Hello everyone,

I'm working on a project involving these actuators:

I need something to reverse their motion. Can I just use an H-bridge, or do you recommend using a motor shield for it instead, like the Monster Motor Shield on SparkFun? Also, how can I figure out whether it will conflict with the USB shield that I'm using?

They tell you to use a 12 volts 10 Ampere power supply. You can't control that with a L298. I don't think they will actually draw 10 A all the time but it's better to be safe than sorry. So yes, a 30 Ampere monster moto shield will do for sure, but it is a bit costly.

Making your own bridge can be an interesting experience, but in the end that will cost you more than those 80 bucks.

Inexpensive high power H-bridge.

That would be a better choice, provided the specifications are correct. Read the comments at the sparkfun site about the monster moto shield.

That e-bay link is typical advertisement. I'd like to be there to see how long it would do 43 Amps without any larger heat sink than the PCB. Let's see ... if it can saturate to 1V on, that's 43 watts. Maybe for 1 sec., not much longer.

It looks like the heatsink covers the entire back of the board.

A shame they are using the Arduino name and logo on their product when it's clearly not an Arduino product.

For simple forward/reverse control [u]without[/u] PWM speed control one can wire two SPDT relays as an H bridge. That arrangement will also short the motor terminals when both relays are OFF or both are ON, so it will brake the actuator motor improving static load handling. If you don't want the braking you can use an SPST to turn power on and off and a DPDT to reverse direction. You would need a driver transistor (or MOSFET) between the Arduino and the relays. Ciao, Lenny