SIMPLE Polarity Reversing Switch


Introduction: SIMPLE Polarity Reversing Switch

First thing first, I KNOW there are other instractables for this, I just wanted to show my version. PLEASE don't flame because it's already been done!

Second, this is my first instructable. I have writen another but do not have a camera to take pictures with so cannot yet post it.

Third, this uses the simplest Double Pole Double Throw switch. This requires nothing more than the switch and some creative wiring. Please note that the "off" position only works if you have a "center off" switch! A DPDT relay can easily be substituted if you have one. If you want a 'struct' on this, leave me comments.

[EDIT, 3-28-'09] I have added some new information, please see the new step 4.

Step 1: Selecting Your Switch

You need to decide if you want to purchase a switch or salvage one from something else. if you purchase one, you have more options as there are many out there. if you salvage one you are limited to what you can find.

Make sure the switch you use can handle the amount of current you need
Decide if you want an off position or not.
Decide if you want a sliding switch, a toggle switch, rocker switch, or even a spring loaded switch that returns to off when released.
If there is a junk car around, check it for power window switches or electric seat adjusters. Both are most often DPDT switches, some are already set up to be inverting switches. Don't forget to steal the motors or sometimes linear actuators out of the seat adjusters, if you can!!!!
Broken stereos commonly have one or two switches in them

If you salvage a switch, the first thing I would do is test ACROSS the switch to be sure it is double pole. The switch has two rows of contacts with three pins per row. NO pin in one row should have continuity to ANY pin in the OTHER row. In the "center off" position, if equiped, NO TWO PINS should conduct.

In the case of a sliding switch: You should find that the center pin in each row conducts to the pin at the same end that the slider is on, but will not conduct to any other pin in the same row or to any pin in the other row.

In the case of a toggle switch: You should find that the center pin of each row conducts to the pin at the end OPPOSITE to the toggle lever, but will not conduct to any other pin in the same row or to any pin in the other row.

In the case of a rocker switch: You should find that the center pin in each row conducts to the pin at the same end of the switch as the RAISED side of the rocker, but will not conduct to any other pin in the same row or to any pin in the other row.

Step 2: Wiring the Switch

Wiring for this switch is deadly simple.

To make my instructions a little more easy to follow, hold your switch in such a way that you are looking at the pins and they are arranged 2 pins wide and three pins tall. Imagine that the pins are numbered as below:

1 4
2 5
3 6

Connect a wire from 3 to 4, and another wire from 1 to 6. These wires will form an "X" across the center of the switch. Only one of these wires needs to be insulated as long as both are too tight or too rigid to move and touch other pins!

In my diagram the source wires are the red and black wires connected to pins 3 and 6 and the load wires are connected to pins 2 and 5. there are many acceptable wiring methods though. Since there is nothing to restrict the flow through the switch, load and source can be swapped wihtout any problems. If one pair uses pins 2 and 5, the other pair can use 1 and 3, 1 and 4, 3 and 6, or 4 and 6, but not 1 and 6 or 3 and 4! I hope that was clear :P

Once your wiring is done, setting the switch will cut off power, allow it to pass through, or invert the polarity, respectively as shown in the diagrams below

Step 3: ENJOY, and Leave Me Comments

I hope you have enjoyed, and gotten something useful out of reading my first Instructable. Please leave comments if there was anything that was unclear or anything I should change as I will not know unless you tell me. Flames or non-constructive criticism WILL BE DELETED (if I have that option.. ignored otherwise).

Thanks for reading,

Step 4: Premade Switches

In household wiring, there is something called a 3-way switch. 3-way switches are used in pairs. You might have a pair in your house. If you have a switch at each end of a hallway that both control the same light in the hall, that's a 3 way switch set. Either switch will operate the light.

There is also a "4-Way" switch. If you needed 3 or more light switches for the same light, you would start with a 3-way pair and add a 4-way switch (as many as needed) in series between the 3'way switches.

