View Full Version : [Interesting] Cool DIY Power Meter

02-25-2008, 03:06 PM

Not sure if comprehensive instructions are posted yet, but they said if you want to build one, to contact them and they'll provide additional details. Pretty cool project, looks easy enough to do too!

02-25-2008, 04:06 PM
HaHa, I love it. The next time someone calls here asking if we have cases for the Phidgets I'm telling them to use a mason jar.

02-25-2008, 04:20 PM
HaHa, I love it. The next time someone calls here asking if we have cases for the Phidgets I'm telling them to use a mason jar.

I like it too, gives it a sort of rustic appearance, and works well as an insulator in case something were to short. Working with AC current always frightens me a bit....

Droid Works
06-06-2008, 05:58 AM
Very cool, I love seeing stuff like this.

06-06-2008, 07:00 AM
DANGER: The EnerJar's circuitry involves 120-volt AC line voltage. Improper care can result in potentially fatal electrical shock. Do not attempt this project if you are unsure of proper safety procedures. The plans for EnerJar are provided without warranty and the designers cannot be held liable in the result of property damage, personal injury, or death.

The disclaimer alone makes me want to build one!

Droid Works
06-06-2008, 07:03 AM
The disclaimer alone makes me want to build one!

Danger = fun...lol

06-06-2008, 02:24 PM
I'm one of those stubborn types that never wants to go downstairs and fumble with the fuse box so I cheat and work on live AC all the time. I can't even count how many times I've zapped myself. I had a friend over helping me swap out my stove and I was cutting the wires in the back...
"Did you kill the power?"
"Oh no, it's fine I just clip one at a time..." *BOOM* (very large flash, half the tip of one side of the pliers blows off as friend literally dives for cover.)

Friend turning back slowly with look of complete disbelieve on face. "WTF man?!?! Are you crazy? What is wrong with you?"
Matt, laughing hysterically. "Hmmm, I totally forgot about bridging to ground on all this backplate metal I guess... do we have any more pliers up here?"

I can hear Jodie hitting her head on her desk right now :D

06-06-2008, 03:01 PM
At the risk of one-upsmanship but was invoked by name -

Lest ye forget, I'm a licensed electrician (C10/C7). I *earned* the title of "Sparky"... I was demo'ing some conduit in a fire protection company we were putting cameras in. The idiots that they had do the initial demo had disconnected all the neutral wires, but had left the hots all the way through the circuit. You know that funny feeling you get right before the proverbial fecal material impacts the rotating oscillating blades? So I'm on a 15' ladder sawzall'ing this and I think "I probably should have held a screamer up to that pipe..." and am just pulling the saw back to stop when BWAAAAM! 80A/220v/3phase. The saw was triple insulated and battery powered. Blew the whole front of my hitachi saw off and welded the exploded DeWalt blade to the conduit in three places. Knocked me off the ladder and onto my back. THEN, it gets worse. That wire is still hot. No neutral = no breaker. Oh, and the office was running in the middle of the day when I had to throw the 700A mains out at the street. :) Bad day. The 70yr old retired master electrician that was helping with the job made me a necklace from a piece of the blade and had written "Sparky" on it. Still a treasured possession.

That said, nailing cutters on 110? Sheesh, how many times a day? I don't even replace 'em anymore until the blades aren't usable. (And yes, these are my current-use top-shelf Klein 1412's in the picture...) Also notice the weld up on the top/middle where the outer edge hits the box and blows through the cutting blades... :)



06-06-2008, 03:13 PM
I rewired a hallway light and my entire bedroom without turning off the power (added 2 drops and moved wires around in two other boxes.)



PS: That damn hallway light got me like 5 times though. I was cussing up a storm.

06-06-2008, 03:21 PM
Gees, you two are lucky to be here. Glad you though.

06-06-2008, 03:50 PM
Moving hot wires around is a little frightening. I try not to do that. Wiring, new work, and old work, sure - I'll run that hot. Backpulling hot wires is something I avoid - so you got me there! ;)

4mem - I don't know any professional electrician that turns the power off. I've been on jobs where there's guys wiring multiphase 600v 2KA mains from the pole with the pole hot (right up until an OSHA inspector shows up and tags the job.. ;) )

06-06-2008, 04:06 PM
oh yeah? Well, when I was just old enough to walk, my mom said that I was in her bedroom and grabbed one of her earrings and ran over to the light socket and stuck it right in, and it shot me like 8 ft back on my ass, so there:p

06-06-2008, 04:11 PM
That explains a LOT, Alex. More than you know. No, really - more than you know... :robotsurprised: :p:p:p

06-07-2008, 12:50 PM
"I probably should have held a screamer up to that pipe..."

You kids and your new fangled “toys” back in the day that is what the “old” straight edge screw drivers were for … “small spark = low leg, small spark = low leg, POW – hey where did the screw driver go = hot leg”.

06-07-2008, 01:01 PM
That gets a little trickier when you have multiphase - or a few hundred amps behind it. ;)

Or when I really was a kid, building a power supply for a laser, and discovering how DC/RF really CAN jump out and touch you. I still have the burn scars (entry on the middle finger, exit on the wrist) as reminders that RF is scary stuff...

06-08-2008, 08:03 AM
Without disrespecting the project – after all it won an award. I am just asking…
But couldn’t you accomplish the same objective by installing a coil on the “hot wire” behind the breaker tied to an “amp clamp” type DIY circuit? Then tie it to a stamp or similar collection / recording device? Basically a smart amp clamp. Or did I miss the whole point of the project???