I'm trying to use an Arduino+transistor to control a shutter (which I believe is a solenoid) at work. The shutter is normally connected to a power supply by two small wires (positive and negative) and from what I've gathered with my DMM an 11.3 V 3.8 mA current is applied to the shutter to keep it closed, and when it is opened the voltage and current drop to 0 before reapplying the current to close it again.
Right now I have the following circuit configured so that the transistor base is connected to the PMW 9 pin on the arduino, which cycles between 5 seconds of output = HIGH (5V) and output = LOW (0V). What confuses me the most is that when I take measurements with my DMM I get roughly the same results (12V and 4mA) on the solenoid but the shutter doesn't close.
Any thoughts? Is there something I'm missing in my circuit? The only thing I can think of is that maybe the current isn't ramping up fast enough to induce a noticeable magnetic force (I think that's how it works, don't judge me I haven't taken emag in a while), but I don't know how I'd be able to combat this. Thanks.
If my circuit isn't clear enough (mostly in the arduino area) leave a comment and I'll try to clear things up.
EDIT: I realize now that the arduino is actually sending a pulse-width modulated signal with duty cycle of 100%. Could this be causing problems?
EDIT2: Updated the schematic.