When you need to control a DC motor (such as a DC linear actuator) you usually need to be able to swap the polarity on the wires going to the motor.

A double pole, double throw switch is used for this purpose but you have to wire it up correctly to reverse the polarity going to the linear actuator.

Step 1: Required Materials

You need the following materials:

-DPDT rocker switch
-insulated disconnect terminals (female) x 6
-wire cutter/crimper/stripper tool
-a linear actuator or DC motor to control

Step 2: Connecting the Wires to the Disconnect Terminals

First you need to cut a bit off each wire that will be going to the motor. This is the jumper that will allow the polarity to swap.

I'm using blue and brown wire. THE COLOR OF THE WIRE IS NOT SIGNIFICANT. You can use red and black, or any combination of wire color. Because you'll be swapping the polarity back and forth on the actuator, the color of the wire, and whether they are on the right side or the left doesn't matter.

Twist together one end of the blue jumper wire and the end of the main blue wire. Then push this into the disconnect terminal and crimp with the wire tool.

Do the same for the brown wire.

At the end of the blue jumper attach another disconnect terminal.

Do the same for the brown wire.

Attach the main blue terminal to one of the poles on the side, attach the main brown termainl to the pole right next to it.

Attach the blue jumper connector to the opposite corner, and the brown jumper to the other corner to form an 'X' across the switch.

Step 3: Connecting the Wires to the Disconnect Terminals (for Power)

Similar to the last step take another wire that will go to the +12V DC (or whatever you are using). I am using blue wire.

Attach this to a disconnect terminal.

Do the same with another piece of wire (I used brown). This will go to ground.

Attach these to the center poles of the switch.

With my switch it doesn't matter which poles it's attached to, as there is no up and down for the switch. If you don't like it just turn the switch upside down. Otherwise test before installing the switch.

Step 4: Done!

Done! Now we can connect the power to the switch and wire the DC motor to the switch so it can reverse direction.

I use these for linear actuators (http://www.FirgelliAuto.com/), but you can just as easily use these for any DC motor where you need to reverse the polarity to change the direction of the motor.


Step 5: UPDATE: Wiring Diagram

I've had a number of people ask me about a wiring diagram, as the photos may not be enough on their own.

