Wiring A Reversible Motor

[airman00]

How can I wire a reversible motor without shorting out the battery. If I wire it up with only one switch per direction( two switches in total), there ends up being a short circuit.
To overcome this I use DPDT relays and switched the positive and negative current each time. My only problem is that the relays take too long to switch and sometimes don't remain closed all the way.
Please tell me what to do. Whats a motor driver???Please explain.
,Eric

[Steve Joblin]

what you need is a circuit called an "H-Bridge" (so named because the schematic of the components when drawn, usually resembles the letter "H".

Dallas Personal Robots Group (DRPG) has a decent overview... http://www.dprg.org/tutorials/1998-04a/

[suren]

A motor driver is for driving the motors in any direction you want,to vary the speed .
For a DC motor u can use L293D motor driver.if you have any other motor do let me know.

[Steve Joblin]

The L293D is basically an H-Bridge circuit built into a single DIP chip.  The problem is that the only way to control motor speed with a L293D is to feed it a PWM signal.  A 555 circuit or a microcontroller can produce a PWM signal. 

[airman00]

Im gonna use the driver found here. Its the L298 Motor Driver
http://www.robotobjects.com/scripts/prodView.asp?idproduct=67

Thank You for your help

[frank26080115]

Toshiba TA8050P
30V, 1.5A, internal dioded,7 SIP heatsinked goodness for 0.56 cents each.

Look for them on ebay, very nice seller, negotiate for discount.

[Brandon121233]

you can get that H-Bridge as a free sample from STMicroelectronics

[Admin]

I dont recommend home made H-bridges, too much work.

Before buying your motor driver, make sure you know the voltage and current that your motor needs.