Circuit & Hardwares Controlling Rotating Directions of a DC Motor

Yes it can be done.

Use 2 push buttons each with 2 normally open contacts and 2 normally closed. The 2 normally closed are to prevent a short circuit if both buttons are pressed together.
For some reason I can't post drawings on this board otherwise I'd put one together for you.

Why do you keep swapping from one forum to the other, people try to help but you keep messing them around.

I'm still fascinated as to what this is going to do! But it's getting to the stage of throwing the towel in!

If you can't post drawings, there are at least two main reasons:

1: You are using Safari. CR4 has not succeeded in using Safari correctly; there is no toolbar, and therefore no camera icon to post images.

Use Firefox instead.

2: You don't have your drawings in an appropriate format. I haven't checked recently to see what else may be supported, but .JPG always works.

Export your drawings as .JPG images before submitting.

There are at least a couple of tutorials somewhere on CR4 to help...

The simplest way to do this is with a DPDT toggle switch.

Connect the motor to the center two contacts on the switch. Then connect the + wire from your DC supply to alternate points on both ends of the switch. Do the same with the - wire.

So... when the toggle switch is one way... the source is connected + and -, to the motor and then when you throw it the other way... the source is - and + and the motor reverses rotation.

It is a good and simple solution

But push button is easier to control and react faster to ON/OFF than that of DPDT.

The priciple is similar to a rolling / folding gate switch, but this case it will stop immediately when the finger release.

You can get a DPDT switch with spring return centre off. Have a look for one of those.

Might need a bigger switch if it plugs!!!!

If not intending to brake the motor before changing direction, better wait for it to stop or include this time before reversing!

Use H-bridge or two SPDT switches to change direction.

Is there a need to stop the motor before reversing the rotation direction ?

H Bridge has capability of run / free run / reverse run / inductive energy break capability. Extra breaking needs power clutch.

Could you please explain how H Bridge has inductive energy capability ?

Methinks he meant inductive energy braking.

My estimated power is only 25W.

I think I will switch different direction and no need to wait for it to stop.

One similar example is electric drill.

It depends on the size of the flywheel attached to it.

Ohh, that is simply stop power and let free run motor and not stop motor. It is not to stop motor. Break is short the motor coil to break by inductive back force.

Thanks for Professor Shyam!

If I add 2 low resistance resistors in H bridge circuit as diagram shown, I think it will avoid short-circuit happened even though the power of motor reduced a little bit.

By the way, which braking result is better in following combination:

1. S2 & S4 are closed?

2. S1 & S3 are closed?

S2 and S4 closed preferred as there is no current limit or S1 and S3 closed is breaking scheme. Energy stored in motor inductance is used against motion. Normally diodes put back this energy into power source. You have not shown four protection diodes.

Thanks for everybody!

I think a hoist push button can do this for switching.

Anyone has different opinion?

Looks expensive, but telemecanique usually is.

When are you going to tell us what the ultimate aim of this project is? it's lurched from one idea to another, but just doesn't seem to be getting anywhere.

May control a relay to control not only the device but also disable the supply of voltage from both sides simultaneously to make a short-circuit and also delay of connection to let the motor to stop before start in opposite side.

Quite so.

In this circuit diagram, if accidentially "on" both simutaneously, what is the worst thing happen and why.

Probably the worst is a major fire. Destroying your power source is another.

Take this and party like a rock star: