I've created a working prototype of a circuit to open and close a solenoid based on microcontroller output, and now I'm trying to scale it up to run 6 solenoids instead of 1 (only 1 solenoid will be running at a time). The original circuit and my new one are attached. Can somebody take a look at the scaled-up version and make sure it won't burn down my house? Only 3 solenoids are pictured, but you can guess how I'm going to expand it from there. Also, if there's a more efficient way to build the schematic, I'd love to hear it.
Edit: Just checked out the darlington array you suggested. That looks pretty awesome (and would simplify my design a lot). I'll update my schematic and post again (for paranoia).
Another (slightly related) question. What's the simplest way to make this into a permanent device? Right now I'm working on a breadboard, but I think I'd rather build it properly than mount it to my machine on a breadboard.
Edit: Just checked out the darlington array you suggested. That looks pretty awesome (and would simplify my design a lot). I'll update my schematic and post again (for paranoia).
Another (slightly related) question. What's the simplest way to make this into a permanent device? Right now I'm working on a breadboard, but I think I'd rather build it properly than mount it to my machine on a breadboard.
I thought I better mention it, in case he later on decided to switch on more solenoids, but if limits it to just a couple at any time, it should just be OK.
The ULN replaces EVERYTHING?? If I'm reading that right, I'm just going to wire the output from the arduino to 1, gnd to 9, and the solenoid and 12v to 18 and 10? The ULN has the resistors and all embedded in it?
The ULN replaces EVERYTHING?? If I'm reading that right, I'm just going to wire the output from the arduino to 1, gnd to 9, and the solenoid and 12v to 18 and 10? The ULN has the resistors and all embedded in it?
Pins 18,17,16,15,14,13, goto the bottom of the solenoid coils, and +12V to the top of the solenoids.
pins 1,2,3,4,5,6 goto the MCU
pin 10 goes to +12V supply
pin 9 to 0V of the 12V supply and the 0V of the MCU.