As far as slide switches go, I HAVE seen spring loaded "Multi-Function" switches. I've seen those in things like tape players, Cassette and Reel to Reel. These "MF" switches (not to be confused with "Mo-Fo") were on the order of several if not tens of contacts (i.e. 20 lead beasts) and they are not small for sure. 3 to 4 inches long, 3/16" to 1/4" wide and about as high.

If you were to go with momentary push button switches each switch would need to be SPDT. I could bang out a drawing in a few minutes. But I'm still wondering about the functioning of the project. Reversible motors that only run when a switch is in one position or the other but not run when the switch is in the neutral position.

 

Running in one or the other and stopped when released includes my power screwdriver and my general "power tool drive", and even my electric drill motor. And also at least one powered drain snake. And the windows and the seats on my cars.

 

Late entry here:


As others have said, finding a toggle [edit - slide] with center off AND spring loaded isn't something I've ever seen. Perhaps a specialty item might be able to be found but it doesn't seem to be something often used in commercial or hobbiest projects. Slide switches are even harder to find in a spring loaded configuration.

Your comments foster the question: "Do you want to be able to reverse the motor(s) only momentary? A momentary switch will only run the motor while holding the switch in THAT position. Letting go of the switch would seem to mean the motor has stopped running.

You also asked if there is a two button configuration that can do the same thing. I'm fairly confident there is one, though a solution doesn't readily come to mind. And I believe there's a chance that pressing both buttons at the same time could result in a short circuit, and that may blow your fuse - if fused at all. If no fuse you could damage your battery.

Thanks for the information. I need to reverse polarity only while the switch is being held in that position and using only one DPDT Switch. That is why I was hoping for a Slide switch but can certainly use a Toggle Switch too.

I am assuming that the MON-Off-MOM switch wiring is the same as it was in the first posted reply to this thread ut please let me know if it would be different for a MOM/OFF/MOM switch.

Joe

 

Here's a 2 button solution:

SW1 (mom) is a Momentary Push Button with Common wired to the motor (left)
SW2 (mom) is a Momentary Push Button with Common wired to the motor (right)
In Diagram A the dashed line indicates no rotation. The motor is dynamically locked (shorted)
In Diagram B the arched line indicates clockwise rotation (depending on how your motor is manufactured)
In Diagram C the arched line indicates COUNTER clockwise rotation

If both buttons are pressed at the same time the motor becomes dynamically locked.

Dynamic locking is when a permanent magnet DC motor leads are shorted together. The motor becomes a generator and the short circuit stalls the motor. It's called dynamic braking. Dynamic braking is usually done with resistors so that the motor isn't slammed with full current for that moment until the motor stops spinning.

And I'm going to ask it again: How are you using this? The motor only runs while you hold one button or the other. The moment you release a button the motor stops instantly (sort-a).

 

Posted while I was authoring post #24

Thanks for the information. I need to reverse polarity only while the switch is being held in that position and using only one DPDT Switch. That is why I was hoping for a Slide switch but can certainly use a Toggle Switch too.

I need to reverse polarity only while the switch is being held in that position and using only one DPDT Switch.
Actual purpose is still unclear (to me). Is this a running motor and you only want to momentarily reverse it?

 

I am assuming that the MOM-Off-MOM switch wiring is the same as it was in the first posted reply to this thread ut please let me know if it would be different for a MOM/OFF/MOM switch.

Yes, wiring is the same as in post #2.
I HAVE seen DPDT Center Off switches with one side being spring loaded (MOM-Off-ON) meaning you will get a momentary reversal while holding the switch. In the center position the motor is off and in the ON position the motor is on normal direction.

Is that where we're trying to get to?

 

Here's a 2 button solution:

SW1 (mom) is a Momentary Push Button with Common wired to the motor (left)
SW2 (mom) is a Momentary Push Button with Common wired to the motor (right)
In Diagram A the dashed line indicates no rotation. The motor is dynamically locked (shorted)
In Diagram B the arched line indicates clockwise rotation (depending on how your motor is manufactured)
In Diagram C the arched line indicates COUNTER clockwise rotation
View attachment 342217
If both buttons are pressed at the same time the motor becomes dynamically locked.

Dynamic locking is when a permanent magnet DC motor leads are shorted together. The motor becomes a generator and the short circuit stalls the motor. It's called dynamic braking. Dynamic braking is usually done with resistors so that the motor isn't slammed with full current for that moment until the motor stops spinning.

And I'm going to ask it again: How are you using this? The motors only run while you hold one button or the other. The moment you release a button the motor stops instantly (sort-a).

