2 speed DC motor switch wiring needed

Thread Starter

liteace

Joined Mar 7, 2012
162
Hi All, I have here a 12v, 2 speed DC motor, it has 3 wires,

red = fast,
green = slow,
black = earth

what I would like if poss is 2 ON/Off/ON 3 position switches, 1 switch to switch low high speed, the other switch to switch the motor forward / reverse.
can this be done, I dont mind adding a relay or 2 if needed.
I know theres controllers out there that can do this but need to keep it simple

would this work, sorry about the drawing
Thanks

Capture_1.JPG
 
Last edited:

MisterBill2

Joined Jan 23, 2018
13,805
Short answer: YES, the circuit shown will work. Also, that drawing is better than many of them I see here, so no need to apologie for it.
Of course, the ability to reverse depends on it being a permanent magnet DC motor. If it is a wound field motor reversing the polarity will not have much effect.
 

Thread Starter

liteace

Joined Mar 7, 2012
162
Im 99% sure its a permanent magnet as testing with battery, when reversing the polarity the motor spins the other way
 

Tonyr1084

Joined Sep 24, 2015
7,199
One DPDT switch with center off and the one reversing switch will do. An alternative would be a DPDT switch (NOT center off) and the other switch (SPDT) with center off will achieve the same thing. The SPDT switch is for reversing. Having center off means you can switch direction by first switching it off, letting it come to a stop, then switching it to reverse. You don't want to switch from forward to reverse without first letting the motor stop spinning. Doing so is very hard on the motor and will drastically shorten the lifespan of the motor.

See edit below
 
Last edited:

MisterBill2

Joined Jan 23, 2018
13,805
One DPDT switch with center off and the one reversing switch will do. An alternative would be a DPDT switch (NOT center off) and the other switch (SPDT) with center off will achieve the same thing. The SPDT switch is for reversing. Having center off means you can switch direction by first switching it off, letting it come to a stop, then switching it to reverse. You don't want to switch from forward to reverse without first letting the motor stop spinning. Doing so is very hard on the motor and will drastically shorten the lifespan of the motor.
I think that Tony got the switch applications reversed, and needs to edit. The SPDT switch would select the speed while the DPDT switch will do the reversing.
 

Tonyr1084

Joined Sep 24, 2015
7,199
MisterBill2 is right. I got that backwards. Or befuddled, or something.

Here's my edit to post # 4
One DPDT switch with Center Off for reversing. One SPDT switch for speed control. Sorry for the confusion. I still stand by my statement that you need to let the motor stop spinning before you reverse it. You may want to consider some sort of delay circuitry that will prevent accidental reversing before the full speed motor fully stops.
 

Tonyr1084

Joined Sep 24, 2015
7,199
Two drawings: Left drawing shows toggle switches. The DPDT switch with Center Off will have six terminals. Typically pins 2 & 5 are the common pins but pin 2 & pin 5 are isolated from each other. When the toggle is in one side or the other it selects the motor direction. The SPDT switch is to control the speed. Again, thanks MisterBill2 for pointing out my mistake. It's appreciated when others spot mistakes and brings them to the fore. That way another user doesn't make the same mistake.

The right drawing shows the schematic version, which is how us electronics guys normally think. Your drawing was good. This drawing is just to clarify what I mean by my sort-a pictograph.
1669047795623.png1669048763726.png
 

Thread Starter

liteace

Joined Mar 7, 2012
162
Thanks for the input guys, I see your schematic is slightly different from my drawing, Ive wired +12 feed to center pins 2 and 4, then load is on 1, 5, 2 & 6, would does this make any difference?
 

Reloadron

Joined Jan 15, 2015
7,084
Just if needed consider something. Switching a motor between Fwd and Rev less a pause can have some not real good results. This is where your Fwd / Rev switch you may want a center off. This depends on motor and if reduction gears are involved. Just a consideration depending on motor. :)

Ron
 

MisterBill2

Joined Jan 23, 2018
13,805
Just if needed consider something. Switching a motor between Fwd and Rev less a pause can have some not real good results. This is where your Fwd / Rev switch you may want a center off. This depends on motor and if reduction gears are involved. Just a consideration depending on motor. :)

Ron
Back in post #1 the TS did request verification of the design with a center off switch. The drawing did not show it but the description included it. So evidently the TS understands.
AND the drawing was one of the better freehand ones presented in the past year.
 
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