Go Down

Topic: Powering 1/2hp dc motor (Read 1 time) previous topic - next topic

uler3161

I have a 1/2 hp 12vdc motor on a piece of equipment. I don't have the motor specs in front of me, but a web search suggests it is a 1700 rpm motor that uses between 10 and 60 amps.

Currently it has speed control in one direction, but a set speed in the other. I want to be able to replicate this ability and power the direction and speed from my Arduino if possible. I might even want to control speed in both directions. I may also look into updating to a 3/4hp motor at some point (10 to 75A), so I'd like to get a controller I could still use with that.

I'm pretty new to electronics, but I'm guessing I need some kind of H-bridge for this? All the ones I find seem to be for smaller motors. Is there something out there that someone can point me to? I'd be willing to build an H-bridge if I can get a good grasp on what components I need. Thanks.


Erdin

You need a full H-bridge.
You could build a H-bridge with power mosfets.
But also a number of mosfet H-bridge modules can handle that current.
You might have to figure out yourself how to connect them.

This one is too expensive, http://www.robotpower.com/products/osmc_info.html
And I can't find others right now.

AWOL

Quote
10 and 60 amps.

60 amps at 12V is more like 1hp. (1hp = 740W)
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

uler3161


Quote
10 and 60 amps.

60 amps at 12V is more like 1hp. (1hp = 740W)


Thanks. The amperage values were what someone posted on a forum somewhere. 60A would be equivalent of running a 1/2hp on 6V wouldn't it? I know the existing motor controller has a 12V input, but maybe it's actually only allowing up to 6V to the motor.

afremont

My guess is the 60A is the locked rotor current + inrush current.
Experience, it's what you get when you were expecting something else.

uler3161

I found http://hades.mech.northwestern.edu/index.php/Driving_a_high_current_DC_Motor_using_an_H-bridge. Since my input is 12V, could I simply lose the dc-dc converter and be ok?

Assuming this circuit would be ok, how would I be controlling it on a arduino? It sounds like to be stationary, I need to write a value of 127 to it? Closer I get to 255 would mean faster in one direction, while closer to 0 would mean faster in the other direction?

Chagrin

Wouldn't it be a lot simpler just to throw in a DPDT switch so you can reverse the leads on the motor?

wizdum


Wouldn't it be a lot simpler just to throw in a DPDT switch so you can reverse the leads on the motor?


Or even something like this with DPDT relays:
http://www.homebuiltrovs.com/howtorelays.html

Thats a lot of current, I doubt there is a cheap solution using MOSFET H-Bridges.

EDIT: Scratch that, didn't notice the speed control requirement.
"Anyone who isn't confused really doesn't understand the situation."

Electronic props for Airsoft, paintball, and laser tag -> www.nightscapetech.com

uler3161


Wouldn't it be a lot simpler just to throw in a DPDT switch so you can reverse the leads on the motor?


I do think it should be simpler to reverse the leads like that. I'm guessing the schematic I posted is done that way so that only one wire is used to control both direction and speed? Or am I just reading it wrong?

Chagrin

My point was that you already have variable speed in one direction. If you use a DPDT switch on the motor leads to reverse them then you can use the same variable speed to go in the other direction.

Go Up
 


Please enter a valid email to subscribe

Confirm your email address

We need to confirm your email address.
To complete the subscription, please click the link in the email we just sent you.

Thank you for subscribing!

Arduino
via Egeo 16
Torino, 10131
Italy