Thread: reversing dc motor w relay

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Can anybody point me to or explain how to wire a relay to switch polarity on a dc motor. 12v relay and motor, guilder control. Thanks In advance. Lester

You need at least a double pole relay so you can switch both the positive and negative lines with one relay. Your common output poles on the relay will go to your motor, and then wire the Normally Closed (NC) pole on one to positive and the NC pole on the other to negative. Then wire the Normally open (NO) pole on the firs tto negative and the NO pole on the other to positive.

-EEric

so I run four wires to the motor... two each terminal?

Lester you might want to consider something like this motor controller from Hobby Engineering which is a simple kit and allows you to switch motor directions on fly. You don't say how much current your motor draws but this controller can handle a few amps.

No just two to the motor from the center two poles of the switch and two to the switch, but you attach the negative to two poles kitty corner to each other and the same with the positive wire

Monster guts has a wiper motor controller that has a polarity switch on it.

heres how to make a reversing motor using relays

Excel Control

Here is a schematic of how the relay should be hooked up:

Motor Reverse picture by bradbaum - Photobucket

Take a look at this thread.

I added some arrows to my drawing to show how the current flows when the relay is energized or not:

Forward Motor picture by bradbaum - Photobucket

Reverse Motor picture by bradbaum - Photobucket

Hope this helps.