After doing a little research, it has come to my attention that the individual 4-way switch does exactly what my 'ible shows. I would assume that being designed for 110-120 volts and capable of handling 500 or more watts, this switch would be useful in most DIY projects needing polarity reversal, and where physical size would not be a restriction.

If anyone can confirm or contest this, please do, as I have not had the money to go buy a 4 way switch to test it.




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    The attraction of opposite polarities is primary in God's universe. When people hear "the sixth sense" they think of something mystical, but, there is a real sixth sense that not all people notice: magnetism. Magnetic fluxes are closed circuits of the one substance, energy, in the one substance, energy. The most personal magnetic fluxes are the polarizations of the the iron in the cytochromes that close and open the doors of every cell. These fluxes, facing out, are counterclockwise in males, and, facing out, clockwise in females. The repulsion of like polarities clashing against their closed circuits is seen by many people as "flaming" white white light "brighter than the sun". This is caused by the repelling like polarities clashing against the closed circuits of the iron in the cytochromes of the cells of the optic nerves. Of course, it also causes magnetic stress in all the other cells causing other bad feelings. It was explained in a past issue of Discover Magazine that this sensitivity is the cause of a sense of direction. This explains the response to human polarities. Cells are so small that the physical human "aura" is a surrounding cloud of human cells. Everything in the universe is either composed of closed circuits, or is a closed circuit. Counterclockwise and clockwise are the only real polarities in the universe.

    Do NOT take anything from a junked car, that is theft !!! If the police catch you at best you will be ticketed, at worst arrested. If you don't have any switches just head over to a local Radio Shack, it you have one still around, or order some off the net.

    2 replies

    Ok, I realize that I did not specify in my article that you should obtain parts LEGALLY even from JUNK cars. If someone else owns the car ASK THEM, if you go to a junk yard, expect to pay!

    I also realize I actually said "Don't forget to steal the motors or sometimes linear actuators out of the seat adjusters, if you can!!!!" This WAS indeed a figure of speech. I do not condone ANY sort of theft, EVER, and to suggest or instruct any illegal activity on Instructables is against terms of service.



    I am trying to connect Audi A4 power seats to work in my 1964 El Camino. Each seat function motor has 2 terminals and in testing each motor when I put my 12v battery power to them the motor moves one way and when I reverse the pos & neg wires, it moves the opposite way. I cannot use the OE switches as the seats have airbags and I don't want to set them off accidentally so I want to install 6 dpdt switches, 3 for each seat. How do I wire them to the 2 terminals on each motor? I see how to wire the switch, but then what wires go to the motors?

    You are the man. If you're ever in Dallas I will make my boss by you 3 lap dances

    I want to make an automatic opening chicken coop door. I have a 12v motor and have a wire on a pulley to raise the door when a 12v timer activates. I want to put a high limit switch to stop the door when going up. When the timer goes off again at night I want to have a relay that switches the polarity on the motor so the door will close until it hits a low limit switch. Then switch back when the timer opens the next morning. Can you help me understand if this is possible, and how it would work? Thank you!

    Is it possible that there's a switch thats an on/off, switch polarity and at the same time a potentiometer??



    i needed to be able to revers polaritys for motors for a robotic hand idea. :) thanks

    That's called an H-bridge. (the circuit diagram would look like an h) i used to make these all the time to control small motors.

    4 replies

    ehhh... Hibridges usually have transistors or relays. Good instructable! I did something similar to this a couple of months ago when I made a solar car. The switch controlled the solar panels to either to be wired in series or parallel.

    Thank You both for posting. I was always under the impression that an H-Bridge was this sort of thing but done with FETs, not with actual mechanical switches... guyfrom7up, your comment touches on my next instructable, a wire harness for two motors (or batteries) to select between low and high speed (by putting either two motors or two batteries into series or parallel mode) as well as the reversing switch. DC Mike.

