Where to start: Valve/Solenoid Control

Mech_E_Travis

Ok·Guys, I am a Mechanical Engineer, and I am looking to build a Solenoid valve driven airsoft rifle...but I need a controller that I can adjust valve dwell, close (after trigger is pulled, hold open x seconds) and possibly go full auto. I am entirely ignorant of anything but basic circuits as far as solid state components go. I know that I need a controller, a valve, and a valve driver board. Valve selection seems pretty straightforward, but I need some sort of "relay" type board to isolate the valve (large amp draw) from the controller (small amp draw). My main question is not "how do I do this" because I want to figure it out but: where do I go to get started in learning about such topics? Is this situation a Stamp suitable one, or is a dedicated board more suited to this application? Lastly, any suggestions?
Thanks!
Travis

Chris Savage

Travis,
·
·· You’re in luck!· It’s fairly easy to interface a solenoid to a BASIC Stamp.· The main thing you need to know is the voltage and current draw of the solenoid.· Two BASIC circuits are attached.· The MOSFET circuit is pretty straight forward and uses a common MOSFET, the IRL520, which can handle a little over 9A.· The transistor circuit is similar and requires an NPN circuit.· The transistor you use will depend on the voltage and current.· Choose R1 based on several factors, including current required to bias the transistor.· I hope this helps.· Take care.


NOTE: While the schematics show a Relay, a solenoid is electrically equivalent as far as the coil goes.

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Chris Savage
Parallax Tech Support