I made this circuit to control a 24V Solenoid.
I'm using a 22.5V power supply to power the solenoid, and a 12V power supply to power the arduino. I'm pretty rusty and am having a hard time figuring out if I can use only 1 power supply, and how I would wire that up. Can I use the 22.5V PS? Do I need a new one? Yikes I just don't know. Any advice is much appreciated. thanks!
You can use one power supply to power everything, but you would need to use a SMPS to get the 22.5 down to 5volts for the Arduino.
Something like this: eBay
Well you can't power the UNO with 22.5VDC, and it's a 24V solenoid, but your 22.5V power supply can only provide a maximum of 85mA, most likely not enough for both the UNO and the solenoid. If it did supply enough current, you could use a (switching) regulator to drop the 22.5V to 7-9VDC for the UNO Vin, or even 5V for direct connection to the UNO 5V rail, as Larry says.
Before anything else, though, what is the current draw of your solenoid?
Edit: Oh, and I guess you meant "1K resistor" on that horrible Frizing diagram, not "1K transistor".
(I don't mean that your Frizing diagram is especially horrible - ALL Fritzing diagrams are horrible.)
Good lateral thinking. Probably the best option in this case, since the 12V supply can go to 1A max.
Unless it's a fairly 'current-hungry' solenoid. Knowing it's current consumption or resistance would be handy.
Oh shoot I did mean RESISTOR.
I don't have an ammeter anymore so I cant test the solenoid but the label does say 96Ohms. Please note that I'm a big dumb idiot.
Ohms law, (I=V/R), tells me that the solenoid draws 234mA at 22.5VDC, (250mA at 24VDC) - too much for your 22.5VDC 85mA power supply.
You're best off going with Larry's idea - a DC-DC converter to step the 12VDC supply up to 24VDC for the solenoid. Even then, make sure you put a decent reservoir capacitor across the DC-DC converter input pins. Something like a 1000uF 25V electrolytic capacitor would be good, but a bit smaller would suffice.
Edit: I just noticed that Larry already pointed this out.