<p>I have a DPDT centre off switch that controls a model railway turntable - see attached image - and I want to add 2 LEDs to indicate direction of travel of the turntable either clockwise or anti-clockwise. How do I do this? I believe blocking diode/s can be used. I hope you can help. Thank you</p>
<p>This is very helpful, i did wiring like this and its work perfect on my actuators forward and reverse. great job buddy. i recommend to place clear images of after wiring.</p>
<p>Thx for the wiring diagram. totally what i was looking for and fixed my switch and things work great now.</p>
<p>My 4 pin switch has jumpers to the opposite corners, with the positive and negative terminals in the middle of the switch. Can this switch be used to wire the actuator?</p><p>Thanks.</p>
<p>Hi<br>there, I hope some one can help, I am trying to sort out some<br>controls for a wheelchair I am building, I have sorted out all the<br>actuators to run from separate rocker switches (4 x 6 pin DPDT) they<br>are powered from the on board 12v batteries 2x =24volts what I want<br>to do is try to find a way I can wire up several actuators (the same<br>ones I need with separate controls too) so I can press one button and<br>have the seat riser the foot rests and the strand function all work<br>from the one DPDT button as all are required to make the chair get in<br>to the stand position. The problem is I need to be able to<br>automatically isolate the power from the separate buttons just in<br>case I activate them by mistake at the same time thus causing Pos+ &amp;<br>Neg- being sent at the same time to the same connectors on the<br>actuators. As the functions are battery intensive it also needs to<br>operate from the on board batteries. Any help advice oh so welcome.</p>
<p>Thanks for this. Just added a forward reverse switch to a power wheels.</p>
<p>I built this using a toggle switch, so I could run a scavenged DC motor forwards and back, as a proof of concept. Me and my son are going to be building a toy car out of scavenged parts around the house. Oh, also, the power supply I used is a repurposed USB cable plugged into a 5v 1A device charger.</p>
<p>Excellent.: I applied this knowledge to a Ceiling Fan. This is exactly how the Reverse switch works on a Ceiling fan. Mine Broke and replaced the reverse switch for few bucks. Now the Ceiling Fan works like new. </p>
<p>i have something for yea i have 3 rocker switches running 2 jack motors (left &amp; right) I want my center rocker to run both motors at the same time i wired this all together and i get all power to both legs from every switch what have i done wrong or what is my next step?</p>
<p>Hi there. I have come this far but have hit a road block. I am trying to run a linear actuator with a wireless winch control i bought off of ebay. The actuator only has 2 leads and the wireless receiver works by sending power through one of 2 leads depending on if you press the up button or the down. Is there a way I can make this work? thanks in advance.</p>
<p>Are thease the power or motor wires ??</p>
<p>I would like to use an electric drill (corded) as an actuator drive.</p><p>Is it possible to replace the reverse polarity switch on the drill so that i can turn it on with a rocker or toggle switch?</p><p>I would really appreciate your help.</p><p>Thank you.</p>
<p>I have an actuator and a choice of 2 separate power supplies, ( A and B ). Each power supply is able to change direction of the actuator. I want to protect (B) from power being pushed into it, when (A) is activated. Is it possible to use diodes to accomplish this? What would be the diagram for this? Thank you, Mike mmdesperado2005@hotmail.com</p>
<p>Not sure I fully understand, but do you mean you are using one power source to extend the actuator and a different one to retract? This might be useful if you want to extend slowly and retract fast, or vice versa. Is this is not the case, let me know.</p>
1 - Calm down <br>2 - Wire your power sources in parallel
Please may I know .., how to wire a 3 pin toggle switch (on on) for reverse polority ? Thanks
the Terminal always choose the 6.3mm type
PLZ ANSWER QUICKLY!!!!!!!!! how do you wire 3 dpdt switches to 3 motors with 1 power source? <br>Thanks!
The center poles wiring is a tad confusing. &quot;Similar to the last step take another wire that will go to the +12V DC...&quot; for example as well as connecting to &quot;ground&quot;. Also, the instructions are not explicit regarding wiring to the motor. Overall, thanks though.
my dad knows alot about this stuff and so do i but im only fifteen and i wud have him help me but he leaves soon for fort benning, georgia for a year so youll have to bear with me here!!! this summer im going to build a model maglev train that runs recieves its power from a wind turbine im building and the wind turbine will power the electro magntes i want to build and put in the track. i want o be able to keep the car levitated but not moving when my system is off. i have a control panel devised to control the whole system and the track is divided up into ten sections. i want to go from the stepper motor in the wind turbine to a potentiometer to control the output of power to the rest of the system. the from the potentiometer i have it go to a switch the turns the whole system on and of and connects to an led to tell me if its on or not. going from the system switch i have it going to ten different potentiometers to control the power to each electromagnet. from those potientiometers i have them going to toggle switches one for each potentiometer that controls the power to the electromagnets in the track and they connect to leds to tell me if there on or not. each toggle switch connects to a section of the track witch each section will have at least 20 or more electromagnets. now heres where im stumbled... i want to be able to turn the electromagnets on and off, which ive already done, control their power level, which ive done, and change their polaritys from north to south at will, which i havnt done, and keep the car levitating while the electromagnets are off, which i havnt done. how will i connect from the section switches to a switch the will change the polarity of the electromagnets in each section and i want it to conrol every other electromagnet in the section so ill have to switches 1 for A magnets and 1 for B magnets how will i connect them to control the polarity? and finally how will i set the track up and system to keep the car levitating off the track while the electromagnets are off? oh yah and how will i build the electromagnets i was thinking of just running the current into small copper plates/peices to creat an electromagnet cause ive seen that be used as an electromagnet before and have done that in other projects but this is my most complex project yet and i want to do it right the first time around?... oh yah uhm each A magnet in a section will connect to each other and each B magnet in each section will connect to each other so keep that in mind when your figurin this out for me thanxs!!! so its such a long explanation just wanted to be as detailed as possible!!! :) thanxs alto guys
