Just set up the 'fading' circuit with a 9v battery and it worked great!
But will all the components be safe with a 12v supply going through it? I know the LEDs i bought are 9-12v so im fairly sure they will be fine.
Also, the 'fading' is a little fast, i read in the adobe file that it is the resistor between pins 3 and 6 to ground that i should change to adjust it. But do i need a stronger or weaker resistor to make it go slower?
Howdy again! Actually, what it says is that changing that resistor will affect how dim the LEDs get before they go out. Is that what you mean? If you just want to adjust the rate at which they fade up and down, adjust the value of the 47k resistor between pins 2 and 7. Make it higher for slower and lower for faster. Even better, stick a 100k or so linear potentiometer in there with one leg to pin 2 and the wiper to pin 7.
All the components in the circuit will be fine with 12V, but remember that a 12V wall wart will give a no-load reading voltage of well over 12V. I mean, if you just plug the wall wart into the socket and measure its output when it's not powering anything, you'll get a reading of maybe 14 or 15V instead of 12V. The idea is that since they are unregulated, they "sag" the voltage when something draws a certain load through them. Say the adaptor is rated 12V @ 500mA--that means that it's expected to put out around 12V when some device is drawing 500mA through it. If the device pulls less, then the voltage will be higher.
Sounds weird, but it's true.
The point behind all this rambling is that the 12VAC adaptor is going to give you more than 12VDC after rectification and filtering already, and if the adaptor has a high amp rating, you could wind up with more than 15V going into your circuit. I don't think you will exceed the 1458's max supply voltage or max input voltages, although I haven't really crunched all the numbers.
What I'm saying is: I *think* you should be fine, but if it were me, I'd just try it (after making sure I had anyother 1458 on hand in case I was wrong).
Again, I hope somebody will correct me if I'm leading you down the garden path here.
Good luck!
Torben