48V DC motor relay or driver

[hosa200]

Hello Every Body,

I have 48VDC motor (3A at load) ,I give it 48VDC from 4*12VDC batteries ,but i want to control it direction ,So I have tried relays but it burned out .

Can anyone help me to make a motor driver can handle 48VDC and 7A (for safe) to control motor direction and speed ??

Thanks alot

[jwatte]

So I have tried relays but it burned out

There exists relays/contactors that support > 7A loads and > 48V voltage. Try a better relay?

[hosa200]

There exists relays/contactors that support > 7A loads and > 48V voltage. Try a better relay?

i can't find a relay has more than 30VDC Maximum switching voltage

[jwatte]

Power relays that do over 48VDC, up to 1000VDC, and 10+ A:
http://goo.gl/BtWbnP

Seems like $1.37 will get you there at 10A:
http://www.digikey.com/product-detail/en/G5LE-14%20DC12/Z1012-ND/280369
For a 16A current rating, you have to pay almost $3:
http://www.digikey.com/product-detail/en/G2RL-1A-E%20DC24/Z2845-ND/368854

That being said, do you want speed control? If so, I'd suggest a MOSFET based motor controller. You'd probably have to go industrial-grade to power 48V motors, so expect to pay a few hundred in that case, and get ruggedized drivers.

[hosa200]

That being said, do you want speed control? If so, I'd suggest a MOSFET based motor controller. You'd probably have to go industrial-grade to power 48V motors, so expect to pay a few hundred in that case, and get ruggedized drivers.

thanks a lot,
about speed control ,i want to learn how to make my own driver

[jwatte]

To make your own driver, you need four high-current high-voltage MOSFET transistors like the IRF530N, and two half-bridge drivers like the IRS2003. (Note: at least 100V GD rating for your application)
Then you need a PCB and connectors that can handle the current (which at 7A isn't a problem with 100 mil traces and 1oz copper -- if you can go 2 oz, so much the better!)
You also need a regulator that generates a 10-18V control voltage. 12V would be fine, and easy to make. Add a fast diode and a couple of 35V rated 100 nF ceramic capacitors per driver side, and you're done!

[hosa200]

To make your own driver, you need four high-current high-voltage MOSFET transistors like the IRF530N, and two half-bridge drivers like the IRS2003. (Note: at least 100V GD rating for your application)
Then you need a PCB and connectors that can handle the current (which at 7A isn't a problem with 100 mil traces and 1oz copper -- if you can go 2 oz, so much the better!)
You also need a regulator that generates a 10-18V control voltage. 12V would be fine, and easy to make. Add a fast diode and a couple of 35V rated 100 nF ceramic capacitors per driver side, and you're done!

Thank you,I'll try this.