How to open a power brick?

[davidspalding]

What a hilarious thread ... did any of y'all have a nice Christmas/Hannukah/Kwanza/Whatever?

Bill is quite right, voltage isn't what kills you, it's the current. A rule I learned in USCG Avionics was, "1 mA tickles, 10 mA you can't let go, 100 mA you're dead." We did some controlled demonstrations in a training lab to indicate just how little current it takes to effect the muscles' ability to release. Scary *#@(, I can tell you, as I was working with R/Ts and other devices with high voltage, and brutish current sources. Dead man sticks and grounding wands were never more than 15' away.

And of course, yes, you never want to grasp a live circuit with both hands, sending the current path across your chest. I watched aghast at a MYTHBUSTERS (US cable TV reality show) episode in which they made an Ark of the Covenant with electrical contacts on the lid, to see if someone might have a religious experience from an electrical shock. Or something. One after another of the participants grasped the thing with both hands, and jumped back yowling, describing the strong shock they'd got. Much laughter, much taunting and baiting of others to try it. I fired off a seething e-mail to the producers ... encouraging tv viewers to reenact such a foolhardy practice was reckless even for slapstick infotainment.

In the same vein, recommending to strangers that they attempt to repair electrical devices without thought of the recipient's abilities isn't wise. Just because I know how to do it, doesn't mean a casual reader here has my skill and background. Happy new year, everyone, may your 2008 be filled with 3-prong GFCI safety galore.

[phool@round]

Like I've said a time or two already, nobody will ever know if I did or didn't take it apart.......... I'm still here!

My question was not irresponsible nor anyone's reply to it. Everyone has played their part. I'm very satisfied. In case anyone's curious about my qualifications, I'm currently a 25U in the Gaurd. I didn't think I needed to post my electrical or electronic qualifications but it's not a bad idea........lol.

At my age it will be from high colesterol..... and stress. Where's that Twinkie..... I need a fix.

[kensplace]

It's a transformer inside, nothing exotic to look at.

Unless you have a very odd power brick for your laptop it wont be a transformer inside, it will be a switch mode power supply (which probably may have a small transformer as part of the circuit, but certainly not a transformer like found in old style psu's where a transformer did all the work of stepping down the voltage)


Pretty nasty stuff, especially if you cant seal it up properly and the top comes off, exposing high voltages to the outside world....

[phool@round]

......if I've never opened one up I wouldn't know "whats" inside. It could be.......magic! Intel has a sticker on my laptop, that way I know Intel is inside....

Something is being transformed......what goes in is AC, what comes out is ....DC. It's all a big mystery......maybe it's woodland fairies.

I was under the impression that anything that increases or decreases AC voltage is considered a "transformer". I'm sure there *might be* a toriodal coil or two.....but I don't know of course.

Next time someone asks me what the black thingy does I'll remember to tell them it switch mode power supplies.

No electrons (or persons) have been harmed in the discussion of this topic...... they've all been grounded. No more bedtime stories for either and they must go to bed early.

[BeeJayEmm]

@phool,
Since you asked in your initial post whether opening the supply was wise or not, you're obviously no "phool". I think it partly comes down to, as Dirty Harry famously said, "a man's got to know his limitations." As in Ray's post, I have successfully repaired the DC cable on two AC adapters for guitar effects boxes. Whether a TP power brick is more complicated or dangerous, I can't say. Many posters here think so. But I've been doing this sort of thing since I fixed a walkie-talkie in the seventh grade, circa 1970. I know that, if the brick is unplugged, it can't harm you to open it and look inside. Just be careful of what you decide to do next!

Many thanks to Paul Unger for a great tip! I have added a velcro strap to all my power supply cords just for this purpose.

Brian

[phool@round]

Yes BeeJayEmm, (Motorcity Madman) absolutely correct.......... one heckuva sense of humor too.

It's not so much being wise as I was being a sweatheart to get an answer.......and look what has been bestowed upon ME! If I was a woman I'd be [censored], no flowers just stems and stalks. Feeling kinda ugly......

I hear that there might be BIG caps in there (someone started a rumor) about the size of a 49 Buick they say. They could soil some perfectly clean laundry if they're still holding a charge. Of course, some people don't seem to notice when they need a laundry change...... so who knows? It becomes a Tide versus Clorox debate then....

Ever notice the battery charge light on your laptop? Notice how it will stay on a few seconds after you unplug? Or, some power bricks have indicator lights and they too will take a second to go out.......must be the caps, or maybe it's the lifeforce being sucked out by a wizard's incantation...... I still don't know.

I guess THE question is, would I advise someone else to open one to find out? No one will ever know.........

There are "do it yourselfers" and there are "do it to yourselfers" and I am of the former, not the later (although I do climb ladders).

By the way, did you folks get any snow out of the last system, up here in the almost great white north (Canada IS the GWN) we where dumped on......been out all morn just plowing the drive......nice to be a tele-commuter today....no I696 fur balls anymore.

(Also, I think it takes more juice to play Solitare then to shape a signal, but then again, what do I know......)

[bill bolton]

I know that, if the brick is unplugged, it can't harm you to open it and look inside.

Switched mode power supplies can store significant charge in their internal High Voltage capacitors for quite a while after being turned off, so unlike guitar effects box power supplies, they can certainly "harm you" even when unplugged.

Cheers,

Bill B.

[jdhurst]

Bill B.'s advice should not be ignored. When I broke open my (not-working) power brick: (a) it had not been plugged in for a long while; and (b) I grounded key points inside (coil terminals and the like). ... JDH

[bill bolton]

The original poster has asked that the thread be locked.

Since I think we are done with useful discussion on this topic anyway, that seems like a good idea!

Cheers,

Bill B. (Admin)