# 4 Motors Circuit Puzzle

#### jfran99

Joined Apr 21, 2021
30
I want to operate 4 dc motors clockwise, anticlockwise (i.e reverse polarity) and stationary (not moving). Operating each motor individually. And also be able to do the same to the 4 of them simultaneously (eg. move all anticlockwise at the same time). Does anyone have an idea of a circuit that could accomplish this?

#### djsfantasi

Joined Apr 11, 2010
7,700
What are you using to control each motors direction? Switches? MCU? Something else?

I think it could be done with five switches but I can’t provide a schematic at the moment (I’m waiting for my lunch at a restaurant). Anyway, it depends on how you answer my question...

Joined Jul 18, 2013
23,147
As per @djsfantasi , is the control purely manual, automatic or both?
Homework, so show what you have?

#### wayneh

Joined Sep 9, 2010
17,152
And also be able to do the same to the 4 of them simultaneously (eg. move all anticlockwise at the same time).
By this are you implying a sort of override of the individual settings, such that all 4 do the same thing regardless of the individual controls?

Otherwise, if you have independent control you can obviously make them all do the same thing by properly setting all 4 individual controls.

#### jfran99

Joined Apr 21, 2021
30
What are you using to control each motors direction? Switches? MCU? Something else?

I think it could be done with five switches but I can’t provide a schematic at the moment (I’m waiting for my lunch at a restaurant). Anyway, it depends on how you answer my question...
Hi, with switches

#### jfran99

Joined Apr 21, 2021
30
As per @djsfantasi , is the control purely manual, automatic or both?
Homework, so show what you have?
manual, ie. with switches

Joined Jul 18, 2013
23,147
The policy here is to assist with homework, not to actually give a complete answer.
IOW critique a present attempt.

#### djsfantasi

Joined Apr 11, 2010
7,700
So, what have you tried so far? As I said, it’s possible. But what have you done?

#### jfran99

Joined Apr 21, 2021
30
So, what have you tried so far? As I said, it’s possible. But what have you done?
I have tried a circuit with 5 switches (first image), which can operate 4 motors (individually and at the same time), but only in one direction (no reversed polarity). I´ve also tried to design a one with DPDT switches (to reverse polarity), but it´s difficult to activate all of them simultaneously this way (second image)

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#### djsfantasi

Joined Apr 11, 2010
7,700
You’re getting closer. Think about the single switch that controls them simultaneously. A SPST isn’t going to work.

#### MrAl

Joined Jun 17, 2014
8,259
If you need to control each motor individually think about using DPDT switches not SPST switches.
You should be able to find a very good solution.

#### jfran99

Joined Apr 21, 2021
30
You’re getting closer. Think about the single switch that controls them simultaneously. A SPST isn’t going to work.
I see, could it work like this?

Joined Jul 18, 2013
23,147
If sketching out circuits for this assignment or for future, if you intend going further, I suggest you not only learn and use the recognized symbols but proper diagram format also.
Whether ANSI or IEC.

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#### djsfantasi

Joined Apr 11, 2010
7,700
In particular the DPDT switches... if you use the proper symbols, you’ll see a major flaw in your last schematic.

What happens if the common switch is set for forward and one of the individual switches is set for reverse?

#### djsfantasi

Joined Apr 11, 2010
7,700
Another tip...

See if you can control one motor with two switches. Then we’ll add the other three motors.

Sometimes, breaking a problem down into easier problems is easier to find the final solution.

By the way, I foresee several other steps before you find an answer. The more you can do on your own, the quicker you’ll find the answer.

But first, try to solve the problem with just one motor.

#### jfran99

Joined Apr 21, 2021
30
Another tip...

See if you can control one motor with two switches. Then we’ll add the other three motors.

Sometimes, breaking a problem down into easier problems is easier to find the final solution.

By the way, I foresee several other steps before you find an answer. The more you can do on your own, the quicker you’ll find the answer.

But first, try to solve the problem with just one motor.
Okay, I´ll give it a go with one motor and two switches. Also, for the correct DPDT symbol, is it this one?

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#### djsfantasi

Joined Apr 11, 2010
7,700
BTW, MaxHeadRoom’s document doesn’t show a DPDT switch clearly enough for me. So I drew this picture for you...

UPDATE: You were posting while I was. Your picture is correct, as you can see by comparing it to mine.

#### jfran99

Joined Apr 21, 2021
30
For 1 motor it would work like this right?

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#### djsfantasi

Joined Apr 11, 2010
7,700
For 1 motor it would work like this right?
Where’s the second switch? The control which overrides the individual switch position... and provides another way of changing the motors direction?

BTW, I redrew your schematic so to me the reversing operation is clearer.

By the way, there is an obvious answer that I’m hoping you get...

It’s wrong, but it’s a step in the right direction and will lead you to the final, correct solution. Don’t give up, you’re making good progress.

Just don’t forget the second switch.

#### jfran99

Joined Apr 21, 2021
30
Where’s the second switch? The control which overrides the individual switch position... and provides another way of changing the motors direction?

BTW, I redrew your schematic so to me the reversing operation is clearer.
View attachment 236320

By the way, there is an obvious answer that I’m hoping you get...

It’s wrong, but it’s a step in the right direction and will lead you to the final, correct solution. Don’t give up, you’re making good progress.

Just don’t forget the second switch.
Hmm, I got the following circuit, but not sure if it would work if one switch is set direct and the other on reverse

Thanks for the motivation btw!! And for your help

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