can I downscale a powersupply brick to power my HDD and enclosure?

[newtoCaps101]

Re: can I downscale a powersupply brick to power my HDD and enclosure?

And here are the pictures of the power supply brick I salvaged from the lcd monitor and the enclosure of my hard disk. as you can see the power brick has plenty of room and cooling for me to be able to attach the 7805CV on to.

So just tell me if you guys want some more pictures(of the PCB perhaps)? I think I understand the diagram very well now, but let me know where should I start soldiering.

[tom66]

Re: can I downscale a powersupply brick to power my HDD and enclosure?

It looks like that might have a 5V output anyway, as it has USB.

[newtoCaps101]

Re: can I downscale a powersupply brick to power my HDD and enclosure?

It looks like that might have a 5V output anyway, as it has USB.

well i think it can (use) the 5V when i install the hdd in it and the usb connector is used to connect my hdd to my computer, but other than that i think the power brick will need to output the 5v for it to use. check out the last page, I posted pictures of the original power brick

[mariushm]

Re: can I downscale a powersupply brick to power my HDD and enclosure?

That laptop brick looks nice.

On the ouput you have two wires, a black and a white one. Black is probably Ground and White is probably 12v.

Cut them at the base of that cable protection and remove the insulation for a short distance. Later on, if you want you can desolder them from the bottom of the board but if you don't have a powerful soldering tool don't bother, sometimes it's hard to desolder lead free solder with cheap soldering guns.

Grab a multimeter and set it to 20v DC (or anything higher than 12v) or DC scale if it's automatic and touch the black and white wires with the probes (black probe on black, red probe on white) while the adapter is plugged in and running.

If it shows +12v, black is ground, white is 12v , if it shows -12v then black is 12v and white is ground.

Next, you have to make sure the heatsinks are connected to ground and not some voltage. The 7805 has the metal back side connected to Ground but there's no guarantee the other transistors or whatever it's stuck to heatsink have the back connected to ground.
Set the multimeter on DC 250v or higher, if it's not automated.

With the brick connected to the wall and running, put the black probe of the multimeter on the wire that you determined in the previous step as ground (it should be the black one) and with the other probe, touch the metal heatsinks.
Repeat the process with the meter set on AC 250-750v.

If it shows anything over about 3-5 volts, you can't tie the 7805 to those heatsinks.

Bend the pins of the regulator to the insides of the adapter, tie the capacitors to the pins then use a bit of short wire to connect the in and ground pins of the 7805 to the 12v and ground wires.

Insulate the wires and capacitor pins as best as you can.

If you can heatsink it, drill a hole by the led in the heatsink if the voltage on that side heatsink was ok (it actually looks like there is a hole there by the green led already), put a drop of cpu thermal paste on the back of the voltage regulator and screw it on the metal.
If you can't heatsink it... drill a hole in the top of that adapter brick,find some metal to act as heatsink, put some thermal paste between metal and 7805, put a screw through both and the adapter cover and screw the regulator to the top cover.

Last, connect the black, white and out wire coming from the 7805 to the black , red and yellow cables from your old adapter. Black should be ground, red should be 5v, yellow should be 12v.

[lti]

Re: can I downscale a powersupply brick to power my HDD and enclosure?

Why couldn't you just measure the resistance from the ground wire to the heatsinks?

[mariushm]

Re: can I downscale a powersupply brick to power my HDD and enclosure?

His adapter may not have the ground pin in the mains connector actually soldered onto the pcb. I can't determine that from the pictures.

There are adapters that don't have ground, yet still use the universal sockets.

I felt it was just safer to measure the voltage... more reliable. But maybe I'm wrong, feel free to contradict me.

[newtoCaps101]

Re: can I downscale a powersupply brick to power my HDD and enclosure?

I did it!!

Hey mariushm thank you for the all the help and instructions, mad respects for you. I actually looked at your reply half way through working on it last night, then remembered about using the multimeter

but i finished it and was able to put everything inside the adaptar, it had some empty space and I used some thinner wire to put the caps in those empty spaces. the thing also had a huge heatsink and holes pretty much on both sides, found a good location and used some cpu grease and mounted the 7805 with a small computer screw

Sorry I didnt take any pics but it looked pretty good, I was so excited I just finished the thing this morning and superglued the adapter case back together (the screw holes were broken but I used one to mount the PCB to the case). You'd be happy to know that I used color coded heatshrink and tried to keep everything as neat as I could. very happy, my hard drive enclosure seems to power up and work now, running a hard drive in it right now too

I hope it stays that way, I am glad I salvage parts when I can, well I'm off to salvage whatever else I can from the old broken adapter and whatever comes my way.

Thanks for everything, I guess if it or something like that ever breaks down I will be back