also whats ground means
Hey Luneydude. I am 15 years old as well, and I have learned all of this stuff from scratch, I knew how to do this stuff for 12 years. Anyway. Ground simply means the NEGATIVE (black) wire of your battery, or chassis in a vehicle. The only thing I know how to make via electromagnets are magnets that can lift up to 6600 lbs of weight with a 12 volt battery..
I know this is kind of old but I found it and it has been helpful but I'm still having a small problem. I have a DPDT switch hooked up to a DC motor with a Potentiometer in series to control the speed of the motor. The only problem is it only controls the speed of the motor in ONE direction. When I flip the switch to make the motor go in reverse, the motor just spins full speed with no control from the pot. Any thoughts? I can upload a diagram of how I have it wired but its an extremely crude diagram. I don't how to make a true electronic schematic with all the correct symbols.
try putting the potentiometer in before the dpdt switch, so the power goes potentiometer --&gt; switch --&gt; motor instead of switch --&gt; potentiometer --&gt; motor
Thanks so much Troy! It works great. I am using it to control a 12v. power window motor to raise and lower a shelf. I soldered in the switching diodes I purchased at Radio Shack to the limit switches. Bingo! It works... once. I'm afraid the amperage is too high to the RS diode. What do you think? Where can I get higher rated diodes? Mark
Hi very usefull instructable. Would anyone know how to wire these so two switches can be used to do the same thing, similar to a light switch upstairs and downstsirs that both control one light??
&nbsp;Hi! i want to use a micro switch to reverse the polarity on the dc motor instead of using a dpdt rocker switch. please advice me on what to do. a circuit diagram will be highly appreciated.<br /> Thanks!
i am remote controling a powerwheels and i needed this wiring diagram forever&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br /> <br /> thanks
Troy, I think your wiring diagram is either lacking "COM/NC/NO" labels, or is reversed. I've used this scheme myself many times, and that diagram looks like the NC and COM terminals are backward. The one I've used is: Supply (+) to NC(a) and NO(b) Supply (-) to NO(a) and NC(b) Actuator (+) to COM(a), and finally, Actuator (-) to COM(b). Thanks for posting!
PS.: I was intending for the motor to be stopped or off whenever the lever is in the center position and for the lever to make it go clock or counter-clockwise depending on which is depressed, like a remote control for a rc car.<br />
I realize your comment was made year and a half ago, however I have a problem with your diagram and it would be nice if you could help me solve it. The problem is that I've got two switches such as the microswitch on the special switches section from this page http://www.kpsec.freeuk.com/components/switch.htm. they're setup one facing the other with a lever in between both, the thing is that when none of them are depressed the motor runs and by depressing either one of them it stops. Thanks in advance for your advice.<br />
thanx to d&nbsp;labeled circuit diagram fom::::department_g33k<br /> <br /> though the basic diag too is well undrstood
Hi there, thanks for that - what diodes do i need i'm using a superjack linear actuator (DC) and a 36volt power supply
Not 100% sure, you can go to DigiKey.com or Mouser.com and ask them for a diode that can handle > 36VDC and whatever amps your actuator pulls. I dont know which diode off-hand..
Hi i want to use this to power an actuator with a throw of about 18" or so that will raise a tabletop platform - how can i introduce two limit switches to stop it at the top and bottom of its path of travel, i've tried sketching it out (so i dont reverse polarity anything) but i just cant get my head round it! Any help - especially in schematic form - would be greatly appreciated. thanks
You would have two micro switches with diode wired inline with the actuator motor.
If using a simple double pole-double throw (i.e.. two position) instead of using a 'center-off' type switch, It might pay to check that the contacts are described as 'Break-before-Make' and definitely not 'Make-before-Break' Using the later type would put a short circuit across the power supply each time the switch is toggled!
I have a question about dpdt switches. What happens when the switch is in the center position? Does the motor "hold position" or is it just off and freewheeling? Do I need a center on dpdt switch to hold the motor in position? Ive been surfing around and seen dpdt center on here and there..but I can't find any info as to what center on actually is...heh Obviously in a servo or gearmotor you would want the motor to hold position when the switch was centered Any light on this would be greatly appreciated
thanks for posting. Do anyone knows, are both the jumpers for reverse polarity. Which brand switch to use if I want one jumper for forward and other jumper for reverse. I know this will work, so need suggestion.
Troy, great diagram for the switches I purchased at my local hardware store. Took me 30 mins to wire up two motors. They work great. Thanks for the posting
I used a similar wiring to use 4 Ford starter relays to make a corded remote control switch for a 12VDC winch used on a pick up boom hoist. The reason I chose those in because I could walk into any supply store and buy them off the shelf, and at that time they where less than $5 each Yes the relays aren't duty rated for such use, but in nearly 10 years of daily use there were no relay failures. These days I would build a wireless remote in addition to the corded remote. The only way I can see how to improve your instructable is to add a wiring schematic to aid those anyone can't see how this actually works, to figure it out by tracing the current paths.
In his book, "Robot Builder's Bonanza," Gordon McComb has a lot of little tricks like this one. Most of the designs are outdated as the book was written in the '80's, however the concepts can be easily updated with more modern components. He also has several other books.
I have the 3rd edition in my hand right now. It was published in 2006. Most of the stuff in it is common, but there are also things like fiber optic whiskers.
I have the second edition, which is really just a second printing of the original book. I looked up the 3rd ed. on Amazon, and it looks like a lot of time was spent updating it and adding new things. Perhaps its worth it for me to buy the new one, though I liked the old yellow-and-blue cover better.
This is pretty darn close to 'True Bypass' on guitar FX pedals ...
nicely done...easy to understand
Thanks alot for this, ive been trying to figure out how to do it :D
me too
Good job.
Nicely and neatly done. You can do this with a DPDT relay as well, and get electrical control of direction.

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