
real57vetteguy
Hi all,
This is a great forum and I am glad I found it!
I am working on a 4wd remote control mower build. Here is what I have:
20 hp electric start briggs gas engine
DX5E controller
2 battle switches
sabertooth 2x60 motor controller
2 x wheel chair motors
This is the second remote mower project, the first one turned out great but it did not have electric start or electric deck adjustment. I need help figuring out how to wire the starter to start the gas engine via the remote. I also need help wiring an electric screw jack to be able to adjust the deck height up and down via the remote control. Any help would be GREATLY appreciated.
Alan
As far as the electric screw jack its my understanding that I can use a double pole double throw relay to be able to adjust deck height? Am I on the right track?
There are some relays specifically designed for this kind of thing. If you look for Arduino relays you can find them, but I think you will spend less and learn more building the circuits yourself.
Hopefully someone else will chime in with more specific instructions.
Alan
Basically, and put in to layman's terms as best I can...
To switch something which uses higher current/power than the EZB you need to build a circuit.
First, you need to make the switching circuit, this is the TIP122 Darlington Transistor Circuit used for millions of reasons with the EZB. This is the typical diagram for this part of the circuit
What this does is, it takes the signal from the EZB and when a digital on command is given through ARC, EZ-Script, SDK or whatever you use, it will allow current flow from the VCC to the Ground.
The next part is to add in a relay to the circuit, you wont be connecting the above direct to the mower.
A relay basically allows low voltage, low current control circuits to control larger circuits. When the control circuit energises the relay it closes a switch allowing current to pass.
Sort of like this;
That should take care of activating the mower circuits from the EZB. Hopefully it was simple enough to understand how it all works...
For an example of how to use the EZB to switch 110v circuits check out Josh's Salt Water Tank project
"Relay can activate applications with voltage levels as high as 240VAC (10A @ 28VDC)
. Toggled via hobby radio control gear.
. Control powerful auxiliary weapons!
Dimension Engineering BattleSwitch Radio Controlled Relay is the larger, 10A version of the popular PicoSwitch (RB-Dim-02). BattleSwitch is a relay (SPDT) switch that you toggle via hobby radio control gear. You can use BattleSwitch to quickly and easily control glow plugs, BattleBot weaponry and more. You can activate applications with voltage levels as high as 240VAC without having to know anything about microcontroller logic levels or transistors because the relay offers full electrical isolation from your receiver electronics.
The Dimension Engineering BattleSwitch plugs into a standard hobby radio control receiver as easily as a servo does. You connect the load that you want to toggle using BattleSwitch's wear resistant screw terminals. Depending on the channel you use, you will then be able to control the relay by moving your radio's control stick up or down, left or right, or another method you desire.
BattleSwitch has a status LED on the bottom. The LED will light up when the relay switch is on, and vice versa. It will also tell you if your radio link is too weak by flashing repeatedly. The relay is a single pole double throw switch. Its typical lifetime is 100,000 switching cycles, depending on how heavy a load you are using. "
RobotShop.com
Diagram from Dimension Engineering
Dimension Engineering.com
Thanks Rich for the circuit diagram and explanation for using a transistor and relay too.
@jstarne1, if you are reading this, another couple of good posts for the Wiki.
Alan
http://www.robotshop.com/dimension-engineering-battle-switch-1.html
Thank you for the diagram. I am thinking I need to run a battle switch to the starter solenoid, then wire the solenoid to the starter?
This sounds correct. Do you own an ammeter? If you haven't disassembled the existing mower completely yet, you could measure the amps at the solenoid while starting the motor to make sure it is drawing less than 10 amps.
Does it start with a battery or a 120VAC plug today? If a battery, it is almost certainly less than 10 amps draw.
Alan
@ Alan 90 percent of meters out there under 300 bucks are fused at 10 amps max for measuring current load even the nicer "ideal" "snap on" and "fluke" brand meters its a standard limitation. Just wouldn't want someone to let the magic smoke out of their meter... It needs it after all lol
I can't complain though as it lasted me 26 years
I seen some robotic mowers on the net and it really only takes a hand full of parts to convert a mower to RC control.
I plan on using a regular mower, maybe if I had that machine shop you have I would go from scratch too
I was wondering how you plan on turning the mower as your wheels looked fixed?
I know one of the problem RC controlled mowers have is they don't run true.
Herr
Solid State Relay SSR
it can be wired right up to ezb
[URL=http://s825.photobucket.com/albums/zz175/real57vetteguy/?action=view¤t=2013-03-04_17-56-44_960_zpse2543408.mp4]
]video of mower
Some well over 35 amps and more and almost no heatsink is needed like with switching darlingtons
USED 100 WATTS mosfets without a heatsink for H-BRIDGE design
and not like switching transistors you can easy add in parallel to double the current rating
with switching transistors (darlingtons ) YOU NEED A FEW RESISTORS with mosfets none is needed
Second i am looking at building a robotic mower ,but with our gas for many reasons,need a very very big battery larger frame ,plus very powerfull drive motors
BUT still you project does look good
if using a 25 amp darlington switching circuit you will need a good size heat sink
IRFZ44 mosfet is so simple to use ,it hooks the same as switching darlington circuit and resistor value is same,and no heatsink is needed,plus no power is wasted
i see i am not the only one that doesnt use spell check and RICH has said to me a few times
One extra hint that I have used to help people who sometimes have trouble communicating in writing.. Read your posts out loud before you hit send and make sure they sound right. It can help when you are typing so fast you get your words out of order. Just reading silently doesn't seem to do it, but reading out loud you actually hear yourself and can notice more. (I planned on telling you this privately when I asked you to email me a few weeks ago, but you wouldn't, so here it is...).
Thanks for your recent information on mosfets. It led me to look up some information and they seem to be very useful.
Alan
This forum is first time i did any writing in over 20 years,never really had the need too.
I have a lot of work and dont really have the time to recheck my spelling or grammar and some is not needed ,like periods and capital letters
But my posts are getting better ,and most likely to make easy to understand them will do a few posts and not put many words in them.
Also of my words i use are very technical and most here dont know what it meens.
like RDS on mosfets not many knows what it meens .
MOST think i am wrong on the mosfets,yet i know more about them then most of the guys here .
Sorry to hear that you fried the battle switch. Did you ever identify a solution? Please post! I'm trying to do something similar. Thanks
However servo City has a good selection of wheels and tires that may be what youe looking for:
Off Road Rubber Tires
wheels
I have been playing around with the idea of another motor controller to operate the starter. I don't need the pwm though. A relay would probably be best, I know. Obviously, since the mower already has one, It's a matter of actuating it until the engine starts, then shutting it down. My system uses a 6v battery to start it. I can't tell you the amperage; haven't found any specs on it , and I haven't tested it yet. I am wondering if a LM298 motor controller could be used to actuate the relay? Especially since it is only 6v. Hearing he blew the battle switch, I'm afraid to try it on mine.
I haven't tried anything as of yet, due to lots of overtime at work and waiting for parts to arrive. But tomorrow I'm off and that is one of my top projects. I'm going to try the LM298 to see, unless someone has a better idea.
I am not sure how @real57vetteguy had his wiring hooked up but seems to me the Battle Switch should work fine to pull in the solenoid coil. The Battle Switch contacts are rated high enough to be used to activate the coil of the solenoid.