Hi Tony

I am using this to reverse polarity/direction of a miniature RC Car Motor. It needs to be normally OFF unless pushed in one or the other direction. It has to be a One Switch Installation which is why I am hoping that the DPDT Switch MOM/OFF/MOM will do the trick.

Joe

 

THANK YOU Tony!! Very good graphics to show what I described in post #19.
Besides being smaller, most toggle switches are much better quality than slide switches, AND they are more protected from contamination as well.

 

THANK YOU Tony!! Very good graphics to show what I described in post #19.
Besides being smaller, most toggle switches are much better quality than slide switches, AND they are more protected from contamination as well.

Thanks for all your help MisterBill2

 

@MisterBill2 Sorry bro, I missed that. Yes, you described exactly what I eventually drew out. Didn't mean to steal credit for your work.

 

It needs to be normally OFF unless pushed in one or the other direction. It has to be a One Switch Installation which is why I am hoping that the DPDT Switch MOM/OFF/MOM will do the trick.

OK, thanks for that clarification. Yes, a spring loaded ON-OFF-ON switch will work. As long as you can find one small enough to suit your purposes.

 

For the switch that the TS is seeking I suggest looking in the DIGIKEY 0online catalog. They are an HONEST and reliable company with no surprises or fake products. That is worth a bit. AND an actually truthful bunch of real product descriptions, instead of glittering generalities.

 

Since I enjoy drawing - and have standard drawings of toggle switches, this thread has prompted me to make a few more additions to my library. Below you see an ON - OFF - Momentary switch and a Momentary OFF Momentary switch. The spring is located inside the toggle handle. Its pressure on the rocker either locks the switch in a given position OR if the angle is sufficient it produces a momentary switch function.

Here's a standard SPDT switch with center off:

The spring is in the toggle itself. I don't know - or think - they can put a strong enough spring that is small enough to do the same function in a mini-toggle as they do in a standard toggle. I know this because I worked for a machine shop that made the toggles (the handle and spring assembly). Even a SPDT switch without center off the construction is basically the same. The only thing that changes is the see-saw contacts in the middle.

 

And small switches like that are made by both C&K and ALCO.

 

Here's a 2 button solution:

SW1 (mom) is a Momentary Push Button with Common wired to the motor (left)
SW2 (mom) is a Momentary Push Button with Common wired to the motor (right)
In Diagram A the dashed line indicates no rotation. The motor is dynamically locked (shorted)
In Diagram B the arched line indicates clockwise rotation (depending on how your motor is manufactured)
In Diagram C the arched line indicates COUNTER clockwise rotation
View attachment 342217
If both buttons are pressed at the same time the motor becomes dynamically locked.

Dynamic locking is when a permanent magnet DC motor leads are shorted together. The motor becomes a generator and the short circuit stalls the motor. It's called dynamic braking. Dynamic braking is usually done with resistors so that the motor isn't slammed with full current for that moment until the motor stops spinning.

And I'm going to ask it again: How are you using this? The motor only runs while you hold one button or the other. The moment you release a button the motor stops instantly (sort-a).

Hi again Tony..... What if no buttons are depressed in this configuration.... There will be no voltage send to the motor correct?

 

Hi again Tony..... What if no buttons are depressed in this configuration.... There will be no voltage send to the motor correct?

What Type Switches are these Tony? I know they are momentary but are they SPDT, DPDT, or SPST switches?
Joe

 

There will be no voltage send to the motor correct?

Correct. If NO buttons are pressed then NO voltage goes to the motor. If BOTH buttons are pressed at the same time there may be a potential voltage on the motor but there is no current to run the motor. In either case, both buttons pressed or not pressed the motor does not run at all. If it's a permanent magnet motor then both buttons pressed or not pressed results in the same thing - but makes it very difficult for the motor to be spun manually.

What Type Switches are these

SPDT.

 

Hi again Tony..... What if no buttons are depressed in this configuration.... There will be no voltage send to the motor correct?

They look like SPDT Switches... Is that correct?

 

Correct. If NO buttons are pressed then NO voltage goes to the motor. If BOTH buttons are pressed at the same time there may be a potential voltage on the motor but there is no current to run the motor. In either case, both buttons pressed or not pressed the motor does not run at all. If it's a permanent magnet motor then both buttons pressed or not pressed results in the same thing - but makes it very difficult for the motor to be spun manually.

SPDT.

Thanks Tony!! This looks like a great option for my application. I need to find some Micro Pushbutton Momentary SPDT Switches now! Joe

 

What Type Switches are these

SPDT.

They look like SPDT Switches... Is that correct?

Please refer to post #37, the final comment.