Thread: 24 volt questions

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Hello , First off I'm terrible at explaining things ,so just giving fair warning.
I am trying to power a motor that can spin either direction, depending on the polarity. Now my idea is to connect two 24volt transformers to this motor,and if I want it to spin one way turn on one transformer. Now if i want it to spin the other way turn on the other. My question is, will it harm the transformer if electricity from the other transformer feeds back into the outputs of the other transformer?
Thanks for any input .

If this is 24VDC then just use one transformer with a Double Pole, Single Throw (DPST) switch to reverse the positive and negative leads to the motor.

If you use a 24VDC motor on 24VAC(what you would get from a transformer) it would just sit there and vibrate at 60 HZ. You would have to have a rectification circuit of some type to keep the power positive. A normal AC wave swings positive and negative during a full cycle.
You would be able to use the double throw/double pole relay in an h-bridge configuration if the 24 volts was DC.
I would suggest using batteries or a DC power supply for this application. A laptop power supply might work just fine and you can get those pretty cheap at an electronics surplus store.

What your looking for is something called an H bridge.

This is what andisnw suggested, and is the easiest way to do what you want. You can use 2 DPST relays, Or a single DPDT relay!
http://www.teamonslaught.fsnet.co.uk/DPST.gif

And as toymaker said, hopefully the motors are AC motors, yes?

This is what the motor says on the side of it. 24V 3.9 amp max.
I'm pretty sure that it's DC . I'm going to be operating this motor with light o rama. Is their a type of polarity switch that can reverse polarity using 110vac

If your sure its a DC motor it will not work at all with AC, which is what it will be getting if your just using a transformer plugged into the wall.

Your going to need a 24VDC power supply first.
Digi-Key - 285-1806-ND (Manufacturer - LS100-24)
Might be acceptable...

And then you can get a 110VAC relay to control the polarity stuff with light-o-rama.
Digi-Key - PB1146-ND (Manufacturer - PT22A615B)

I'm sure you know this but this stuff could be potentially dangerous, and lethal, if done incorrectly. Just giving fair warning!

Sorry by transformer I meant power supply

Ok super then. All you'll need is one of those relays I linked. Ill draw you up a diagram on how to safely hook it up if you need.

Now on that relay you linked, can you explain how it works?
How I'm thinking that it works is, That when the relay is off polarity is one direction, and that when power to the relay is on the polarity is reversed.
Am I right in my thinking?
thanks

Yes you are correct.

For that specific relay you want to:

Connect Pins 13 and 14 (the relay coil) to a channel on you rlight o rama system. 13 for neutral and 14 for the HOT. That channel will control the direction, when its on it will go forward, when off reverse.

Now connect pins 10 and 11 to your motor. 10 to positive lead, 11 to the negative.

Now connect pins 2 and 7 to the positive 24VDC of your power supply.

Now connect pins 3 and 6 to the negative of your power supply.

And that should do it! Be safe!

Ghetto schematic attached.