    This is what I was trying to get across in my instructable. Your assumption of the FETs is what the usual person thinks on these days, when actually its been done, simpler and less expensive than using many parts to do the same thing. We have to remember that electronics as we know it today is an evolution of the original stuff. Good to see you're thinking. Also, the wiring harness: think about the way a stun gun charges and discharges. One is in parallel the other is in series. You may want to try a watered down version for a quick kick in the motor (as long as it will withstand the kick!).

    For a female in the business end of the modeling industry I would be able to construct this switch blind. Some of our Mini Amps have a reverse polarity and thanx to you we now have or board wired to carry out this need. . . .it is dificult to believe that this was your frst presentation of this sort. Afte-thought: Have you ever done any modling. . .Hee Hee ..thanx Rose

    This works great for my colloidal silver generator where I use it to switch polarity on the electrodes. This allows me to get better use of both my electrodes and makes for a better finished product. Eventually I will look into something that I can use to do this automatically without any user intervention, hopefully something that will do this every three minutes or so until shutdown occurs.
    Thanks for a great instructable!

    2 replies

    you know, I posted this in 2008 and thought that with the other Ibles out there with better pictures and better instructions, no one would likely ever see this one. FIVE years later, I am very glad to know that it is STILL helping people!!!! I have especially had fun hearing HOW people have used them!!

    By the way, what exactly is a colloidal silver generator? :P


    I guess some things just don't change too much. You did a very clear and concise presentation of this and I found it at a time when i was just too tired to do my own thinking so it was very helpful as simple as it is.
    Colloidal silver is another one of those "crazy" ideas that freethinking fringe idiots like myself like to entertain themselves with. It's a "silver bullet" of sorts that big pharma doesn't want you to know about.
    It basically is a method for using electrolysis to form a water solution which is saturated with nano size particles and ions of PURE silver. It will turn you blue like the "Smurf man" and folks make claims that it can rejuvenate your sex life, make you live to be 100+ and all sorts of other strange things.
    In reality it will kill any bacteria that it comes into contact with very quickly. You can find a lot of junk science about it all over the internet but if you don't drown first you will eventually sort out the truth from the fiction and discover its true virtues.

    If I haven't scared you off yet you might start with this link to learn more.
    If you are still interested here is the best plans I've found for making your own generator as well as some other very good information, at least 95% of it.

    Long answer I know, but I just wanted to return the favor, especially since you asked.
    My son has been fighting MRSA in his leg for three years. Doctors have about worn out his immune system with antibiotics, etc.. I finally convinced him to try CS last month. All his outward symptoms have disappeared and he is convinced it is working for him. This is why we are building generator setup now.

    Got news two weeks ago that an old friend is about to meet their demise after a 13 year long bout with MRSA that was caught as a result of back surgery. I've suggested CS for this case but I don' t know if they will try it or if it's too late.
    The stuff works and is not dangerous if made and used properly. Hope you'll learn more from the links i posted above.
    Again, thanks for your help.

    Great info. Due to my lack of knowledge, you lost me on the alternate wiring scheme. But the initial crisscross plan makes sense to a rookie like me. I have a 110v hoist which I am converting to a luggage lift and need to incorporate two more controllers on each floor. From the source the WHT wire leads up to the motor, and a black wire is directed to the up/dwn controller w/ rocker switch. The rocker switch is wired differently. There are four wires connecting the switch. The BLK (hot wire?) Using your pin enumeration; is connected to pin #5 , a WHT wire from pin # 2 leads to a set of capacitors? A RED wire connected to the pin #6 runs to a limit switch (that cuts out power when the cable reaches the top) the same red wire from the limit switch joins with the wire from the capacitors, and continues to the motor. and finally a GRN wire joins pins 4, 1 and 3 then runs up to motor. My questions; are all DPDT rocker switches the same. If I find one (here in Mexico) could I simply splice in an additional two switches following the same schematics of the original switch? Thank you.

    I plan on using this for a simple robot where this would be applied for "feelers" where it would be going straight then when a feeler is pressed(via contact) it would reverse that motor causing it to turn away from object if it all works anyways ;) thanks and nice job