Creating button to fire & POWER the cameras

[jakegaisser]

I do not have a usb hub. but I do have a pile of old motherboards that were headed to the trash after I salvaged capacitors from them. all that is required is to send a 3-5 volt pulse to the cameras right?

couldn't I cut the USB header off the back of one of these motherboards and solder wires from two of the usb ports and just use a momentary switch to short the positive side with the AA batteries positive.

I will have to draw up a diagram of my plan... I actually think I might have some of those USB headers that you put into the expansion slot of a computer case... I think this would work as well...

[jakegaisser]

so far i've found this post: http://diybookscanner.org/forum/viewtop ... &t=47#p449

and this: http://diybookscanner.org/forum/viewtopic.php?f=1&t=3

Im searching around to see if i can find any power adapters around 4-5v, I have plenty of resistors and potentiometers.

[jakegaisser]

I just made my remote button, I used 3 AA batteries, an expansion header USB port from a computer case, and a momentary push button.

[rob]

That's all you need! 4.5 volts, a pushbutton, and the ends of USB cables to plug into the cameras (or USB sockets if you want to save your camera cables).

[jakegaisser]

Was looking around my house for an adapter that I could use to power the cameras and the remote firing button.

I got to thinking, couldn't I use a computer power supply?

It has 5v for the firing and 3.3v for the cameras:

http://pinouts.ru/Power/atx_v2_pinout.shtml

The only thing I am wondering if any resistors or diodes should be used to protect it from too much voltage/amps. 4.5v would probably be better to use than 5v

[rob]

All the info you need is here. 5v is OK, and since an ATX power supply is supposed to be stable, then theoretically it wouldn't spike and kill your cameras. If you're worried, you might be able to adjust the voltage on the power supply (maybe) and put in a zener diode across the supply that is rated for somewhere between the power supply voltage and 5v.

But, you know, 3 1.5v batteries and a holder are easier I have no experience as to powering a camera via an external power supply.

--Rob

[Plautus]

Ha! I was just figuring this out the other night; this post would have saved me some time

I got a (5V, .7A) cell phone charger that had lost its mate at a thrift store. Don't get one of those heavy transformer ones if you go this route, skinny and light is the way. I just cut off the proprietary plug, revealing two wires. I figured out which was the anode with a multimeter, and attached that to the +5V USB pin, with ground attached to the negative of the power supply. I put the momentary switch in between the positive and the USB pin 1, and that caused it to work with SDM installed. I measured the PS at 5.18V, so when I make a permanent switch setup, I may follow Dan's advice I saw in another thread and put a diode in series before pin 1, which should lower the voltage by about .7V.