I took a conventional power board (just an extension lead would work, the board just made it more practical for my use), stripped the outer insulation only (very carefully so I didn't nick the inner insulation) for about 8 inches or so. I then wound the "active" 5 turns clockwise, and the "neutral" 5 turns anticlockwise and stacked them one on top of the other. With some electrical insulating tape, I wrapped them all together sort-of neatly to make this nice tidy loop. The Earth wire is wrapped around the base of the coil to keep it out of the way. NONE of the conductors were touched nor the insulation cut, no electrical work need be done at all.
The finished unit is convenient and neat enough, safe, simple to use. Easy to plug in the computer, monitor, printer or TV, DVD, Amp etc.
In use, simply clip the clamp-meter through the loops and read the current. This amplifier produces a 10* reading - so 0.1A is actually 0.01A.
Great for measuring current draw of small devices, or standby current of things.
Hope someone else gets some use out of it.[ Parent ]
But, I'm guessing that it's going to be hard/impossible for them to correct for power factor, ie you'll get a VA estimate (from a A measurement) rather than true W, which seems to make for up to a factor of 2 error in a couple of devices I know of.
Rgds
Damon[ Parent ]
take it easy[ Parent ]
I've got the prong-type meters. Can I add a shunt without replacing anything in the box? Any links to shunts or suggestions on what to look for? take it easy[ Parent ]
Do you want an elegant or a quick & dirty solution? You can use some nichrome wire, copper.. anything. For nichrome wire about 20 or so strands about 2 inches long should get you in the ball park. Each of those values is +/- 100%, so experiment, just use enough material to keep the temperature down & stable.
If you make one and it works well, build 20. Tremendously easier than building 20 different ones over 10 years, something I never learned.
Achieving high accuracy from sh*ty equipment is in some ways a lost art, find an old electrical engineering book from the 1910's and you will find a good fifty different methods to calibrate and compensate for every piece of test equipment.[ Parent ]
You could've just linked to Make Your Own Shunts and been done with it. Thanks anyway.
