Phidgets Forums

Hey guys,

I've run into a bit of a wall and I'm hoping you can help me. Let me start off by saying I'm extremely new to all of this and I apologize in advance for any dumb questions I may ask, I'm trying to learn!

(Sorry, forum not letting me use img tags for some reason.)
http://i.imgur.com/I4bBovz.jpg

I was trying to control a permanent magnet latching solenoid with the 1012_2 board. I wired it up according to the user guide and it seemed to work correctly. I turned on the output and the plunger was pulled into the solenoid by the magnet.

(Sorry, forum not letting me use img tags for some reason.)
http://i.imgur.com/KkBGX9G.png

As far as I understood, to release the plunger from the pull of the permanent magnet, I have to give the solenoid a reverse polarity. It worked when I was doing it by hand with the DC power supply, but the problem is I had no idea how to do this with the board. I foolishly attempted it twice without coming here to ask and twice the board caught a bit of fire. I just put in another order for a new board, but I'm a little financially challenged at the moment so I was hoping one of you pros could help me out and show me how to wire this thing so I don't blow up another board. I will be eternally grateful.

If you didn't flip the diode around when you switched the wires, then the 1012 would be unhappy with the 18V short circuit running directly through the diode.

In order to switch forward and reverse polarity to a device, you'd want to build a circuit like an H-bridge. You'd also have to use two diodes, one for forward and one for reverse. They'd be placed right after one of the switches on either of the red paths in the diagram on the wiki page. Unfortunately, the 1012 has a switch-to-ground style of switch, so in order to build an H bridge you'd need a conventional switch like the ones on the 1017.