I have a project that I would like to use two small push button style switches, to control the direction of a dc motor.

The details are a 12 volt DC battery (lawn mower battery), power window motor, not sure on any specs for this motor.

I do NOT (and can't) use one switch (DPDT). Is there a way to wire this so that two switches can be used, one will make the motor spin forward and the other will make the motor spin in reverse. I don't know if a relay needs to be used, as to protect the circuit from both switches being pressed at the same time by accident. They need to be momentary switches, so when the push button is pressed the motor spins then stops after being released.

Can somebody provide a list of items needed (switch types SPST, SPDT, RELAYS, ETC.) and a diagram to wire them. THANK YOU!

 

I'll look up a diagram that I drew for another project.

You just need the two switches if they are rugged enough.

No interlock needed. If both are pressed motor is off.

 

Couldn't find an exact match.
Here's one.............

 

I did find one with bosch relay numbering if switches are light duty.

 

Thanks for your quick help. I don't know much about this stuff so the diagram is a bit greek to me. Any idea where I can get parts (online) just need two small push button switches and whatever else to make the diagram work?

 

use the second diagram with the relays or make darn sure your switches are rated for the motors current.

 

This one may work for a few hundred operations. 5Amp DC

http://www.ebay.com/itm/2-Pcs-3A-25...953?pt=LH_DefaultDomain_0&hash=item35c3f23c49

For long life use relays.

Diagram shows connection.
Common switch terminal of each switch, to motor.

Pos. and neg. of battery, to other two switch terminals.

 

You need:
1) Two pushbutton switches, SPST, N.O.
2) Two relays, SPDT. Automotive relays that are SPDT will work fine, are inexpensive, and available everywhere. You can connect to them using 1/4" spade connectors.

Not shown are reverse-EMF diodes across the relay coils, and from the motor terminals to +V and -V; without the diodes across the relay coils, the pushbutton contacts will get burned, without the motor diodes, the relay contacts will get burned. Perhaps inwo will add them to the schematic drawing for you.

We don't know where in the world you are, so it's difficult to suggest where you might find the parts you need.

 

Cap and diodes are not necessary for operation. Only for long contact life.
Often have internal suppression from 85-86.

 

One thing to keep in mind if the motor carries a fairly high load and the inertia is high, then instant reversal before the motor has come to a stop will result in very high motor current.
And with shorted armature braking in effect, very high BEMF current.
Max.

 

I purchased the components needed, two spst n.o. push button switches and two spdt relays, with the numbers shown (87 87a 30 85 86). Is it possible to get a more laymen's diagram to wire this application up. I know the diagram provided should / will work but I don't really understand it to well, this is not my expertise. Thanks in advance.

 

Try this scribble...............................................................................................

 

that is perfect, excatly what I was looking for. Thanks for your awesome help. will let you know how it works

 

I received email notifications of questions asked about this thread today so I answered them. Now the questions are gone.
I receive other email notifications of activity on other old threads too, then the questions are also deleted by somebody after I answer.

 

A moderator probably split the thread and the changes haven't shown up yet.

 

It was a resurrected thread.
Max.

 

I'm building the same thing - but planning on using a DPDT momentary switch. It's a 12V 6A motor, would I have to worry about inductive kickback?

 

I'm building the same thing - but planning on using a DPDT momentary switch. It's a 12V 6A motor, would I have to worry about inductive kickback?

Yes.

 

Yes.

Thank you. Any words of advice? I've been struggling to find a solution for a week now - but I'm new to EE. I can't figure out how to place a diode that is directional for this situation.

 

I was thinking this might work.