches, the system will complain and refuse to proceed. This is because there could be major problems with a mismatch. This forces the operator to investigate and correct the mismatch.
This is where providing 12V to each clutch and completing ground to STOP planting comes in. With the clutches inactive (planting), the ground circuit is not completed. This means that 12V would be present on the ground side of each clutch since the coil is just an extremely long piece of wire. The system "looks" for 12V on the Clutch section return wires. If it senses 12V, it makes the assumption that a clutch is present for that section. It does this for all 12 potential sections and compares the result to the Clutch Configuration. If there is not an exact match, an error message is displayed.
So in your case, you would create a configuration with two sections. Connect a constant (or key switched) 12V source to the coil of each relay. Connect the Section 1 wire from the Clutch Module to the other coil terminal of the relay for the left side. Connect the Section 2 wire from the Clutch Module to the other coil terminal for the relay for the right side. Then when the system does the match/no match test, it will determine that a clutch is present on Sections 1 and 2 only which should agree with the configuration.
Then the relays should behave properly and complete the high current circuits to disengage the half width disconnects as needed.
It might be desirable to add a direct ground between the planter and tractor since some combinations just use the physical contact at the hitch for the ground path. This may not make for a good ground connection.