Need Help Wiring Remote Control Lawn Mower


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.


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You will need a relay to power the motor switch. You will need some additional circuitry between the digital port on the EZ-B and the relay. There are a few threads on the forum about how to wire this up. Do a search on: transistor relay switch and the most useful ones pop up.



Not to sound totally ignorant, but that flew right over my head. My knowledge is really in fabrication. I am learning more about the wiring etc but far from knowledgable


The gas briggs engine was originally an electric start engine that started off of turning a key switch on the mower. We need to delete the key switch and be able to start and turn off the gas engine via the DX5E controller. I was told that I could add a starter solenoid and wire a battle switch to the solenoid to start the engine, but what I am worried about is that the battle switch is a 10 amp switch. I was also told I could use the second battle switch to shut the motor down by wiring it to the original kill switch?
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?


I am not fully versed on electronics myself, but am researching the same thing for some of my bots components, so this is what I found. Basically, a relay can be used to switch a higher voltage or amperage from a low voltage or amperage signal source, so you would replace your switches with relays. The problem is that the ports on the EZ-B are too low amperage to directly drive a relay without burning out the board, so you need a transistor as an additional low to higher power switch (and probably a diode to further protect the EZ-B.

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 is right.

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
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What this does is, it takes the signal from the EZB and when a digital on command is given through EZ-Builder, 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;
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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


The Battle Switch can be activated from an EZ-B servo port. It uses a servo signal to activate it. I have one hooked to the AUX channel of my Spectrum DX6 rcvr and use the toggle switch on the transmitter to turn it on or off. Works great. Below is a copy of the description from the Robot Shop web site. You must make sure that 10A is enough for activating your starter motor . *EDIT* I mean the starter solenoid.

"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. "

Diagram from Dimension Engineering



I had not heard of a "Battle Switch". That sounds like a great solution.

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.



This is the switch/relay i was talking about... Will it work?