I'm having a bit of a run of bad luck with circuits. I'm trying to get the attached solenoid valve circuit to work with Axon. I'm using a regulated 5V supply pin and correlating ground from one of Axon's analog pins for the circuit ground and +5V supply. Then I'm using one of Axon's digital pins that I've turned on as an input to toggle the solenoid valve on and off.
The NPN transistor I am using is a 2N5210 (http://www.fairchildsemi.com/ds/2N/2N5210.pdf
). To be honest I'm new to NPN transistors and am not sure this is the right one I need for this circuit.
The purpose of the circuit is when the Axon digital I/O pin goes digital high, then the NPN switches to ground and turns on the solenoid valve.
I can get the solenoid valve to turn on and off by connecting it straight to the 5V supply and ground from Axon and toggling it on and off with a physical flip switch but the problem I'm having is that the NPN isn't creating a true ground. My multimeter is telling me that when the Axon I/O goes high, the NPN for some reason goes to 2.81V instead of ground.
Is this the right NPN for this application? If anyone has any other ways to be able to switch the valve on and off with the Axon please feel free to share.
The solenoid valve I'm using has the following specs
Voltage: 5 VDC
Amps: 320 mA
Resistance: 18 Ohm