Hello,
I'm more or less a newbie to electronics design and could use a little help with a project I'm working on. The project is a programmable logic controlled clutch system for a drag bike. I'm using a Galil RIO PLC controller and as an experienced software guy I'm OK with programming the controller. Where I need a little help is getting the output of the controller to do what I need it to do in the real world.
Essentially, I've got a 12v solenoid that can block or release hydraulic fluid. The solenoid has about 7.8 ohms resistance so I figure that at 14v it will take somewhere around 1.8 amps of current to activate it. The logic controller has either 12-24v 500mA sourcing digital outputs or 5-24v 25mA sinking outputs. I'm guessing that the sinking output would be better to use because I don't have to power the power transistors from the controller that way.
So the deal is that I need to put together the stuff between the solenoid and the PL controller. From what I understand a MOSFET transistor is the way to go. I'm afraid that I don't really know where to start on trying to identify the appropriate part. I don't know if I can just get a transistor, hook it up to the controller or if I need something more complicated, such as a triggering transistor that would then turn on the power transistor. I guess that I also need to be concerned about the current back flowing when the power to the solenoid is turned off and the magnetic field collapses.
Can anyone give me some pointers to get me started in the right direction on this project?
Thanks,
Eric
I'm more or less a newbie to electronics design and could use a little help with a project I'm working on. The project is a programmable logic controlled clutch system for a drag bike. I'm using a Galil RIO PLC controller and as an experienced software guy I'm OK with programming the controller. Where I need a little help is getting the output of the controller to do what I need it to do in the real world.
Essentially, I've got a 12v solenoid that can block or release hydraulic fluid. The solenoid has about 7.8 ohms resistance so I figure that at 14v it will take somewhere around 1.8 amps of current to activate it. The logic controller has either 12-24v 500mA sourcing digital outputs or 5-24v 25mA sinking outputs. I'm guessing that the sinking output would be better to use because I don't have to power the power transistors from the controller that way.
So the deal is that I need to put together the stuff between the solenoid and the PL controller. From what I understand a MOSFET transistor is the way to go. I'm afraid that I don't really know where to start on trying to identify the appropriate part. I don't know if I can just get a transistor, hook it up to the controller or if I need something more complicated, such as a triggering transistor that would then turn on the power transistor. I guess that I also need to be concerned about the current back flowing when the power to the solenoid is turned off and the magnetic field collapses.
Can anyone give me some pointers to get me started in the right direction on this project?
Thanks,
Eric