switching polarity for a solenoid

Hi all, I'm new to electronics, so this may be a silly question... I have 4 9v solenoids that I want to drive independently of each other. To do this I need to be able to reverse the polarity to the solenoids to get them to toggle in one direction or the other (they don't return when unpowered). I asked the best way to achieve this on a different forum and someone suggested I look at an "H-Bridge". I've looked and found L293D or SN754410. Both of these sound like they can drive 2 solenoids, so I'd need 2 of them to drive 4 solenoids. Is this the best approach, or does anyone else have any better / cheaper / easier suggestions? Also, the Logic voltage seems to be 5v. How would I wire this up to the Netduino? thanks Tim

Hi all,

I'm new to electronics, so this may be a silly question...

I have 4 9v solenoids that I want to drive independently of each other. To do this I need to be able to reverse the polarity to the solenoids to get them to toggle in one direction or the other (they don't return when unpowered). I asked the best way to achieve this on a different forum and someone suggested I look at an "H-Bridge". I've looked and found L293D or SN754410. Both of these sound like they can drive 2 solenoids, so I'd need 2 of them to drive 4 solenoids.

Is this the best approach, or does anyone else have any better / cheaper / easier suggestions?

Also, the Logic voltage seems to be 5v. How would I wire this up to the Netduino?

thanks
Tim

Unless I'm reading the spec sheet wrong, it can handle 2 to 5.5v on the logic side, which means the Netduino can safely drive the SN754410 with out the need for additional components.

I found this DC motor control with an H-Bridge tutorial you might be interested in. They use an Arduino, but you can do it with the Netduino just fine.

-dan

Unless I'm reading the spec sheet wrong, it can handle 2 to 5.5v on the logic side, which means the Netduino can safely drive the SN754410 with out the need for additional components.

Hi Dan,

thanks for the link.

The reason I was asking about driving 5v from netduino was because on the hardware details page:
http://www.netduino....duino/specs.htm

it says this:
digital i/o are 3.3 V--but 5 V tolerant

to me that says the digital outputs will push out 3.3v but the inputs can take up to 5v. Am I wrong? Do I need to do anything to get the outputs to push out 5v?

thanks
Tim

Tim, why do you need pushing the N's outputs to +5V? I agree with Dan: the specs say it is Netduino compatible. Cheers

Tim, why do you need pushing the N's outputs to +5V?
I agree with Dan: the specs say it is Netduino compatible.
Cheers

Hi Mario,

like I say, I'm a newbie, so I'm probably missing something. I was just worried that the Netduino wouldn't have enough voltage to drive the logic side of the H-Bridge. You guys seem to think there won't be a problem, so I've placed an order and will give it a go.

thanks to both of you for your advice

Tim